WO2025187302A1 - Ion implantation apparatus and ion extraction apparatus - Google Patents

Abstract

This ion implantation apparatus comprises: an ion source 20 for generating plasma including desired ions; an extraction unit 22 for extracting an ion group including the desired ions via a first opening OP1 in the ion source 20 to generate an ion beam IB; and an injection processing chamber for irradiating a wafer with the ion beam IB. The extraction unit 22 includes: a reference electrode 22b to which a reference potential V_gnd is applied, the reference electrode 22b having a second opening OP2 through which the ion beam IB passes from downstream to upstream in a traveling direction of the ion beam IB; a suppression electrode 22a to which a suppression potential V_sup lower than the reference potential V_gnd is applied, the suppression electrode 22a having a third opening OP3 through which the ion beam IB passes; and a movable conductor 22e having a fourth opening OP4 through which the ion beam IB passes, and having a variable distance from the first opening OP1 in the traveling direction.

Description

Ion implantation device and ion extraction device

This disclosure relates to an ion implantation device and an ion extraction device.

In the semiconductor device manufacturing process, a standard process is to implant ions into semiconductor wafers (also known as the ion implantation process) in order to change the conductivity or crystalline structure of the semiconductor.

Japanese Patent Application Laid-Open No. 2019-169407

The ion beam irradiated onto the semiconductor wafer is extracted from an ion source that generates plasma. Depending on how the ions that make up the ion beam are extracted from the ion source, the manner in which the ion beam interacts with the wafer changes, affecting the results of the ion implantation process.

One exemplary objective of an embodiment of the present disclosure is to provide a technique that can appropriately extract a group of ions from an ion source.

In order to solve the above problems, one embodiment of the ion implantation apparatus of the present invention comprises an ion source that generates plasma containing desired ions, an extraction unit that extracts a group of ions containing the desired ions from a first opening in the ion source to generate an ion beam, and an implantation processing chamber that irradiates the ion beam onto a wafer. The extraction unit comprises, from downstream to upstream in the direction of ion beam propagation, a reference electrode that has a second opening through which the ion beam passes and to which a reference potential is applied, a suppression electrode that has a third opening through which the ion beam passes and to which a suppression potential lower than the reference potential is applied, and a movable conductor that has a fourth opening through which the ion beam passes and whose distance from the first opening in the direction of propagation is variable.

Another aspect of the present invention is an ion extraction device. This device comprises an ion source that generates plasma containing desired ions, and an extraction unit that extracts a group of ions containing the desired ions from a first opening in the ion source to generate an ion beam. The extraction unit comprises, from downstream to upstream in the direction of ion beam propagation, a reference electrode that has a second opening through which the ion beam passes and to which a reference potential is applied, a suppression electrode that has a third opening through which the ion beam passes and to which a suppression potential lower than the reference potential is applied, and a movable conductor that has a fourth opening through which the ion beam passes and whose distance from the first opening in the direction of propagation is variable.

In addition, any combination of the above components, or any mutual substitution of the components or expressions of this disclosure between methods, devices, systems, etc., are also valid aspects of this disclosure.

A non-limiting exemplary embodiment of the present disclosure provides a technique for appropriately extracting ions from an ion source.

1 is a top view showing a schematic configuration of an ion implantation apparatus according to an embodiment; 1 is a side view showing a schematic configuration of an ion implantation apparatus according to an embodiment. FIG. 2 is a front view showing a schematic configuration of a first holding device and a second holding device. 4A and 4B are top views schematically showing the horizontal orientation of the first workpiece held by the first holding device. 5(a) to 5(c) are side views schematically showing the vertical orientation of the first workpiece held by the first holding device. 10A and 10B are front views showing an example of the operation of the first holding device and the second holding device. 10A and 10B are front views showing an example of the operation of the first holding device and the second holding device. 10A and 10B are front views showing an example of the operation of the first holding device and the second holding device. 10A and 10B are front views showing an example of the operation of the first holding device and the second holding device. 3 is a flowchart showing the flow of an ion implantation method according to an embodiment. 10 is a flowchart showing the flow of an ion implantation method according to a modified example. FIG. 10 is a top view showing a schematic configuration of an ion implantation apparatus according to another embodiment. FIG. 10 is a side view showing a schematic configuration of an ion implantation apparatus according to another embodiment. FIG. 2 is a front view schematically showing the movable range of the beam profiler. 1 is a cross-sectional view showing a schematic configuration of an angle measurement device according to a first embodiment. FIG. 16(a) is a plan view showing a schematic configuration of an entrance surface having an entrance opening, and FIG. 16(b) is a plan view showing a schematic configuration of an exit surface having an exit opening. 10 is a graph showing an example of a scan voltage waveform of a scan beam and a time waveform of a potential difference in an angle measurement device. Figure 18(a) is a graph showing an example of the time waveform of the beam current detected by the angle measurement device, and Figure 18(b) is a graph showing an example of the angular distribution of the scan beam calculated using the time waveform of the beam current in Figure 18(a). FIG. 10 is a plan view showing a schematic configuration of an incident surface of an angle measurement device according to a second embodiment. FIG. 10 is a plan view showing a schematic configuration of an exit surface of an angle measurement device according to a second embodiment. FIG. 10 is a cross-sectional view showing a schematic configuration of an electrode assembly according to a second embodiment. FIG. 10 is a plan view showing a schematic configuration of a current measuring device according to a second embodiment. FIG. 10 is a cross-sectional view showing a schematic configuration of an electrode assembly according to a modified example. FIG. 11 is a plan view showing a schematic configuration of an incident surface of an angle measurement device according to a third embodiment. FIG. 11 is a plan view showing a schematic configuration of an exit surface of an angle measurement device according to a third embodiment. FIG. 10 is a cross-sectional view showing a schematic configuration of an electrode assembly according to a third embodiment. FIG. 10 is a plan view showing a schematic configuration of a current measuring device according to a third embodiment. FIG. 10 is a cross-sectional view showing a schematic configuration of an electrode assembly according to a modified example. 1 shows an ion extraction device according to a first embodiment. 1 shows an ion extraction device according to a first embodiment. 1 shows an ion extraction device according to a first embodiment. 1 shows an ion extraction device according to a first embodiment. 1 shows an ion extraction device according to a first embodiment. 1 shows an ion extraction device according to a first embodiment. 1 shows an ion extraction device according to a first embodiment. 1 shows an ion extraction device according to a second embodiment. 1 shows an ion extraction device according to a second embodiment. 1 shows an ion extraction device according to a second embodiment. 1 shows an ion extraction device according to a second embodiment. 1 shows an ion extraction device according to a second embodiment. 1 shows an ion extraction device according to a second embodiment. 1 shows an ion extraction device according to a third embodiment. 10 shows an ion extraction device according to a third embodiment. 1 shows an ion extraction device according to a third embodiment. 10 shows an ion extraction device according to a third embodiment. 1 shows an ion extraction device according to a third embodiment. 10 shows an ion extraction device according to a third embodiment.

Below, with reference to the drawings, a detailed description will be given of embodiments for implementing an ion implantation apparatus and an ion implantation method according to the present disclosure. Note that in the description of the drawings, identical elements are given the same reference numerals, and duplicate descriptions will be omitted where appropriate. Furthermore, the configurations described below are examples and do not in any way limit the scope of the present invention.

FIG. 1 is a top view showing the schematic configuration of an ion implantation apparatus 10 according to an embodiment. FIG. 2 is a side view showing the schematic configuration of the ion implantation apparatus 10 according to an embodiment. The ion implantation apparatus 10 is configured to perform ion implantation processing on the surfaces of workpieces W1 and W2. The workpieces W1 and W2 are, for example, substrates, such as semiconductor wafers. For ease of explanation, the workpieces may be referred to as "substrates" or "wafers" in this specification, but this is not intended to limit the target of the implantation processing to a specific object. The workpieces may also be large substrates (e.g., glass substrates or resin substrates) used in the manufacture of flat panel displays (FPDs).

The ion implantation device 10 is configured to irradiate the entire processing surface of the workpieces W1 and W2 with a spot-shaped ion beam by scanning the ion beam back and forth in a predetermined scanning direction and moving the workpieces W1 and W2 back and forth in a direction intersecting the scanning direction. The ion implantation device 10 includes a beam generation device 12, an implantation processing chamber 14, a transport device 16, and a control device 18.

The beam generator 12 is configured to generate an ion beam and transport the ion beam to the implantation processing chamber 14. The implantation processing chamber 14 contains workpieces W1 and W2 to be implanted. In the implantation processing chamber 14, the ion beam provided by the beam generator 12 is irradiated onto the workpieces W1 and W2. The transport device 16 is configured to transport the workpieces W1 and W2 before implantation processing into the implantation processing chamber 14 and transport the workpieces W1 and W2 after implantation processing out of the implantation processing chamber 14. The control device 18 is configured to control the overall operation of the various devices that make up the ion implantation apparatus 10. The ion implantation apparatus 10 is equipped with a vacuum exhaust system (not shown) for providing the desired vacuum environment for the beam generator 12, implantation processing chamber 14, and transport device 16.

The beam generator 12 comprises, in order from the upstream side of beamline A, an ion source 20, an extraction unit 22, a mass analysis unit 24, a beam shaping unit 26, a beam scanning unit 28, a beam collimation unit 30, an acceleration/deceleration unit 32, and an energy analysis unit 34. Here, beamline A is used for convenience of explanation and is synonymous with the ideal beam trajectory designed when the ion beam is not scanned by the beam scanning unit 28. Furthermore, "upstream" of beamline A refers to the side closer to the ion source 20, and "downstream" of beamline A refers to the side closer to the implantation processing chamber 14 (or beam stopper 38).

The beam generator 12 is configured so that the beamline A bends midway. The direction of travel of the beamline A changes at the mass analysis unit 24 and the energy analysis unit 34. The beamline A is configured to extend in a horizontal plane perpendicular to the vertical direction. For ease of explanation, the direction of travel of the ion beam traveling along the beamline A is referred to as the z direction, the vertical direction as the y direction, and the direction perpendicular to the y and z directions as the x direction. In particular, the direction of travel of the beamline A from the ion source 20 to the mass analysis unit 24 is referred to as the z1 direction, and the direction perpendicular to the y and z1 directions as the x1 direction. Furthermore, the direction of travel of the beamline A from the mass analysis unit 24 to the energy analysis unit 34 is referred to as the z2 direction, and the direction perpendicular to the y and z2 directions as the x2 direction. Furthermore, the direction of travel of the beamline A downstream of the energy analysis unit 34 is referred to as the z3 direction, and the direction perpendicular to the y and z3 directions as the x3 direction.

The ion source 20 is configured to generate ions that constitute an ion beam. The ion source 20 includes an arc chamber 20a. The arc chamber 20a has an internal space 20b in which plasma is generated. The arc chamber 20a has a roughly rectangular box shape that defines the internal space 20b. The arc chamber 20a has a front slit 20c for extracting ions from the plasma generated in the internal space 20b. The front slit 20c has a slit shape with a long opening width in the horizontal direction (x1 direction) and a short opening width in the vertical direction (y direction). In other words, the horizontal opening width of the front slit 20c is larger than the vertical opening width of the front slit 20c.

The ion source 20 includes a source magnet device 20d. The source magnet device 20d is configured to apply a horizontal (x1 direction) magnetic field B1 to the internal space 20b of the arc chamber 20a. By applying the magnetic field B1, the source magnet device 20d increases the generation efficiency of plasma generated in the internal space 20b of the arc chamber 20a. The direction in which the source magnet device 20d applies the magnetic field B1 corresponds to the longitudinal direction of the front slit 20c.

The extraction unit 22 is provided downstream of the ion source 20. The extraction unit 22 extracts ions from the ion source 20 to generate an ion beam. The extraction unit 22 is configured to extract ions from plasma generated in the internal space 20b of the arc chamber 20a. The extraction unit 22 includes a first extraction electrode 22a and a second extraction electrode 22b. The first extraction electrode 22a is provided downstream of the arc chamber 20a, and the second extraction electrode 22b is provided downstream of the first extraction electrode 22a. A negative suppression voltage is applied to the first extraction electrode 22a. A ground voltage is applied to the second extraction electrode 22b. A positive extraction voltage is applied to the arc chamber 20a.

The first extraction electrode 22a has a first extraction opening 22c through which the ion beam passes. Similar to the front slit 20c, the first extraction opening 22c has a slit shape with a long opening width in the horizontal direction (x1 direction) and a short opening width in the vertical direction (y direction). In other words, the horizontal opening width of the first extraction opening 22c is larger than the vertical opening width of the first extraction opening 22c. The second extraction electrode 22b has a second extraction opening 22d through which the ion beam passes. Similar to the front slit 20c, the second extraction opening 22d has a slit shape with a long opening width in the horizontal direction (x1 direction) and a short opening width in the vertical direction (y direction). In other words, the horizontal opening width of the second extraction opening 22d is larger than the vertical opening width of the second extraction opening 22d.

The ion beam extracted by the extraction unit 22 may be a ribbon-shaped beam that spreads in the horizontal direction (x1 direction). The horizontal size of the ribbon-shaped beam can be increased by increasing the horizontal opening widths of the front slit 20c, first extraction opening 22c, and second extraction opening 22d. As a result, it becomes easier to increase the beam current of the ion beam extracted from the ion source 20.

The mass analysis unit 24 is located downstream of the extraction unit 22. The mass analysis unit 24 is configured to select the required ion species from the ion beam extracted by the extraction unit 22 through mass analysis. The mass analysis unit 24 includes a mass analysis magnet device 24a, a mass analysis slit 24b, and an injector Faraday cup 24c.

The mass analysis magnet device 24a applies a magnetic field B2 to the ion beam, deflecting it along different paths depending on the value of the ion's mass-to-charge ratio M = m/q (m is mass, q is charge). The mass analysis magnet device 24a applies a magnetic field B2 in the vertical direction (-y direction) and deflects the ion beam horizontally (x1 direction). The strength of the magnetic field B2 applied by the mass analysis magnet device 24a is adjusted so that ion species with the desired mass-to-charge ratio M pass through the mass analysis slit 24b. The ion beam passing through the mass analysis slit 24b is deflected, for example, by 90 degrees by the mass analysis magnet device 24a.

The mass analysis slit 24b is located downstream of the mass analysis magnet device 24a. The mass analysis slit 24b has a slit shape with a short opening width in the horizontal direction (x2 direction) and a long opening width in the vertical direction (y direction). In other words, the vertical opening width of the mass analysis slit 24b is larger than the horizontal opening width of the mass analysis slit 24b.

The mass analysis slit 24b may be configured so that the opening width (i.e., slit width) in the horizontal direction (x2 direction) is variable in order to adjust the mass resolution. The mass analysis slit 24b may be configured so that it is made up of two beam shields that are movable in the slit width direction, and the slit width is adjustable by changing the distance between the two beam shields. The mass analysis slit 24b may be configured so that the slit width is variable by switching to one of multiple slits with different slit widths.

The injector Faraday cup 24c is located downstream of the mass analysis slit 24b. The injector Faraday cup 24c measures the beam current of the mass-analyzed ion beam that passes through the mass analysis slit 24b. The injector Faraday cup 24c can measure the mass analysis spectrum of the ion beam by measuring the beam current while changing the magnetic field strength of the mass analysis magnet device 24a. The measured mass analysis spectrum can be used to calculate the mass resolution of the mass analysis unit 24.

The injector Faraday cup 24c is configured so that it can be inserted into and removed from beamline A by the operation of the injector driver 24d. The injector driver 24d moves the injector Faraday cup 24c in a direction (e.g., the x2 direction) perpendicular to the z2 direction in which beamline A extends. When the injector Faraday cup 24c is positioned in beamline A as shown by the dashed line in Figure 1, it blocks the ion beam traveling downstream. On the other hand, when the injector Faraday cup 24c is retracted from beamline A as shown by the solid line in Figure 1, the blockage of the ion beam traveling downstream is released.

A magnetic shield 23 may be provided between the extraction section 22 and the mass analysis section 24. The magnetic shield 23 is configured to suppress magnetic field interference between the magnetic field B1 applied to the ion source 20 and the magnetic field B2 applied to the mass analysis section 24. The magnetic shield 23 is made of a magnetic material such as an electromagnetic steel plate. The magnetic shield 23 has a passage opening 23a that allows the ion beam traveling from the extraction section 22 toward the mass analysis section 24 to pass through. Similar to the front slit 20c, the passage opening 23a may have a slit shape with a long opening width in the horizontal direction (x1 direction) and a short opening width in the vertical direction (y direction). In other words, the horizontal opening width of the passage opening 23a may be larger than the vertical opening width of the passage opening 23a.

The beam shaping unit 26 is provided downstream of the mass analysis unit 24. The beam shaping unit 26 is configured to shape the ion beam that has passed through the mass analysis unit 24 into a desired cross-sectional shape and convergence/divergence angle. The beam shaping unit 26 includes a lens device that adjusts at least one of the cross-sectional shape and convergence/divergence angle of the ion beam. The beam shaping unit 26 is configured, for example, to focus a ribbon-shaped ion beam that spreads horizontally and shape it into a spot-shaped ion beam.

The beam shaping unit 26 includes multiple lens devices, for example, three lens devices 26a, 26b, and 26c. The three lens devices 26a to 26c are configured, for example, as electric field triple quadrupole lenses (also called triplet Q lenses). By using a combination of multiple lens devices, the beam shaping unit 26 can independently adjust the convergence or divergence of the ion beam in each of the horizontal direction (x2 direction) and vertical direction (y direction). The beam shaping unit 26 may also include a magnetic field lens device. The beam shaping unit 26 may also include a lens device that uses both electric and magnetic fields to shape the ion beam.

The beam scanning unit 28 is provided downstream of the beam shaping unit 26. The beam scanning unit 28 is configured to generate a scan beam SB by scanning the ion beam back and forth in a predetermined scan direction. The beam scanning unit 28 can also be considered a beam deflection device that deflects the ion beam shaped by the beam shaping unit 26 in the predetermined scan direction. The beam scanning unit 28 is configured so that the scan direction is a direction different from the horizontal direction, for example, so that the scan direction is the vertical direction (y direction).

The beam scanning unit 28 includes a pair of scanning electrodes 28a, 28b facing each other in the vertical direction (y direction). The pair of scanning electrodes 28a, 28b are connected to a variable voltage power supply (not shown). By periodically changing the voltage applied between the pair of scanning electrodes 28a, 28b, the electric field generated between the pair of scanning electrodes 28a, 28b is changed, thereby deflecting the ion beam at various angles. As a result, the ion beam is scanned across the entire scanning range in the vertical direction (y direction). In Figure 2, the arrow Y illustrates the scanning direction and scanning range of the ion beam, and the dashed lines indicate multiple trajectories of the ion beam within the scanning range. Note that the beam scanning unit 28 may be a magnetic field type instead of an electric field type. The beam scanning unit 28 may also be equipped with a magnet device for deflecting the ion beam.

The beam collimator 30 is provided downstream of the beam scanning unit 28. The beam collimator 30 is configured to make the direction of travel of the ion beam scanned back and forth by the beam scanning unit 28 parallel to the direction of beamline A. The beam collimator 30 has multiple arc-shaped collimator lens electrodes 30a, 30b, each with an ion beam passage slit located in the center in the horizontal direction (x2 direction). The collimator lens electrodes 30a, 30b are connected to a high-voltage power supply (not shown), and an electric field generated by applying a voltage acts on the ion beam to collimate the direction of travel of the ion beam. Note that the beam collimator 30 may be a magnetic field type instead of an electric field type. The beam collimator 30 may also be equipped with a magnet device for deflecting the ion beam.

The acceleration/deceleration unit 32 is provided downstream of the beam collimator 30. The acceleration/deceleration unit 32 is configured to accelerate or decelerate the scan beam collimated by the beam collimator 30. The acceleration/deceleration unit 32 is an electrostatic acceleration/deceleration device, and accelerates or decelerates the ion beam by utilizing the potential difference between a first potential applied to the upstream side of the acceleration/deceleration unit 32 and a second potential applied to the downstream side of the acceleration/deceleration unit 32.

The energy analysis unit 34 is provided downstream of the acceleration/deceleration unit 32. The energy analysis unit 34 is configured to analyze the energy of the ion beam and pass ions having the desired energy toward the implantation processing chamber 14. The energy analysis unit 34 is an angular energy filter (AEF) that deflects the ion beam horizontally and selects the desired energy based on the deflection angle θ. The deflection angle θ is, for example, between 10 degrees and 20 degrees, and is approximately 15 degrees. The energy analysis unit 34 includes an AEF electrode pair 34a, 34b and an energy analysis slit 34c.

The AEF electrode pair 34a, 34b are arranged to face each other in a direction perpendicular to the scan direction. The AEF electrode pair 34a, 34b are arranged to face each other in the horizontal direction (x2 direction or x3 direction). The AEF electrode pair 34a, 34b are connected to a high-voltage power supply (not shown) and apply an electric field to the ion beam to deflect it. The AEF electrode pair 34a, 34b is a deflection device that deflects the scan beam in the horizontal direction. The energy analysis slit 34c is provided downstream of the AEF electrode pair 34a, 34b.

The energy analysis slit 34c has a slit shape with a long opening width in the vertical direction (y direction) and a short opening width in the horizontal direction (x3 direction). In other words, the vertical opening width of the energy analysis slit 34c is larger than the horizontal opening width of the energy analysis slit 34c. The energy analysis slit 34c allows ion beams of the desired energy value or energy range to pass toward the workpieces W1 and W2, and blocks other ion beams.

The energy analysis unit 34 may be a magnetic field type instead of an electric field type. The energy analysis unit 34 may be equipped with a magnet device for magnetic field deflection. The energy analysis unit 34 may use both an electric field and a magnetic field, and may be equipped with an AEF electrode pair for electric field deflection and a magnet device for magnetic field deflection.

In this way, the beam generator 12 supplies the ion beam to be irradiated onto the workpieces W1 and W2 to the implantation processing chamber 14. The beam generator 12 may also be called a beamline device. The beam generator 12 is configured to generate an ion beam to achieve the desired implantation conditions by adjusting the operating parameters of the various devices that make up the beam generator 12.

The implantation processing chamber 14 is equipped with a plasma shower device 36, a beam stopper 38, a first holding device 40, and a second holding device 42.

The plasma shower device 36 is located downstream of the energy analysis section 34. The plasma shower device 36 supplies low-energy electrons to the ion beam and the surfaces (processed surfaces) of the workpieces W1 and W2 according to the beam current of the ion beam, suppressing charge-up caused by the accumulation of positive charge on the processed surfaces due to ion implantation. The plasma shower device 36 includes, for example, a shower tube 36a through which the ion beam passes, and a plasma generation section 36b that supplies electrons into the shower tube 36a. The shower tube 36a has a shape with a long opening width in the vertical direction (y direction) and a short opening width in the horizontal direction (x3 direction).

Beam stopper 38 is provided at the most downstream position of beam line A and is attached, for example, to the side wall of implantation processing chamber 14. When no workpieces W1, W2 are present in beam line A, the ion beam is incident on beam stopper 38. Beam stopper 38 is provided with multiple tuning cups 38a, 38b, 38c, and 38d. The multiple tuning cups 38a-38d are Faraday cups configured to measure the beam current of the ion beam incident on beam stopper 38. The multiple tuning cups 38a-38d are arranged, for example, at intervals in the vertical direction (y direction).

The first holding device 40 is configured to be able to hold the first workpiece W1 to be subjected to the injection process. The first holding device 40 is configured to move the first workpiece W1 held by the first holding device 40 back and forth in a direction crossing the scan beam. The first holding device 40 is configured to move the first workpiece W1 back and forth in the horizontal direction (x3 direction). The first holding device 40 is movable along a guide rail 44 extending in the horizontal direction (x3 direction).

The first holding device 40 includes a first chuck mechanism 50, a first twist mechanism 52, a first vertical angle adjustment mechanism 54, a first horizontal angle adjustment mechanism 56, and a first reciprocating mechanism 58.

The first chuck mechanism 50 is configured to contact the back surface of the first workpiece W1 and hold the first workpiece W1. The first chuck mechanism 50 includes, for example, an electrostatic chuck for holding the first workpiece W1. The first chuck mechanism 50 may also include a temperature adjustment mechanism for cooling or heating the first workpiece W1. The first chuck mechanism 50 includes a first lift mechanism for lifting the first workpiece W1 so as to separate it from the first chuck mechanism 50.

The first twist mechanism 52 rotatably supports the first chuck mechanism 50. The first twist mechanism 52 rotates the first chuck mechanism 50 around a rotation axis (also called the twist axis) extending normal to the processing surface of the first workpiece W1 held by the first chuck mechanism 50, thereby adjusting the twist angle φa1 of the first workpiece W1. The first twist mechanism 52 adjusts the twist angle φa1 between, for example, an alignment mark provided on the outer periphery of the first workpiece W1 and a reference position. Here, the alignment mark of the first workpiece W1 refers to, for example, a notch or orientation flat provided on the outer periphery of the wafer, and is a mark that serves as a reference for the crystal axis direction and angular position in the circumferential direction of the wafer.

The first vertical angle adjustment mechanism 54 rotatably supports the first twist mechanism 52. The first vertical angle adjustment mechanism 54 rotates the first twist mechanism 52 around a horizontally extending rotation axis (also called the transport tilt axis) to adjust the vertical orientation of the first workpiece W1. The vertical orientation of the first workpiece W1 can be defined by the vertical rotation angle φb1 around the horizontal rotation axis.

The first horizontal angle adjustment mechanism 56 rotatably supports the first vertical angle adjustment mechanism 54. The first horizontal angle adjustment mechanism 56 rotates the first vertical angle adjustment mechanism 54 around a rotation axis (also called the injection tilt axis) extending in the vertical direction, adjusting the horizontal orientation of the first workpiece W1. The horizontal orientation of the first workpiece W1 can be defined by the horizontal rotation angle φc1 around the vertical rotation axis.

The first reciprocating motion mechanism 58 is configured to move the first horizontal angle adjustment mechanism 56 in the horizontal direction (x3 direction). The first reciprocating motion mechanism 58 moves the first horizontal angle adjustment mechanism 56 along the guide rail 44. The first reciprocating motion mechanism 58 includes, for example, a first ball screw 58a that extends in the horizontal direction (x3 direction) along the guide rail 44. The first reciprocating motion mechanism 58 moves the first horizontal angle adjustment mechanism 56 linearly in the horizontal direction by rotating the first ball screw 58a.

The second holding device 42 is configured to be able to hold the second workpiece W2 to be subjected to the injection process. The second holding device 42 is configured to move the second workpiece W2 held by the second holding device 42 back and forth in a direction crossing the scan beam. The second holding device 42 is configured to move the second workpiece W2 back and forth in the horizontal direction (x3 direction). The second holding device 42 is movable along a guide rail 44 extending in the horizontal direction (x3 direction).

The second holding device 42 can be configured similarly to the first holding device 40. The second holding device 42 is movable in the same direction as the first holding device 40. The second holding device 42 is movable along a guide rail 44 shared with the first holding device 40. The second holding device 42 may also be configured to be movable along a guide rail different from that of the first holding device 40. In other words, the injection processing chamber 14 may be provided with a first guide rail along which the first holding device 40 moves, and a second guide rail along which the second holding device 42 moves. The second holding device 42 is movable simultaneously with the first holding device 40. The second holding device 42 is movable independently of the first holding device 40.

The second holding device 42 includes a second chuck mechanism 60, a second twist mechanism 62, a second vertical angle adjustment mechanism 64, a second horizontal angle adjustment mechanism 66, and a second reciprocating mechanism 68.

The second chuck mechanism 60 is configured to contact the back surface of the second workpiece W2 and hold the second workpiece W2. The second chuck mechanism 60 includes, for example, an electrostatic chuck for holding the second workpiece W2. The second chuck mechanism 60 may also include a temperature adjustment mechanism for cooling or heating the second workpiece W2. The second chuck mechanism 60 includes a second lift mechanism for lifting the second workpiece W2 so as to separate it from the second chuck mechanism 60.

The second twist mechanism 62 rotatably supports the second chuck mechanism 60. The second twist mechanism 62 rotates the second chuck mechanism 60 around a rotation axis (also called the twist axis) extending normal to the processing surface of the second workpiece W2 held by the second chuck mechanism 60, thereby adjusting the twist angle φa2 of the second workpiece W2. The second twist mechanism 62 adjusts, for example, the twist angle φa2 between an alignment mark provided on the outer periphery of the second workpiece W2 and a reference position.

The second vertical angle adjustment mechanism 64 rotatably supports the second twist mechanism 62. The second vertical angle adjustment mechanism 64 rotates the second twist mechanism 62 around a horizontally extending rotation axis (also called the transport tilt axis) to adjust the vertical orientation of the second workpiece W2. The vertical orientation of the second workpiece W2 can be defined by the vertical rotation angle φb2 around the horizontal rotation axis.

The second horizontal angle adjustment mechanism 66 rotatably supports the second vertical angle adjustment mechanism 64. The second horizontal angle adjustment mechanism 66 rotates the second vertical angle adjustment mechanism 64 around a rotation axis (also called the injection tilt axis) extending in the vertical direction, adjusting the horizontal orientation of the second workpiece W2. The horizontal orientation of the second workpiece W2 can be defined by the horizontal rotation angle φc2 around the vertical rotation axis.

The second reciprocating motion mechanism 68 is configured to move the second horizontal angle adjustment mechanism 66 in the horizontal direction (x3 direction). The second reciprocating motion mechanism 68 moves the second horizontal angle adjustment mechanism 66 along the guide rail 44. The second reciprocating motion mechanism 68, for example, includes a second ball screw 68a extending in the horizontal direction (x3 direction) along the guide rail 44, and by rotating the second ball screw 68a, the second horizontal angle adjustment mechanism 66 is moved linearly in the horizontal direction.

The transport device 16 comprises a first transport device 70 and a second transport device 72. The first transport device 70 and the second transport device 72 are arranged at a distance from the beamline A in the horizontal direction (x3 direction). In the example of Figure 1, the first transport device 70 is arranged at a distance from the beamline A in the -x3 direction, and the second transport device 72 is arranged at a distance from the beamline A in the +x3 direction. The first transport device 70 and the second transport device 72 are arranged, for example, so that the beam stopper 38 is located between the first transport device 70 and the second transport device 72.

The first transfer device 70 is configured to transfer the first workpiece W1 into the injection treatment chamber 14 before injection treatment and to transfer the first workpiece W1 from the injection treatment chamber 14 after injection treatment. The first transfer device 70 transfers the first workpiece W1 into the first holding device 40 and transfers the first workpiece W1 from the first holding device 40. The first transfer device 70 is equipped with, for example, a first transfer robot (not shown) for transferring the first workpiece W1. The first transfer device 70 transfers the first workpiece W1 through a first transfer port 74 provided in the side wall of the injection treatment chamber 14.

The second transport device 72 is configured to transport the second workpiece W2 into the injection processing chamber 14 before injection processing and to transport the second workpiece W2 from the injection processing chamber 14 after injection processing. The second transport device 72 transports the second workpiece W2 into the second holding device 42 and transports the second workpiece W2 from the second holding device 42. The second transport device 72 is equipped with, for example, a second transport robot (not shown) for transporting the second workpiece W2. The second transport device 72 transports the second workpiece W2 through a second transport port 76 provided in the side wall of the injection processing chamber 14.

The control device 18 controls the overall operation of the ion implantation device 10. In terms of hardware, the control device 18 is realized by elements and mechanical devices such as a computer's CPU and memory, and in terms of software, it is realized by computer programs, etc. The various functions provided by the control device 18 can be realized through the cooperation of hardware and software.

The control device 18 includes a processor 18a such as a CPU (Central Processing Unit) and a memory 18b such as a ROM (Read Only Memory) or RAM (Random Access Memory). The control device 18 controls the overall operation of the ion implantation device 10 in accordance with a program stored in the memory 18b, for example, by the processor 18a executing the program. The processor 18a may execute a program stored in an arbitrary storage device other than the memory 18b, or may execute a program obtained from an arbitrary recording medium by a reading device, or may execute a program obtained via a network. The memory 18b in which the program is stored may be a volatile memory such as a DRAM (Dynamic Random Access Memory), or may be a non-volatile memory such as an EEPROM (Electrically Erasable Programmable Read-Only Memory), flash memory, magnetoresistive memory, resistance change memory, or ferroelectric memory. Non-volatile memory, magnetic recording media such as magnetic tape and magnetic disks, and optical recording media such as optical disks are examples of non-transitory, tangible, computer-readable storage media.

The various functions provided by the control device 18 may be realized by a single device equipped with a processor 18a and memory 18b, or may be realized by the cooperation of multiple devices, each equipped with a processor 18a and memory 18b.

Figure 3 is a front view showing the schematic configuration of the first holding device 40 and the second holding device 42, and shows the configuration when viewed in the beam propagation direction (z3 direction) in the implantation processing chamber 14. In Figure 3, the first holding device 40 is positioned at the first transfer position 80, and the second holding device 42 is positioned at the second transfer position 82. The first transfer position 80 is a position for loading or unloading the first workpiece W1 into or from the first holding device 40 through the first transfer port 74. The first transfer position 80 corresponds to the position of the first transfer port 74. The second transfer position 82 is a position for loading or unloading the second workpiece W2 into or from the second holding device 42 through the second transfer port 76. The second transfer position 82 corresponds to the position of the second transfer port 76. The first transfer position 80 and the second transfer position 82 are separated in the horizontal direction (x3 direction) from the implantation position 84 for irradiating the workpieces W1 and W2 with the ion beam.

The injection position 84 is located in the center of the injection processing chamber 14 in the horizontal direction (x3 direction). The injection position 84 is located between the first transport position 80 and the second transport position 82. The injection position 84 includes an injection center position 84C, an injection left end position 84L, and an injection right end position 84R. In Figure 3, the workpieces WC, WL, and WR located at the injection center position 84C, the injection left end position 84L, and the injection right end position 84R are indicated by dashed double-dashed lines. The injection center position 84C corresponds to the position where the scan beam SB generated by the beam generating device 12 is irradiated. The injection left end position 84L is shifted to the left (+x3 direction in Figure 3) from the injection center position 84C and is set so that the entire processing surface of the workpiece WL placed at the injection left end position 84L does not overlap with the scan beam SB. The right end implantation position 84R is a position shifted to the right (in the -x3 direction in Figure 3) from the central implantation position 84C, and is set so that the entire surface to be processed of the workpiece WR placed at the right end implantation position 84R does not overlap with the scan beam SB.

The size _hB of the irradiation range of the scan beam SB in the vertical direction (y direction) is larger than the size _hW of the treatment surfaces of the workpieces W1 and W2 in the vertical direction (y direction). The size _hB of the scan beam SB in the vertical direction is, for example, 1.1 to 3 times, and preferably 1.2 to 2 times, the size _hW of the treatment surfaces of the workpieces W1 and W2 in the vertical direction.

The first holding device 40 reciprocates in the horizontal direction (x3 direction) at the injection position 84, thereby irradiating the entire processing surface of the first workpiece W1 with the scan beam SB. The first holding device 40 reciprocates within a movement range C from the injection left end position 84L to the injection right end position 84R, thereby irradiating the entire processing surface of the first workpiece W1 with the scan beam SB. The first holding device 40 moves to the first transport position 80, making it possible to load or unload the first workpiece W1. The first holding device 40 is movable between the injection position 84 and the first transport position 80. The first holding device 40 is movable over a first movable range E1 from the first transport position 80 to the injection left end position 84L. The first holding device 40 cannot move to the second transport position 82.

The second holding device 42 reciprocates in the horizontal direction (x3 direction) at the injection position 84, thereby irradiating the entire processing surface of the second workpiece W2 with the scan beam SB. The second holding device 42 reciprocates within a movement range C from the injection left end position 84L to the injection right end position 84R, thereby irradiating the entire processing surface of the second workpiece W2 with the scan beam SB. The second holding device 42 moves to the second transport position 82, making it possible to load or unload the second workpiece W2. The second holding device 42 is movable between the injection position 84 and the second transport position 82. The second holding device 42 is movable over a second movable range E2 from the second transport position 82 to the injection right end position 84R. The second holding device 42 cannot move to the first transport position 80.

The first implantation position for irradiating the first workpiece W1 held by the first holding device 40 with an ion beam is common to the second implantation position for irradiating the second workpiece W2 held by the second holding device 42 with an ion beam. That is, the first implantation position and the second implantation position coincide with the common implantation position 84. Furthermore, the first movement range in which the first holding device 40 reciprocates the first workpiece W1 at the first implantation position is common to the second movement range in which the second holding device 42 reciprocates the second workpiece W2 at the second implantation position. That is, the first movement range and the second movement range coincide with the common movement range C. The first movement range and the second movement range overlap when viewed in the direction of beam propagation. The vertical position of the first workpiece W1 held by the first holding device 40 at the first implantation position is common to the vertical position of the second workpiece W2 held by the second holding device 42 at the second implantation position. The position in the beam propagation direction of the first workpiece W1 held by the first holding device 40 at the first implantation position is the same as the position in the beam propagation direction of the second workpiece W2 held by the second holding device 42 at the second implantation position. Therefore, the first holding device 40 and the second holding device 42 are configured to allow the first workpiece W1 and the second workpiece W2 to move back and forth in the same manner relative to the scan beam SB. Therefore, the first workpiece W1 and the second workpiece W2 are irradiated with the scan beam SB in a common implantation environment.

Figures 4(a) and (b) are top views schematically showing the horizontal orientation of the first workpiece W1 held by the first holding device 40. Figures 4(a) and (b) show the change in the horizontal orientation of the first workpiece W1 caused by the first horizontal angle adjustment mechanism 56. The same applies to the horizontal orientation of the second workpiece W2 held by the second holding device 42.

Figures 4(a) and (b) show the orientation of the first workpiece W1 during the implantation process in which the scan beam SB is irradiated onto the first workpiece W1. Figure 4(a) shows the case where the surface to be processed of the first workpiece W1 is perpendicular to the direction of travel of the scan beam SB (z3 direction). Figure 4(b) shows the case where the surface to be processed of the first workpiece W1 intersects the direction of travel of the scan beam SB (z3 direction) obliquely. In Figure 4(b), the surface to be processed of the first workpiece W1 has a horizontal tilt angle α1 with respect to the direction of travel of the scan beam SB (z3 direction). The horizontal tilt angle α1 indicates the horizontal inclination of the incident direction of the scan beam SB with respect to the normal to the surface to be processed of the first workpiece W1. The first holding device 40 can adjust the horizontal tilt angle α1 of the first workpiece W1 by driving the first horizontal angle adjustment mechanism 56 to adjust the horizontal rotation angle φc1. The first holding device 40 is configured to be able to adjust the horizontal tilt angle α1 within a range of, for example, ±30 degrees or ±60 degrees during ion implantation.

Figures 5(a) to 5(c) are side views that schematically show the vertical orientation of the first workpiece W1 held by the first holding device 40. Figures 5(a) to 5(c) show changes in the vertical orientation of the first workpiece W1 caused by the first vertical angle adjustment mechanism 54. The same applies to the vertical orientation of the second workpiece W2 held by the second holding device 42.

Figure 5(a) shows an example of the orientation of the first workpiece W1 during the injection process in which the scan beam SB is irradiated onto the first workpiece W1. In Figure 5(a), the first holding device 40 holds the first workpiece W1 so that the surface to be processed of the first workpiece W1 is oriented perpendicular to the direction of travel of the scan beam SB (direction z3). In other words, the first holding device 40 holds the first workpiece W1 so that the surface to be processed of the first workpiece W1 is oriented not along the horizontal direction. In the example of Figure 5(a), the first holding device 40 holds the first workpiece W1 so that the surface to be processed of the first workpiece W1 is oriented along the vertical direction.

Figure 5(b) shows another example of the orientation of the first workpiece W1 during the injection process in which the scan beam SB is irradiated onto the first workpiece W1. In Figure 5(b), the first holding device 40 holds the first workpiece W1 so that the surface to be processed of the first workpiece W1 is inclined relative to the vertical direction. In Figure 5(b), the first holding device 40 holds the first workpiece W1 so that the surface to be processed of the first workpiece W1 is not aligned with the horizontal direction. In Figure 5(b), the surface to be processed of the first workpiece W1 has a vertical tilt angle β1 with respect to the direction of travel of the scan beam SB (direction z3). The vertical tilt angle β1 indicates the vertical inclination of the incident direction of the scan beam SB with respect to the normal to the surface to be processed of the first workpiece W1. The first holding device 40 can adjust the vertical tilt angle β1 by driving the first vertical angle adjustment mechanism 54 to adjust the vertical rotation angle φb1. The first holding device 40 is configured to be able to adjust the vertical tilt angle β1 within a range of ±30 degrees or ±60 degrees, for example, during ion implantation.

Figure 5(c) shows the orientation of the first workpiece W1 during the transport process in which the first workpiece W1 is loaded into or unloaded from the first holding device 40. In Figure 5(c), the first holding device 40 holds the first workpiece W1 with the processing surface of the first workpiece W1 oriented horizontally. In Figure 5(c), the first holding device 40 lifts the first workpiece W1 using the first lift mechanism 50a so that the first workpiece W1 moves away from the first chuck mechanism 50. This allows the arm of the first transport robot for loading or unloading the first workpiece W1 to be inserted into the gap 50b between the first chuck mechanism 50 and the first workpiece W1. Note that it is not necessary for the arm of the first transport robot to be inserted into the gap 50b between the first chuck mechanism 50 and the first workpiece W1. The arm of the first transport robot may be configured to support the outer periphery of the first workpiece W1 rather than the back surface of the first workpiece W1. In this case, the gap 50b may be very small.

FIGS. 6 to 9 are front views showing an example of the operation of the first holding device 40 and the second holding device 42. FIG. 6 shows a situation in which the first injection process is being performed on the first workpiece W1. In FIG. 6, the first holding device 40 is positioned at the injection position 84, and the second holding device 42 is positioned at the second transfer position 82. The first holding device 40 reciprocates horizontally at the injection position 84 as indicated by the arrow X to perform the injection process on the first workpiece W1. The second holding device 42 lifts up the second workpiece W2 using the second lift mechanism 60a at the second transfer position 82 in order to transport the second workpiece W2 after the injection process through the second transfer port 76. The second holding device 42 receives the second workpiece W2 using the second lift mechanism 60a at the second transfer position 82 in order to transport the second workpiece W2 before the injection process through the second transfer port 76.

6, the first holding device 40 holds the first workpiece W1 so that the scan beam SB is irradiated onto the processing surface of the first workpiece W1. The first holding device 40 holds the first workpiece W1 in an orientation where the horizontal tilt angle α1 is 0, as shown in FIG. 4(a), for example. The first holding device 40 holds the first workpiece W1 in an orientation where the vertical tilt angle β1 is 0, as shown in FIG. 5(a), for example. The first holding device 40 may hold the first workpiece W1 in an orientation where the horizontal tilt angle α1 is not 0, as shown in FIG. 4(b). The first holding device 40 may hold the first workpiece W1 in an orientation where the vertical tilt angle β1 is not 0, as shown in FIG. 5(b). The first holding device 40 may hold the first workpiece W1 in an orientation where both the horizontal tilt angle α1 and the vertical tilt angle β1 are not 0.

In Figure 6, the second holding device 42 holds the second workpiece W2 in an orientation that allows the second workpiece W2 to be loaded or unloaded through the second transport port 76. As in Figure 5 (c), the second holding device 42 holds the second workpiece W2 with the processing surface of the second workpiece W2 oriented horizontally. The second holding device 42 lifts up the second workpiece W2 using the second lift mechanism 60a, forming a gap 60b between the second chuck mechanism 60 and the second workpiece W2. The second transport device 72 loads the second workpiece W2 after the injection process by inserting the arm of the second transport robot into the gap 60b between the second chuck mechanism 60 and the second workpiece W2. When the second workpiece W2 before injection processing is placed on the second lift mechanism 60a by the arm of the second transport robot, the second holding device 42 releases the lift-up of the second workpiece W2 and holds the second workpiece W2 in the second chuck mechanism 60. After holding the second workpiece W2 before injection processing, the second holding device 42 drives the second vertical angle adjustment mechanism 64 to change the vertical rotation angle φb2 and hold the second workpiece W2 with the processing surface of the second workpiece W2 oriented not along the horizontal direction.

Figure 7 shows the situation when switching from the first injection process into the first workpiece W1 to the second injection process into the second workpiece W2. That is, it shows the situation when the first injection process into the first workpiece W1 ends and the second injection process into the second workpiece W2 begins. In Figure 7, the first holding device 40 moves from the injection position 84 toward the first transfer position 80 as indicated by arrow F1, and the second holding device 42 moves from the second transfer position 82 toward the injection position 84 as indicated by arrow F2. As shown in Figure 7, by moving the first holding device 40 and the second holding device 42 simultaneously in the same direction, the time required to switch from the first injection process to the second injection process can be shortened.

7, the first holding device 40 and the second holding device 42 can be moved so as to maintain the relative distance d between the first workpiece W1 held by the first holding device 40 and the second workpiece W2 held by the second holding device 42. For example, the relative distance d can be maintained constant by making the movement speeds of the first holding device 40 and the second holding device 42 the same. The movement speeds of the first holding device 40 and the second holding device 42 can also be adjusted to move the first holding device 40 and the second holding device 42 so that the relative distance d is maintained within a range from a predetermined upper limit to a predetermined lower limit. In this case, the movement speed of the first holding device 40 may be faster or slower than the movement speed of the second holding device 42. For ion implantation that achieves a uniform dose distribution in the horizontal direction for the workpiece, it is preferable that the relative distance d be as small as possible. For ion implantation that achieves a non-uniform dose distribution in the horizontal direction for the workpiece, it is preferable that the relative distance d be larger than the size of the scan beam SB in the horizontal direction (x3 direction).

In FIG. 7, the movement speed of the first holding device 40 holding the first workpiece W1 at the end of the injection process may be the maximum speed possible for the first holding device 40. By moving the first holding device 40 at the maximum speed, the time required from the completion of the first injection process into the first workpiece W1 to the removal of the first workpiece W1 can be shortened, improving productivity. On the other hand, the movement speed of the second holding device 42 holding the second workpiece W2 at the start of the injection process may be determined according to the injection conditions for the second workpiece W2. By moving the second holding device 42 at a movement speed according to the injection conditions, the second injection process into the second workpiece W2 can be started at the same movement speed after the second workpiece W2 has moved to the injection position 84. This allows the second injection process to be started earlier, improving productivity.

Figure 8 shows the situation when the second injection process is being performed on the second workpiece W2. In Figure 8, the second holding device 42 is positioned at the injection position 84, and the first holding device 40 is positioned at the first transfer position 80. The second holding device 42 reciprocates horizontally at the injection position 84 as indicated by the arrow X to inject the second workpiece W2. The first holding device 40 lifts up the first workpiece W1 using the first lift mechanism 50a at the first transfer position 80 in order to transport the first workpiece W1 after the injection process through the first transfer opening 74. The first holding device 40 receives the first workpiece W1 using the first lift mechanism 50a at the first transfer position 80 in order to transport the first workpiece W1 before the injection process through the first transfer opening 74.

In FIG. 8, the second holding device 42 holds the second workpiece W2 so that the scan beam SB is irradiated onto the processing surface of the second workpiece W2. The second holding device 42 holds the second workpiece W2 in an orientation where the horizontal tilt angle α2 is 0, as in FIG. 4(a), for example. The second holding device 42 holds the second workpiece W2 in an orientation where the vertical tilt angle β2 is 0, as in FIG. 5(a), for example. The second holding device 42 may hold the second workpiece W2 in an orientation where the horizontal tilt angle α2 is not 0, as in FIG. 4(b). The second holding device 42 may hold the second workpiece W2 in an orientation where the vertical tilt angle β2 is not 0, as in FIG. 5(b). The second holding device 42 may hold the second workpiece W2 in an orientation where both the horizontal tilt angle α2 and the vertical tilt angle β2 are not 0.

In Figure 8, the first holding device 40 holds the first workpiece W1 so that it is oriented in a way that allows the first workpiece W1 to be loaded or unloaded through the first transport port 74. As shown in Figure 5 (c), the first holding device 40 holds the first workpiece W1 so that the processing surface of the first workpiece W1 is oriented horizontally. The first holding device 40 lifts up the first workpiece W1 using the first lift mechanism 50a, forming a gap 50b between the first chuck mechanism 50 and the first workpiece W1. The first transport device 70 loads the first workpiece W1 after the injection process by inserting the arm of the first transport robot into the gap 50b between the first chuck mechanism 50 and the first workpiece W1. When the first workpiece W1 before injection processing is placed on the first lift mechanism 50a by the arm of the first transport robot, the first holding device 40 releases the lift-up of the first workpiece W1 and holds the first workpiece W1 in the first chuck mechanism 50. After holding the first workpiece W1 before injection processing, the first holding device 40 drives the first vertical angle adjustment mechanism 54 to change the vertical rotation angle φb1 and holds the first workpiece W1 with the processing surface of the first workpiece W1 oriented not along the horizontal direction.

Figure 9 shows the situation when switching from the second injection process into the second workpiece W2 to the first injection process into the first workpiece W1. That is, it shows the situation when the second injection process into the second workpiece W2 ends and the first injection process into the first workpiece W1 begins. In Figure 9, the first holding device 40 moves from the first transfer position 80 toward the injection position 84 as shown by arrow F3, and the second holding device 42 moves from the injection position 84 toward the second transfer position 82 as shown by arrow F4. As shown in Figure 9, by moving the first holding device 40 and the second holding device 42 simultaneously in the same direction, the time required to switch from the second injection process to the first injection process can be shortened.

In FIG. 9, the first holding device 40 and the second holding device 42 can be moved so as to maintain the relative distance d between the first workpiece W1 held by the first holding device 40 and the second workpiece W2 held by the second holding device 42. For example, the relative distance d can be maintained constant by making the movement speeds of the first holding device 40 and the second holding device 42 the same. Note that the movement speeds of the first holding device 40 and the second holding device 42 can also be adjusted to move the first holding device 40 and the second holding device 42 so that the relative distance d is maintained within a range from a predetermined upper limit to a predetermined lower limit. In this case, the movement speed of the first holding device 40 may be faster or slower than the movement speed of the second holding device 42. It is preferable that the relative distance d be greater than the horizontal size (x3 direction) of the scan beam SB.

In FIG. 9, the movement speed of the second holding device 42 holding the second workpiece W2 at the end of the injection process may be the maximum speed that the second holding device 42 can achieve. By moving the second holding device 42 at the maximum speed, the time required from the completion of the second injection process into the second workpiece W2 to the removal of the second workpiece W2 can be shortened, improving productivity. On the other hand, the movement speed of the first holding device 40 holding the first workpiece W1 at the start of the injection process may be determined according to the injection conditions of the first workpiece W1. By moving the first holding device 40 at a movement speed according to the injection conditions, the first injection process into the first workpiece W1 can be started at the same movement speed after the first workpiece W1 has moved to the injection position 84. This allows the start of the first injection process to be accelerated, improving productivity.

FIG. 10 is a flowchart showing the flow of an ion implantation method according to an embodiment. First, a first workpiece W1 before implantation is loaded into the first holding device 40 (S10). In S10, the first workpiece W1 held in the first holding device 40 and having been implanted may be unloaded, and then the first workpiece W1 before implantation may be loaded into the first holding device 40. Next, the second holding device 42 is moved to the second transfer position 82 (S12), and the first holding device 40 is moved to the first implantation position (e.g., implantation position 84) (S14). S12 and S14 can be performed simultaneously, and can be performed so that the execution periods of S12 and S14 at least partially overlap. Next, the first holding device 40 is moved back and forth at the first implantation position, and the reciprocating first workpiece W1 is irradiated with an ion beam (S16).

Before, during, or after S16, the second workpiece W2 before the implantation process is loaded into the second holding device 42 (S18). In S18, the implanted second workpiece W2 held in the second holding device 42 may be unloaded, and then the second workpiece W2 before the implantation process may be loaded into the second holding device 42. Next, the first holding device 40 is moved to the first transfer position 80 (S20), and the second holding device 42 is moved to a second implantation position (e.g., implantation position 84) (S22). S20 and S22 can be performed simultaneously, and can be performed so that the respective execution periods of S20 and S22 at least partially overlap. Next, the second holding device 42 is moved back and forth at the second implantation position, and the reciprocating second workpiece W2 is irradiated with an ion beam (S24).

The flow shown in FIG. 10 can be executed repeatedly. For example, the processing of S10 after the repetition can be executed before, during, or after the execution of S24. Before, during, or after the execution of S24, the first workpiece W1 held in the first holding device 40 that has been injected can be removed, and the first workpiece W1 before the injection can be carried into the first holding device 40. By repeating the flow shown in FIG. 10, the first injection process into the first workpiece W1 held in the first holding device 40 and the second injection process into the second workpiece W2 held in the second holding device 42 can be executed alternately and repeatedly. The flow shown in FIG. 10 can be executed repeatedly until the injection processes for the multiple workpieces to be processed consecutively are completed.

In this embodiment, by providing multiple holding devices in the injection processing chamber 14, the injection process and transport process for the workpieces can be carried out in parallel. For example, the transport process for the second workpiece W2 can be carried out by the second holding device 42 simultaneously with the first injection process for the first workpiece W1 held by the first holding device 40. Furthermore, the transport process for the first workpiece W1 can be carried out by the first holding device 40 simultaneously with the second injection process for the second workpiece W2 held by the second holding device 42. As a result, the time required for continuous processing of multiple workpieces can be shortened and productivity can be improved compared to when the injection process and transport process are carried out alternately using a single holding device.

According to this embodiment, by configuring multiple holding devices to reciprocate horizontally, the configuration of the implantation processing chamber 14 and the transfer device 16 can be made less complex than in a configuration in which multiple holding devices reciprocate vertically. Furthermore, by configuring multiple holding devices to reciprocate horizontally, the vertical size of the implantation processing chamber 14 and the transfer device 16 can be reduced. As a result, it is possible to provide an ion implantation device 10 having an external size that falls within the height restrictions on the floor of a typical semiconductor process factory.

In this embodiment, by configuring multiple holding devices to move along a common guide rail 44, the reciprocating movements of the multiple holding devices at the injection position can be standardized. As a result, differences in the injection environment caused by using multiple holding devices can be prevented. As a result, it is possible to improve the productivity of injection processing for multiple workpieces while suppressing variations in the injection processing for multiple workpieces.

In this embodiment, by scanning the ion beam back and forth in the vertical direction and moving the workpiece back and forth in the horizontal direction, the entire surface of the workpiece can be efficiently irradiated with the scan beam. Furthermore, by deflecting the ion beam horizontally in the mass analysis unit 24 and the energy analysis unit 34, a beamline A can be formed that travels along a horizontal plane, thereby reducing the vertical size of the beam generation device 12.

In this embodiment, by making the front slit 20c of the ion source 20 a slit-like shape that is long in the horizontal direction, an ion beam that spreads in the horizontal direction can be generated through the extraction section 22. As a result, it is easier to generate an ion beam with a larger beam current than when a spot-shaped ion beam is extracted from the ion source 20. Furthermore, because the vertical size of the ion beam extracted from the ion source 20 is small, the distance between the opposing magnetic poles of the mass analysis magnet device 24a through which the ion beam passes can be made smaller. As a result, the size of the mass analysis magnet device 24a can be reduced. For example, compared to a comparative example in which the front slit of the ion source is narrowed in the horizontal direction and has a slit-like shape that is long in the vertical direction, an ion beam with a larger beam current can be generated while keeping the size of the mass analysis magnet device 24a smaller.

According to this embodiment, by shaping the horizontally expanding ion beam into a spot shape using the beam shaping unit 26, a spot beam suitable for vertical beam scanning by the beam scanning unit 28 can be formed. By scanning the spot beam vertically using the beam scanning unit 28, ion implantation into workpieces with large vertical dimensions becomes possible. According to this embodiment, a scan beam with a larger beam current can be irradiated onto workpieces with large vertical dimensions, thereby improving the productivity of the implantation process.

In this embodiment, the direction of application of magnetic field B1 in the ion source 20 and the direction of application of magnetic field B2 in the mass analysis unit 24 are perpendicular to each other, which increases the possibility of interference between the two adversely affecting beam quality and magnetic field control. On the other hand, in the comparative example in which the direction of application of the magnetic field in the ion source is vertical, the direction of application of the magnetic field in the ion source and the direction of application of the magnetic field in the mass analysis unit are parallel, so even if the two magnetic fields interfere to some extent, it does not pose a major problem. According to this embodiment, by providing a magnetic shield 23 between the extraction unit 22 and the mass analysis unit 24, magnetic field interference between the horizontal magnetic field B1 applied to the ion source 20 and the vertical magnetic field B2 applied to the mass analysis unit 24 can be suppressed. This makes it possible to achieve both high plasma generation efficiency in the ion source 20 and high mass analysis accuracy in the mass analysis unit 24.

This embodiment can be applied to ion implantation processing of workpieces that are large in size in the vertical direction. One example of a workpiece that is large in size in the vertical direction is a large substrate used in the manufacture of flat panel displays (FPDs). The vertical and horizontal dimensions of such a large substrate are, for example, 1 m x 2 m or more. It is not realistic to move such a large workpiece back and forth in the vertical direction. According to this embodiment, the workpiece is moved back and forth in the horizontal direction, which makes it easier to move the large substrate back and forth compared to moving the workpiece back and forth in the vertical direction. Ion implantation processing can be performed on the large substrate by irradiating a scan beam that is scanned vertically onto the large substrate that is moving back and forth in the horizontal direction.

When the workpiece is a large substrate for an FPD, the ion implantation apparatus 10 does not need to include at least one of the beam collimator 30, the acceleration/deceleration unit 32, and the energy analyzer 34. When the workpiece is a large substrate for an FPD, the implantation chamber 14 may be loaded and unloaded by moving the workpiece horizontally. For example, the large substrate before implantation may be loaded into the right (or left) side of the implantation chamber 14, moved left (or right) within the implantation chamber 14 to perform ion implantation, and the large substrate after implantation may be unloaded from the left (or right) side of the implantation chamber 14. In this way, the ion implantation apparatus 10 may continuously process large substrates in-line.

FIG. 11 is a flowchart showing the flow of an ion implantation method according to a modified example. In the flow of FIG. 11, a first implantation process for a first workpiece W1 and a second implantation process for a second workpiece W2 are carried out in parallel.

First, the first workpiece W1 before injection processing is carried into the first holding device 40 (S30). In S30, the first workpiece W1 after injection processing held in the first holding device 40 may be carried out, and then the first workpiece W1 before injection processing may be carried into the first holding device 40. Alternatively, the second workpiece W2 before injection processing is carried into the second holding device 42 (S32). In S32, the second workpiece W2 after injection processing held in the second holding device 42 may be carried out, and then the second workpiece W2 before injection processing may be carried into the second holding device 42. The order of steps S30 and S32 does not matter; S32 may be started after S30 starts, or S30 may be started after S32 starts. Steps S30 and S32 may be performed simultaneously.

Next, the first holding device 40 is moved to a first injection position (e.g., injection position 84) (S34). The first holding device 40 is moved back and forth at the first injection position, thereby irradiating the reciprocating first workpiece W1 with an ion beam (S36). The number of reciprocating movements of the first workpiece W1 in S36 is not particularly limited, but may be, for example, only one reciprocation. Thereafter, the first holding device 40 is retracted from the first injection position (S38), and the second holding device 42 is moved to a second injection position (e.g., injection position 84) (S40). The first retraction position to which the first holding device 40 is retracted is, for example, located between the first transfer position 80 and the first injection position. The first retraction position to which the first holding device 40 is retracted may be the same as the first transfer position 80.

Next, the second holding device 42 is moved back and forth at the second implantation position, thereby irradiating the reciprocating second workpiece W2 with an ion beam (S42). The number of reciprocating movements of the second workpiece W2 in S42 is not particularly limited, but may be, for example, only one reciprocation. Thereafter, the second holding device 42 is retracted from the second implantation position (S44). The second retraction position to which the second holding device 42 is retracted is, for example, located between the second transfer position 82 and the second implantation position. The second retraction position to which the second holding device 42 is retracted may be the same as the second transfer position 82.

If the implantation process for the first workpiece W1 and the second workpiece W2 is not complete (N in S46), steps S34 to S44 are repeated until the implantation process is complete. For example, if the number of reciprocating movements required to complete the implantation process for the first workpiece W1 and the second workpiece W2 is three (i.e., three round trips), steps S34 to S44 are repeated three times. In this case, the process of irradiating the ion beam by making one round trip of the first workpiece W1 and the process of irradiating the ion beam by making one round trip of the second workpiece W2 are alternately performed three times each. In this case, S38 and S40 can be performed simultaneously by minimizing the relative distance d between the first workpiece W1 and the second workpiece W2, and S44 and S34 can be performed simultaneously by minimizing the relative distance d between the first workpiece W1 and the second workpiece W2. In other words, the relative distance d between the first workpiece W1 and the second workpiece W2 can be kept as small as possible, and the first workpiece W1 and the second workpiece W2 can be moved back and forth in the same direction in synchronization. This improves the efficiency of ion beam utilization.

If the injection process is completed in S46 (Y in S46), the first holding device 40 is moved to the first transfer position 80 (S48), and the second holding device 42 is moved to the second transfer position 82 (S50). The order of steps S48 and S50 does not matter; S50 may be started after S48, or S48 may be started after S50. Steps S48 and S50 may be executed simultaneously. Furthermore, if the first retraction position is the first transfer position 80, step S48 may be omitted because the first holding device 40 is already positioned at the first transfer position 80 in step S38. Similarly, if the second retraction position is the second transfer position 82, step S50 may be omitted because the second holding device 42 is already positioned at the second transfer position 82 in step S44.

The flow shown in FIG. 11 can be repeatedly executed until the implantation process for multiple workpieces to be processed consecutively is completed. According to the flow shown in FIG. 11, the first transport process of loading and unloading the first workpiece W1 using the first holding device 40 and the second transport process of loading and unloading the second workpiece W2 using the second holding device 42 can be executed simultaneously, thereby improving productivity. The flow shown in FIG. 11 is preferably applied when the implantation time during which the workpiece is irradiated with an ion beam is sufficiently short (e.g., less than half) compared to the transport time required for loading and unloading the workpiece. The flow shown in FIG. 11 is also preferably applied when the implantation time during which the workpiece is irradiated with an ion beam is sufficiently long (e.g., more than twice) compared to the transport time required for loading and unloading the workpiece. The flow shown in FIG. 11 can also be applied when the implantation time during which the workpiece is irradiated with an ion beam is approximately the same as the transport time required for loading and unloading the workpiece; in this case, the flow shown in FIG. 10 may be more productive.

In the above-described embodiment, the beam generating device 12 generates a scanned beam using the beam scanning unit 28 and the beam collimating unit 30. In another embodiment, the beam generating device may generate a ribbon beam. The beam generating device may include a ribbon beam generating unit instead of the beam scanning unit 28. The ribbon beam generating unit generates a ribbon beam by diverging a spot-shaped ion beam in the vertical direction. The ribbon beam generating unit may be configured with an electric field type or magnetic field type beam diverging device.

In the above-described embodiment, the ion beam extracted from the ion source 20 is a ribbon-shaped beam that expands in the horizontal direction. In another embodiment, the ion beam extracted from the ion source may be a ribbon beam that expands in the vertical direction. In this case, the front slit of the ion source has a slit shape with a long vertical opening width and a short horizontal opening width. Similarly, the extraction electrode of the extraction unit has a slit shape with a long vertical opening width and a short horizontal opening width. In this case, the mass analysis unit is configured to deflect the vertically expanded ribbon beam in the horizontal direction. In this case, the beam generation device does not need to include the beam scanning unit 28 and the beam collimator 30. In this case, the ion source and extraction unit can be said to be a ribbon beam generation unit for generating a vertically expanded ribbon beam.

In the other embodiment described above, the size of the vertical irradiation range of the ribbon beam expanded in the vertical direction is larger than the vertical size of the workpiece. Therefore, the beam generating device that generates the ribbon beam is configured to irradiate the ion beam over an irradiation range whose size in the vertical direction is larger than the size of the workpiece's surface to be processed. Note that in the embodiment described above, the beam generating device 12 that generates the scan beam is configured to irradiate the ion beam over an irradiation range whose size in the vertical direction is larger than the size of the workpiece's surface to be processed.

In the above-described embodiment, the implantation processing chamber 14 is provided with multiple holding devices 40, 42. In another embodiment, the implantation processing chamber 14 may be provided with only a single holding device. The single holding device may be configured similarly to either the first holding device 40 or the second holding device 42 described above.

In the above-described embodiment, the scanning direction of the scan beam SB is vertical. In another embodiment, the scanning direction of the scan beam SB may be configured to be inclined relative to the vertical. In this case, the beam scanning unit 28, beam collimation unit 30, acceleration/deceleration unit 32, and energy analysis unit 34 are arranged at a position rotated (i.e., in an inclined orientation) around the beam line A extending in the z2 direction as the axis of rotation (for example, at a position downstream of the mass analysis unit 24 and upstream of the beam scanning unit 28). Note that it is also possible to arrange it so that only the beam scanning unit 28 and the beam collimation unit 30 rotate, and at least one of the acceleration/deceleration unit 32 and the energy analysis unit 34 does not rotate. In this case, it is preferable that the scanning direction of the scan beam SB is within 45 degrees of the vertical.

In the above-described embodiment, the first holding device 40 and the second holding device 42 move horizontally. In another embodiment, the movement direction of the first holding device 40 and the second holding device 42 does not have to be horizontal, and may be inclined relative to the horizontal. The movement direction of the first holding device 40 and the second holding device 42 may be a direction other than the horizontal direction and may be any direction that crosses the scan beam.

Some aspects of the present disclosure are as follows.
(Item 1) an ion source for generating ions;
an extractor that extracts the ions from the ion source to generate an ion beam;
a beam scanning unit configured to reciprocally scan the ion beam in a scan direction different from a horizontal direction to generate a scanned beam;
An ion implantation apparatus comprising: a holding device configured to be able to hold a workpiece, the holding device configured to reciprocate the workpiece held by the holding device in a direction crossing the scan beam.
(Item 2) The ion implantation apparatus according to Item 1, wherein the holding device is configured to reciprocate the object held by the holding device in the horizontal direction.
(Item 3) The ion implantation apparatus according to item 1 or 2, wherein the scanning direction is a direction within 45 degrees from the vertical direction.
(Item 4) The ion implantation apparatus according to item 1 or 2, wherein the scanning direction is a vertical direction.
(Item 5) The ion source includes a front slit through which the ions extracted by the extraction unit pass,
5. The ion implantation apparatus according to any one of items 1 to 4, wherein the horizontal opening width of the front slit is larger than the vertical opening width of the front slit.
(Item 6) The ion source is
an arc chamber having an internal space and a front slit for extracting the ions from plasma generated in the internal space;
Item 6. The ion implantation apparatus according to item 5, further comprising: a magnet device that applies the horizontal magnetic field to the internal space.
(Item 7) The extraction section includes an extraction electrode having an extraction opening through which the ion beam passes,
Item 7. The ion implantation apparatus according to item 5 or 6, wherein the extraction opening has a width in the horizontal direction greater than a width in the vertical direction of the extraction opening.
(Item 8) The ion implantation apparatus according to any one of items 1 to 7, further comprising a mass analysis unit provided between the extraction unit and the beam scanning unit, for deflecting the ion beam in the horizontal direction.
(Item 9) The ion implantation apparatus according to Item 8, wherein the mass analysis section includes a magnet device that applies a magnetic field to the ion beam in a vertical direction.
(Item 10) The ion implantation apparatus according to item 8 or 9, further comprising a magnetic shield provided between the extraction section and the mass analysis section, the magnetic shield having a passage opening through which the ion beam passes.
(Item 11) An ion implantation apparatus according to any one of Items 8 to 10, further comprising a beam shaping unit provided between the mass analysis unit and the beam scanning unit, the beam shaping unit comprising at least one lens device for adjusting at least one of the cross-sectional shape and convergence/divergence angle of the ion beam.
(Item 12) The ion implantation apparatus according to any one of Items 1 to 11, further comprising a beam collimator provided downstream of the beam scanning unit to collimate the scan beam.
(Item 13) An ion implantation apparatus according to any one of items 1 to 12, further comprising an energy analysis unit including a deflection device that deflects the scan beam in the horizontal direction and an energy analysis slit provided downstream of the deflection device.
(Item 14) The ion implantation apparatus according to Item 13, wherein the deflection device comprises a pair of electrodes facing each other across the scan beam, and a power supply that applies a DC voltage to the pair of electrodes.
(Item 15) The ion implantation apparatus according to Item 14, wherein the electrode pair of the deflection device is arranged to face each other in the horizontal direction.
(Item 16) The ion implantation apparatus according to Item 14, wherein the electrode pair of the deflection device is arranged to face each other in a direction perpendicular to the scanning direction.
(Item 17) generating ions using an ion source;
extracting the ions from the ion source to form an ion beam;
generating a scanned beam by scanning the ion beam back and forth in a scan direction different from a horizontal direction;
and moving the workpiece back and forth in a direction crossing the scan beam.

Some aspects of the present disclosure are as follows.
(Item 18) A beam generating device configured to generate an ion beam to be irradiated onto a workpiece, and to irradiate the ion beam over an irradiation range whose size in the vertical direction is larger than the size of the surface to be processed of the workpiece;
a first holding device configured to be able to hold a first workpiece, the first holding device configured to reciprocate the first workpiece held by the first holding device in a horizontal direction so that the first workpiece crosses the irradiation range;
An ion implantation apparatus comprising: a second holding device configured to be able to hold a second object to be processed, the second holding device configured to move the second object to and fro in the horizontal direction so that the second object to be processed held by the second holding device crosses the irradiation range.
(Item 19) The first holding device is configured to be movable between a first implantation position for irradiating the first workpiece with the ion beam and a first transport position for carrying the first workpiece into or out of the first holding device,
Item 19. The ion implantation apparatus described in Item 18, wherein the second holding device is configured to be movable between a second implantation position for irradiating the second workpiece with the ion beam and a second transport position for loading or unloading the second workpiece into or from the second holding device.
(Item 20) The ion implantation apparatus according to Item 19, wherein the first implantation position and the second implantation position are located between the first transfer position and the second transfer position.
(Item 21) An ion implantation apparatus described in Item 19 or Item 20, wherein a first movement range in which the first holding device moves the first workpiece back and forth at the first implantation position overlaps with a second movement range in which the second holding device moves the second workpiece back and forth at the second implantation position in the beam propagation direction.
(Item 22) The ion implantation apparatus according to Item 21, wherein the first movement range is common to the second movement range.
(Item 23) An ion implantation apparatus described in any one of Items 19 to 22, wherein the vertical position of the first workpiece held by the first holding device at the first implantation position is the same as the vertical position of the second workpiece held by the second holding device at the second implantation position.
(Item 24) An ion implantation apparatus described in any one of Items 19 to 23, wherein the position in the beam propagation direction of the first workpiece held by the first holding device at the first implantation position is the same as the position in the beam propagation direction of the second workpiece held by the second holding device at the second implantation position.
(Item 25) The first holding device is configured to be unable to move to the second conveying position,
25. The ion implantation apparatus according to any one of items 19 to 24, wherein the second holding device is configured to be unable to move to the first transfer position.
(Item 26) An ion implantation apparatus according to any one of Items 18 to 25, wherein the first holding device and the second holding device are movable in the same direction.
(Item 27) An ion implantation apparatus described in any one of Items 18 to 26, wherein the first holding device and the second holding device are capable of moving simultaneously in the same direction while maintaining the relative distance between the first workpiece held by the first holding device and the second workpiece held by the second holding device.
(Item 28) An ion implantation apparatus according to any one of Items 18 to 27, wherein the first holding device and the second holding device are movable along a common guide rail.
(Item 29) The first holding device includes a first vertical angle adjustment mechanism that adjusts the vertical orientation of the first workpiece, and a first horizontal angle adjustment mechanism that adjusts the horizontal orientation of the first workpiece,
29. The ion implantation apparatus according to any one of items 18 to 28, wherein the second holding device comprises a second vertical angle adjustment mechanism that adjusts the vertical orientation of the second workpiece, and a second horizontal angle adjustment mechanism that adjusts the horizontal orientation of the second workpiece.
(Item 30) The first holding device includes a first vertical angle adjustment mechanism that rotates around the horizontal rotation axis to adjust the orientation of the first workpiece, and a first horizontal angle adjustment mechanism that rotates around the vertical rotation axis to adjust the orientation of the first workpiece,
29. The ion implantation apparatus according to any one of items 18 to 28, wherein the second holding device comprises a second vertical angle adjustment mechanism that rotates around the horizontal rotation axis to adjust the orientation of the second workpiece, and a second horizontal angle adjustment mechanism that rotates around the vertical rotation axis to adjust the orientation of the second workpiece.
(Item 31) The first holding device includes a first vertical angle adjustment mechanism that adjusts the orientation of the first workpiece, and the first vertical angle adjustment mechanism is configured to adjust the orientation of the processing surface of the first workpiece to be along the horizontal direction when the first workpiece is carried in or out, and to adjust the orientation of the processing surface of the first workpiece to be not along the horizontal direction when the first workpiece is irradiated with the ion beam,
29. The ion implantation apparatus according to any one of items 18 to 28, wherein the second holding device is provided with a second vertical angle adjustment mechanism that adjusts the orientation of the second workpiece, and the second vertical angle adjustment mechanism is configured to adjust the orientation of the processing surface of the second workpiece to be along the horizontal direction when the second workpiece is loaded or unloaded, and to adjust the orientation of the processing surface of the second workpiece to be not along the horizontal direction when the ion beam is irradiated onto the second workpiece.
(Item 32) The first holding device includes a first horizontal angle adjustment mechanism that adjusts the horizontal orientation of the first workpiece, and a first twist mechanism that adjusts the twist angle of the first workpiece,
Item 32. An ion implantation apparatus according to any one of items 18 to 31, wherein the second holding device comprises a second horizontal angle adjustment mechanism that adjusts the horizontal orientation of the second workpiece, and a second twist mechanism that adjusts the twist angle of the second workpiece.
(Item 33) An ion implantation apparatus according to any one of Items 18 to 32, wherein the beam generating device includes a beam scanning unit that scans the ion beam back and forth across the irradiation range.
(Item 34) An ion implantation apparatus according to any one of Items 18 to 32, wherein the beam generating device includes a ribbon beam generating unit that generates a ribbon beam having a beam size corresponding to the size of the irradiation range.
(Item 35) generating an ion beam to be irradiated onto a workpiece;
irradiating the ion beam over an irradiation range whose size in a vertical direction is larger than the size of the surface to be processed of the workpiece;
holding the first workpiece in a first holding device;
Using the first holding device, reciprocating the first workpiece in a horizontal direction so that the first workpiece crosses the irradiation range;
holding the second object to be processed in a second holding device;
and using the second holding device, reciprocating the second object in the horizontal direction so that the second object crosses the irradiation range.

FIG. 12 is a top view showing the schematic configuration of an ion implantation apparatus 10A according to another embodiment. FIG. 13 is a side view showing the schematic configuration of an ion implantation apparatus 10A according to another embodiment. The ion implantation apparatus 10A shown in FIGS. 12 and 13 differs from the ion implantation apparatus 10 shown in FIGS. 1 and 2 in that it further includes a beam profiler 46 provided in the implantation processing chamber 14. The following description of the ion implantation apparatus 10A will focus on the differences from the above-mentioned embodiments, and will omit a description of the commonalities as appropriate.

The beam profiler 46 is provided inside the implantation processing chamber 14. The beam profiler 46 is a beam measurement device for measuring the scan beam SB at the surface position of the workpieces W1 and W2. The beam profiler 46 is configured to be movable in the vertical direction (y direction) by the operation of the profiler drive device 47. The beam profiler 46 is retracted from the implantation position where the workpieces W1 and W2 are located during ion implantation, and is inserted into the implantation position when the workpieces W1 and W2 are not at the implantation position.

FIG. 14 is a front view schematically illustrating the movable range of the beam profiler 46, and is obtained by adding the beam profiler 46 to FIG. 3 described above. FIG. 14 shows the beam profiler 46 inserted at the implantation position. The beam profiler 46 is movable in the vertical direction (y direction) as indicated by the arrow H by operation of the profiler driver 47. The beam profiler 46 is configured to be movable, for example, over the size _hB of the vertical irradiation range of the scan beam SB, and is configured to be movable between an upper end position 46a vertically above the scan beam SB and a lower end position 46b vertically below the scan beam SB. When the beam profiler 46 is retracted from the implantation position, the beam profiler 46 is disposed, for example, at the upper end position 46a.

The beam profiler 46 is equipped with a profiler cup, which is a Faraday cup for measuring the beam current of the scan beam SB. The beam profiler 46 measures the beam current while moving in the vertical direction (y direction), thereby measuring the beam current throughout the entire beam scanning range of the scan beam SB. The beam profiler 46 may also be a measurement device that measures the beam current density distribution in the vertical direction (y direction) of the scan beam SB.

Beam profiler 46 may be equipped with an angle measurement device for measuring angular information of scan beam SB. The angle measurement device may be equipped with a first angle measurement device capable of measuring angular information in the horizontal direction (x direction) of scan beam SB, and a second angle measurement device capable of measuring angular information in the vertical direction (y direction) of scan beam SB. Beam profiler 46 may be a measurement device that measures angular information in the x direction and angular information in the y direction, and may measure angular center of gravity, convergence/divergence angles, etc. as angular information.

Below, we will explain angle measurement devices that can be used with the beam profiler 46.

(First embodiment)
Fig. 15 is a cross-sectional view showing a schematic configuration of an angle measurement device 100 according to the first embodiment. The angle measurement device 100 is configured to measure angular information of the scan beam SB in a first direction. Fig. 15 shows a case where the first direction is parallel to the scan direction (y direction), but the direction of the angular information measured by the angle measurement device 100 (i.e., the first direction) is not particularly limited, and the first direction may be oblique to the scan direction.

The angle measurement device 100 includes an entrance surface 104 having an entrance opening 102, an exit surface 108 having an exit opening 106, an electrode assembly 110, a power supply 112, and a current measuring device 114.

The angle measurement device 100 may include a front plate 116 having an incident surface 104. The incident aperture 102 is formed to penetrate the front plate 116. The incident aperture 102 passes a portion of the scan beam SB that is incident on the incident surface 104. The incident aperture 102 has an aperture shape in which the opening width in at least the first direction is short.

The angle measurement device 100 may include a rear plate 118 having an exit surface 108. The rear plate 118 is positioned away from the front plate 116 in the direction of travel of the scan beam SB (i.e., the z direction). The exit aperture 106 is formed to penetrate the rear plate 118. The exit aperture 106 passes a portion of the ion beam that has passed through the entrance aperture 102. Similar to the entrance aperture 102, the exit aperture 106 has an opening shape with a short opening width in at least the first direction. The exit aperture 106 is positioned, for example, so that its position in the x and y directions perpendicular to the direction of travel of the scan beam SB (z direction) coincides with that of the entrance aperture 102.

Figure 16(a) is a plan view showing the schematic configuration of an incident surface 104 having an incident aperture 102, and Figure 16(b) is a plan view showing the schematic configuration of an exit surface 108 having an exit aperture 106. The incident aperture 102 can have a slit shape with a short opening width w1 in a first direction (e.g., the y direction) and a long opening width w2 in a direction perpendicular to the first direction (e.g., the x direction). The incident aperture 102 is, for example, a slit with a slit width direction parallel to the scanning direction of the scan beam SB.

The opening width w1 of the entrance aperture 102 in the slit width direction is, for example, 10 mm or less, 5 mm or less, or 3 mm or less. The opening width w1 of the entrance aperture 102 in the slit width direction is, for example, 0.1 mm or more, 0.5 mm or more, or 1 mm or more. The opening width w2 of the entrance aperture 102 in the slit length direction perpendicular to the first direction is longer than, for example, the beam width of the scan beam SB in the x direction. The opening width w2 of the entrance aperture 102 in the slit length direction is, for example, 10 mm or more, 20 mm or more, or 30 mm or more. The opening width w2 of the entrance aperture 102 in the slit length direction is, for example, 200 mm or less, 150 mm or less, or 100 mm or less.

The exit aperture 106 can have the same shape and size as the entrance aperture 102. The exit aperture 106 is, for example, a slit having a slit width direction parallel to the scanning direction of the scan beam SB. The opening width w3 of the exit aperture 106 in the slit width direction may be the same as the opening width w1 of the entrance aperture 102 in the slit width direction. The opening width w4 of the exit aperture 106 in the slit length direction may be the same as the opening width w2 of the entrance aperture 102 in the slit length direction.

Note that the aperture width w2 of the entrance aperture 102 in a direction perpendicular to the first direction may be shorter than the beam width of the scan beam SB. The aperture width w2 of the entrance aperture 102 in a direction perpendicular to the first direction may be approximately the same as the aperture width w1 of the entrance aperture 102 in the first direction. In this case, the aperture shape of the entrance aperture 102 may be rectangular or circular rather than slit-shaped. Similarly, the aperture width w4 of the exit aperture 106 in a direction perpendicular to the first direction may be shorter than the beam width of the scan beam SB in the direction perpendicular to the first direction. The aperture width w4 of the exit aperture 106 in a direction perpendicular to the first direction may be approximately the same as the aperture width w3 of the exit aperture 106 in the first direction. In this case, the aperture shape of the exit aperture 106 may be rectangular or circular rather than slit-shaped.

Returning to Figure 15, the electrode assembly 110 is disposed between the incident surface 104 and the exit surface 108. The electrode assembly 110 has a first electrode surface 122 and a second electrode surface 124 that face each other in a first direction across the ion beam traveling from the incident aperture 102 to the exit aperture 106. The first electrode surface 122 and the second electrode surface 124 face each other so as to be parallel to each other. The facing distance d between the first electrode surface 122 and the second electrode surface 124 in the first direction is sufficiently larger than the opening widths w1 and w3 in the first direction of the incident aperture 102 and the incident surface 104. Here, "sufficiently large" means large enough not to impede the transport of the ion beam from the incident aperture 102 to the exit aperture 106. The facing distance d between the first electrode surface 122 and the second electrode surface 124 in the first direction is, for example, 5 mm or more, 10 mm or more, or 15 mm or more. The opposing distance d in the first direction between the first electrode surface 122 and the second electrode surface 124 is, for example, 50 mm or less, 30 mm or less, or 20 mm or less.

The electrode assembly 110 may include a first electrode body 126 having a first electrode surface 122 and a second electrode body 128 having a second electrode surface 124. A side plate 120 may be provided around the electrode assembly 110 to surround the first electrode body 126 and the second electrode body 128. The side plate 120 may be configured to extend cylindrically from the front plate 116 toward the back plate 118. The front plate 116, back plate 118, and side plate 120 may form a housing that houses the electrode assembly 110. The front plate 116, back plate 118, and side plate 120 may be grounded and have a ground potential.

The power source 112 applies a voltage to the electrode assembly 110, generating a potential difference ΔV between the first electrode surface 122 and the second electrode surface 124. The power source 112 is a variable voltage source, allowing the potential difference ΔV between the first electrode surface 122 and the second electrode surface 124 to be variable. The power source 112 may include a first power source 130 coupled to the first electrode surface 122 or the first electrode body 126, and a second power source 132 coupled to the second electrode surface 124 or the second electrode body 128. The power source 112 may include only one of the first power source 130 or the second power source 132. In this case, the electrode surface or electrode body to which the first power source 130 or the second power source 132 is not coupled may be grounded and have ground potential.

The power supply 112 applies a voltage such that the potential difference ΔV between the first electrode surface 122 and the second electrode surface 124 is, for example, at most 500 V or more, 1000 V or more, or 2000 V or more. The first power supply 130 and the second power supply 132 are each configured to be able to apply a voltage with an absolute value of, for example, up to 1000 V. For example, by setting the applied voltage of the first power supply 130 to -1000 V and the applied voltage of the second power supply 132 to +1000 V, the potential difference ΔV between the first electrode surface 122 and the second electrode surface 124 can be 2000 V. The power supply 112 changes the applied voltage based on, for example, a command value from the control device 18.

The electrode assembly 110 and power supply 112 function as a deflection device that deflects the ion beam from the entrance aperture 102 toward the exit aperture 106. Figure 15 shows trajectories 151, 152, and 153 of an ion beam deflected by the electric field E caused by the potential difference ΔV between the first electrode surface 122 and the second electrode surface 124. The magnitude of the electric field E can be expressed as E = ΔV/d, using the potential difference ΔV between the first electrode surface 122 and the second electrode surface 124 and the opposing distance d. The trajectory 151 shown by the thick line represents an ion beam that can pass through both the entrance aperture 102 and the exit aperture 106. The trajectories 152 and 153 shown by the thin lines represent ion beams that cannot pass through the exit aperture 106 and are blocked by the exit surface 108 or the back plate 118. The ion beam along trajectory 152 cannot pass through the exit aperture 106 because the angle θy in the first direction is slightly larger than that of the ion beam along trajectory 151. Furthermore, the ion beam along trajectory 153 cannot pass through the exit aperture 106 because the angle θy in the first direction is slightly smaller than that of the ion beam along trajectory 151. Therefore, the ion beams that are extracted from the exit aperture 106 are limited to those whose angle θy in the first direction at the entrance aperture 102 is within a specific range.

The angle θy of the first direction that the ion beam emitted from the exit aperture 106 has at the entrance aperture 102 varies depending on the electric field E, i.e., the potential difference ΔV, between the first electrode surface 122 and the second electrode surface 124. Therefore, by changing the potential difference ΔV between the first electrode surface 122 and the second electrode surface 124, it is possible to change the angle θy of the first direction that the ion beam emitted from the exit aperture 106 has at the entrance aperture 102.

The current measuring device 114 detects the ion beam that has passed through the exit aperture 106 and measures the beam current value. The current measuring device 114 includes a Faraday cup 134 for detecting the ion beam and an ammeter 136 coupled to the Faraday cup 134. The current measuring device 114 may further include a suppression electrode 138 disposed between the exit surface 108 and the Faraday cup 134. The suppression electrode 138 is coupled to a suppression power supply 140 for applying a predetermined suppression voltage. The suppression electrode 138 has a passage opening 142 that allows the ion beam to pass from the exit aperture 106 toward the Faraday cup 134. The passage opening 142 has an opening shape that is sufficiently larger than the exit aperture 106 so as not to obstruct the ion beam traveling from the exit aperture 106 toward the Faraday cup 134. Note that instead of a configuration in which a suppression electric field is applied to suppress the movement of electrons, a configuration in which a suppression magnetic field is applied to suppress the movement of electrons may be employed.

The angle measurement device 100 may further include a measurement control device 144. The measurement control device 144 includes a processor 144a and a memory 144b. The measurement control device 144 controls the overall operation of the angle measurement device 100 in accordance with a predetermined program, for example, by having the processor 144a execute the predetermined program stored in the memory 144b. The measurement control device 144 may be configured, for example, in the same manner as the control device 18 described above. The operation of the angle measurement device 100 may be controlled by the control device 18 in addition to or instead of the measurement control device 144.

The measurement control device 144 outputs a command value for setting the applied voltage of the power supply 112. The measurement control device 144, for example, outputs a command value for applying a variable voltage to the electrode assembly 110, thereby changing the value of the potential difference ΔV between the first electrode surface 122 and the second electrode surface 124 over time. The measurement control device 144 may, for example, output a command value for periodically changing the value of the potential difference ΔV between the first electrode surface 122 and the second electrode surface 124. The measurement control device 144 may output a command value that indicates the time series value of the potential difference ΔV between the first electrode surface 122 and the second electrode surface 124.

The measurement control device 144 acquires the beam current value I measured by the current measuring device 114. The measurement control device 144 calculates angular information of the first direction of the scan beam SB using the value of the potential difference ΔV between the first electrode surface 122 and the second electrode surface 124 based on the command value and the acquired beam current value I. The measurement control device 144 calculates the angle θy in the first direction that the ion beam detected by the current measuring device 114 has at the entrance aperture 102, for example, using the beam energy of the scan beam SB and the value of the potential difference ΔV between the first electrode surface 122 and the second electrode surface 124. The measurement control device 144 calculates the intensity of the angular component of the first direction of the scan beam SB by correlating the calculated angle θy with the acquired beam current value. The measurement control device 144 can calculate the angular distribution of the scan beam SB in the first direction by associating multiple potential difference ΔVi (i = 1 to n) values between the first electrode surface 122 and the second electrode surface 124 with multiple beam current values Ii (i = 1 to n) corresponding to the multiple potential difference ΔVi values.

The measurement control device 144 may change the value of the potential difference ΔV between the first electrode surface 122 and the second electrode surface 124 in accordance with the scan period Ts of the scan beam SB. The measurement control device 144 may fix the potential difference ΔV between the first electrode surface 122 and the second electrode surface 124 at the timing when the scan beam SB is incident on the angle measurement device 100 (specifically, the incident surface 104). In other words, the measurement control device 144 may change the potential difference ΔV between the first electrode surface 122 and the second electrode surface 124 at the timing when the scan beam SB is not incident on the angle measurement device 100 (specifically, the incident surface 104).

Figure 17 is a graph showing an example of the scan voltage waveform Vs(t) of the scan beam SB and the time waveform ΔV(t) of the potential difference in the angle measurement device 100. The vertical axis of the graph is the voltage value V, and the maximum absolute values of the scan voltage Vs and the potential difference ΔV are normalized to Vmax. The scan frequency fs (= 1/Ts) corresponding to the scan period Ts of the scan voltage waveform Vs(t) is, for example, 10 Hz or more or 100 Hz or more, and, for example, 100 kHz or less or 10 kHz or less. An example of the scan frequency fs is 1 kHz.

In Figure 17, the measurement timing tj (for example, j = 1 to 2n) at which the scan beam SB is incident on the angle measurement device 100 is represented by a black circle. In the example of Figure 17, the angle measurement device 100 is positioned at the center of the scan direction (i.e., the y direction) of the scan beam SB, and the scan beam SB is incident on the angle measurement device 100 when the scan voltage Vs = 0. The position of the angle measurement device 100 is not particularly limited, and the angle measurement device 100 may be positioned so that the scan beam SB is incident on the angle measurement device 100 at the timing when the scan voltage Vs becomes a specific value other than 0.

The time waveform ΔV(t) of the potential difference in the angle measurement device 100 changes in stages corresponding to the scan period Ts. The value of the potential difference ΔV(t) is fixed at the measurement timing tj when the scan beam SB is incident on the angle measurement device 100, and is changed at a timing different from the measurement timing tj. In the example of Figure 17, the value of the potential difference ΔV is changed at the timing when the scan voltage Vs = -Vmax. Note that the timing when the value of the potential difference ΔV is changed is not particularly limited, and any timing different from the measurement timing tj can be selected; for example, it may be the timing when the scan voltage Vs = +Vmax.

In the example of Figure 17, the value of the potential difference ΔV is changed every scan period Ts, with 15 voltage levels set from -Vmax to +Vmax. While the example of Figure 17 only shows the process of the potential difference ΔV changing from -Vmax to +Vmax, it may also change conversely from Vmax to -Vmax, or from -Vmax to +Vmax and then from +Vmax to -Vmax. Alternatively, the potential difference ΔV may be repeatedly changed between -Vmax and +Vmax. The time it takes for the potential difference ΔV to change from -Vmax to +Vmax corresponds to half (Td/2) of the deflection period Td over which the potential difference ΔV is changed. In the example of Figure 17, the deflection period Td is 28 times the scan period Ts (i.e., Td = 28 x Ts). Therefore, the deflection frequency fd (= 1/Td) corresponding to the deflection period Td is 1/28 of the scan frequency fs.

The number of voltage value steps set in the time waveform ΔV(t) of the potential difference is not particularly limited, but can be, for example, 10 or more, 15 or more, or 20 or more, or, for example, 100 or less, 50 or less, or 30 or less. Increasing the number of steps can improve measurement accuracy (e.g., angular resolution), but increases the time required for measurement. Therefore, the number of steps in the time waveform ΔV(t) of the potential difference can be set appropriately depending on the required balance between angular resolution and measurement time. Furthermore, instead of changing the value of the potential difference ΔV every scan period Ts, the value of the potential difference ΔV may be changed every half of the scan period Ts. In this case, the time required for measurement can be shortened. Alternatively, the value of the potential difference ΔV may be changed every integer multiple of the scan period Ts (e.g., k·Ts). In this case, the number of measurements of the scan beam SB in one period increases, thereby improving measurement accuracy. The deflection frequency fd can be set, for example, to 1/1000 or more, 1/500 or more, or 1/200 or more of the scan frequency fs, or to 1/10 or less, 1/20 or less, or 1/50 or less of the scan frequency fs. An example of the deflection frequency fd is about 1/100 of the scan frequency fs, for example, about 10 Hz. It is preferable that the deflection frequency fd be set differently from the scan frequency fs.

18(a) is a graph showing an example of the time waveform I(t) of the beam current detected by the angle measurement device 100. FIG. 18(a) corresponds to the time waveform I(t) of the beam current when the time waveform of the potential difference ΔV shown in FIG. 17 is applied. The time waveform I(t) of the beam current is composed of time series values of the pulsed beam current Ij measured at each of multiple measurement timings tj. In the example of FIG. 18(a), the scan beam SB enters the angle measurement device 100 once in a round trip (twice in total) while the value of the potential difference ΔVi (= ΔV(t)) is fixed, so two pulsed beam currents Ij are measured for a specific value of the potential difference ΔVi. Using these two beam current values Ij, for example, by summing or averaging them, the beam current value Ii corresponding to a specific value of the potential difference ΔVi can be obtained. Furthermore, by converting the potential difference ΔVi to an angle θyi, the beam current value Ii corresponding to the angle θyi can be obtained. Figure 18(b) is a graph showing an example of the angular distribution of the scan beam calculated using the time waveform I(t) of the beam current in Figure 18(a); for example, an angular distribution such as that shown by the dashed line 156 can be calculated.

According to this embodiment, angular information in the first direction of the scan beam SB can be obtained with high precision in a short time. The scan beam SB incident on the angle measurement device 100 is scanned back and forth by the beam scanning unit 28 (also called a beam scanning device) located upstream of the angle measurement device 100, so the entire beam can be measured without moving the angle measurement device 100. Furthermore, the deflection period Td required to obtain the angular distribution can be set to 1 second or less or 0.1 seconds or less, so the angular distribution in the first direction of the scan beam SB can be measured in an extremely short time. Furthermore, because the angular resolution can be improved by increasing the number of stages of the potential difference ΔVi, measurement accuracy can be improved compared to conventional configurations in which multiple electrode bodies are arranged to measure the angular distribution.

In the above-described embodiment, the deflection frequency fd is smaller than the scan frequency fs, i.e., the deflection period Td is greater than the scan period Ts. In a modified example, the deflection frequency fd may be greater than the scan frequency fs, or the deflection period Td may be smaller than the scan period Ts. For example, the scan frequency fs may be a small value such as 10 Hz or less, and the deflection frequency fd may be, for example, 10 times or more, 20 times or more, or 50 times or more of the scan frequency fs, or, for example, 1000 times or less, 500 times or less, or 200 times or less. The deflection frequency fd may be, for example, 100 Hz or more, 500 Hz or more, or 1 kHz or more, or, for example, 100 kHz or less, 50 kHz or less, or 10 kHz or less. In this case, multiple beam current values Ii corresponding to multiple potential differences ΔVi can be obtained while the scan beam SB is scanned back and forth or one way. Therefore, even in this case, the angular distribution of the scan beam SB in the first direction can be measured during a scan period Ts of 1 second or less or 0.1 seconds or less. In this case, the deflection frequency fd may be set so as not to be an integer multiple of the scan frequency fs.

In the above embodiment, the scan voltage waveform Vs(t) is a triangular wave, but the shape of the scan voltage waveform Vs(t) is not particularly limited and may be a sine wave, a modulated triangular wave or sine wave, or a waveform that changes in a stepwise manner. Furthermore, in the above embodiment, the time waveform ΔV(t) of the potential difference is shown to change in a stepwise manner, but the shape of the time waveform ΔV(t) of the potential difference is not particularly limited and may be a triangular wave, a sine wave, or a modulated triangular wave or sine wave. The scan voltage waveform Vs(t) and the time waveform ΔV(t) of the potential difference may each be any periodically changing waveform, such as a stepwise waveform, a triangular wave, a sine wave, or a modulated triangular wave or sine wave. The deflection frequency fd of the time waveform ΔV(t) of the potential difference may be set so that it is not an integer multiple of the scan frequency fs of the scan voltage waveform Vs(t), and the scan frequency fs may not be an integer multiple of the deflection frequency fd.

In the above embodiment, the case where the scanned beam SB is the measurement target has been described, but the angle measurement device 100 may also measure an ion beam that is not scanned by a beam scanning device. In this case, in order to measure the entire ion beam that is not scanned, the measurement of the ion beam may be performed in combination with moving the angle measurement device 100 in the scan direction (y direction). Furthermore, the measurement of the scanned beam SB may be performed in combination with moving the angle measurement device 100 in the scan direction (y direction).

Second Embodiment
The angle measurement device according to the second embodiment, like the first embodiment, includes an incident surface, an exit surface, an electrode assembly, a power supply, and a current measuring device. The second embodiment differs from the first embodiment in that multiple incident openings are provided on the incident surface and multiple exit openings are provided on the exit surface. The angle measurement device according to the second embodiment will be described below, focusing on the differences from the first embodiment, and a description of the commonalities will be omitted as appropriate.

Figures 19 and 20 are plan views showing the schematic configuration of an angle measurement device 200 according to the second embodiment. Figure 19 shows an incident surface 204 having multiple incident apertures 202a, 202b, and 202c, viewed from the upstream side in the beam propagation direction (z direction). The multiple incident apertures 202a to 202c are arranged side by side in the direction (x direction) perpendicular to the scanning direction of the scan beam SB in the measurement range D. The x-direction aperture ranges D1, D2, and D3 in which the multiple incident apertures 202a to 202c are provided are set to be continuous with no gaps in the x direction and not overlap in the x direction. The multiple incident apertures 202a to 202c are formed to penetrate a front panel 216 having the incident surface 204.

The multiple incident apertures 202a-202c have a slit shape with short aperture widths w1a, w1b, and w1c in the p direction, which is oblique to the scanning direction (y direction), and long aperture widths w2a, w2b, and w2c in the q direction, which is perpendicular to the p direction. The multiple incident apertures 202a-202c have the same aperture widths w1a-w1c in the slit width direction (i.e., p direction). The multiple incident apertures 202a-202c have the same aperture widths w2a, w2b, and w2c in the slit length direction (q direction) as the multiple incident apertures 202a-202c. In the example of Figure 19, the aperture width w2b in the slit length direction of the second incident aperture 202b located in the center is longer than the aperture widths w2a and w2c in the slit length direction of the first and third incident apertures 202a and 202c located on either side of them.

Figure 20 shows an exit surface 208 having multiple exit apertures 206a, 206b, and 206c, viewed from the downstream side in the beam propagation direction (z direction). The multiple exit apertures 206a-206c can have the same shape and size as the corresponding entrance apertures 202a-202c. The multiple exit apertures 206a-206c are arranged so that their positions in the x and y directions perpendicular to the propagation direction of the scan beam SB coincide with the corresponding entrance apertures 202a-202c. The opening widths w3a, w3b, and w3c in the slit width direction of the multiple exit apertures 206a-206c may be the same as the opening widths w1a-w1c in the slit width direction of the corresponding entrance apertures 202a-202c. The opening widths w4a, w4b, and w4c in the slit length direction of the multiple exit openings 206a to 206c may be the same as the opening widths w2a to w2c in the slit length direction of the corresponding entrance openings 202a to 202c.

In the example shown in Figures 19 and 20, the angle measurement device 200 has three entrance openings 202a-202c and three exit openings 206a-206c. That is, the angle measurement device 200 has a first entrance opening 202a, a second entrance opening 202b, and a third entrance opening 202c provided on the entrance surface 204, and a first exit opening 206a, a second exit opening 206b, and a third exit opening 206c provided on the exit surface 208. Note that the number of each of the multiple entrance openings and multiple exit openings provided in the angle measurement device 200 is not limited to three, and may be two, or four or more.

In the example shown in Figures 19 and 20, the angle θ1 between the slit width direction (p direction) and the scanning direction (y direction) of the multiple entrance apertures 202a-202c and the multiple exit apertures 206a-206c is 45 degrees. Note that the angle θ1 between the slit width direction (p direction) and the scanning direction (y direction) is not particularly limited, and may be, for example, 5 degrees or more, 15 degrees or more, or 30 degrees or more, or may be, for example, 85 degrees or less, 75 degrees or less, or 60 degrees or less.

Figure 21 is a cross-sectional view showing the schematic configuration of an electrode assembly 210 according to the second embodiment. The electrode assembly 210 is disposed between the incident surface 204 and the exit surface 208. Unlike Figure 15 described above, Figure 21 shows a cross-sectional view perpendicular to the direction of travel (z direction) of the scan beam SB. In Figure 21, the positions of multiple entrance apertures 202a-202c are indicated by dashed lines.

The electrode assembly 210 has a first electrode surface 222a, a second electrode surface 224a, a third electrode surface 224b, a fourth electrode surface 222b, a fifth electrode surface 222c, and a sixth electrode surface 224c. The first electrode surface 222a and the second electrode surface 224a face each other at a first distance d1 in a first direction across the ion beam traveling from the first entrance aperture 202a to the first exit aperture 206a. The first direction is parallel to the slit width direction (p direction) of the first entrance aperture 202a. The third electrode surface 224b and the fourth electrode surface 222b face each other at a second distance d2 in a second direction across the ion beam traveling from the second entrance aperture 202b to the second exit aperture 206b. The second direction is parallel to the slit width direction (p direction) of the second entrance aperture 202b. The fifth electrode surface 222c and the sixth electrode surface 224c face each other at a third distance d3 in the third direction, across the ion beam traveling from the third entrance aperture 202c to the third exit aperture 206c. The third direction is parallel to the slit width direction (direction p) of the third entrance aperture 202c. Therefore, in the example shown in FIG. 21 , the first direction, second direction, and third direction are parallel to one another. Furthermore, the first distance d1, second distance d2, and third distance d3 are the same.

A power supply 112 is connected to the electrode assembly 210. The power supply 112 is configured in the same manner as in the first embodiment. The power supply 112 generates a potential difference between two opposing electrode surfaces. The power supply 112 generates a first potential difference between the first electrode surface 222a and the second electrode surface 224a, a second potential difference between the third electrode surface 224b and the fourth electrode surface 222b, and a third potential difference between the fifth electrode surface 222c and the sixth electrode surface 224c.

The electrode assembly 210 comprises a first electrode body 226 and a second electrode body 228. The first electrode body 226 has a first electrode surface 222a, a fourth electrode surface 222b, and a fifth electrode surface 222c. The second electrode body 228 has a second electrode surface 224a, a third electrode surface 224b, and a sixth electrode surface 224c. A first power source 130 is coupled to the first electrode body 226, and a second power source 132 is coupled to the second electrode body 228. In this case, the magnitudes of the first potential difference, the second potential difference, and the third potential difference are the same. However, the direction of the electric field generated between the two opposing electrode surfaces may be different. The direction of the first electric field Ea based on the first potential difference between the first electrode surface 222a and the second electrode surface 224a is the same as the direction of the third electric field Ec based on the third potential difference between the fifth electrode surface 222c and the sixth electrode surface 224c, but is opposite (or antiparallel to) the direction of the second electric field Eb based on the second potential difference between the third electrode surface 224b and the fourth electrode surface 222b.

A side plate 220 may be provided around the electrode assembly 210 to enclose the first electrode body 226 and the second electrode body 228. The side plate 220 may be configured to extend cylindrically from the front plate 216 toward the rear plate 218. The front plate 216, rear plate 218, and side plate 220 may form a housing that houses the electrode assembly 210. The front plate 216, rear plate 218, and side plate 220 may be grounded and have a ground potential.

Figure 22 is a plan view showing the schematic configuration of the current measuring device 214 according to the second embodiment. The current measuring device 214 comprises multiple current measuring devices 214a, 214b, and 214c. The multiple current measuring devices 214a-214c are configured to detect ion beams that have passed through the corresponding exit apertures 206a-206c and measure the beam current values. In Figure 21, the positions of the multiple exit apertures 206a-206c are indicated by dashed lines.

The current measuring device 214 may include a first current measuring device 214a, a second current measuring device 214b, and a third current measuring device 214c. The first current measuring device 214a detects the ion beam emitted from the first exit aperture 206a and measures the first beam current value. The second current measuring device 214b detects the ion beam emitted from the second exit aperture 206b and measures the second beam current value. The third current measuring device 214c detects the ion beam emitted from the third exit aperture 206c and measures the third beam current value.

Each of the multiple current measuring devices 214a-214c can be configured similarly to the current measuring device 114 according to the first embodiment described above. Each of the multiple current measuring devices 214a-214c can include a Faraday cup, an ammeter 236a-236c coupled to the Faraday cup, a suppression electrode having passage openings 242a, 242b, 242c, and a suppression power supply coupled to the suppression electrode.

The angle measurement device 200 may further include a measurement control device 244 (see FIG. 21). The measurement control device 244 includes a processor 244a and a memory 244b. The measurement control device 244 may be configured similarly to the measurement control device 144 according to the first embodiment described above. The measurement control device 244 outputs a command value for applying a variable voltage to the electrode assembly 210, thereby varying the potential difference ΔV between the two opposing electrode surfaces over time.

The measurement control device 244 acquires beam current values measured by multiple current measuring devices 214a-214c and calculates angular information using the acquired beam current values. For example, the measurement control device 244 can sum the first beam current value Ii1, second beam current value Ii2, and third beam current value Ii3 measured for a specific potential difference ΔVi, and calculate the intensity of the angular component using the summed beam current value Ii (= Ii1 + Ii2 + Ii3). The measurement control device 244 converts the potential difference ΔVi into an angle θpi in the p direction, thereby obtaining the beam current value Ii corresponding to the angle θpi. This makes it possible to obtain angular information in the p direction, which is oblique to the scanning direction (y direction).

In the second embodiment, the current measuring device 214 may be configured with only a single current measuring device instead of multiple current measuring devices 214a-214c. In this case, the current measuring device 214 may be configured with a single Faraday cup that detects the total of multiple ion beams emitted from each of the multiple emission apertures 206a-206c. In other words, the single Faraday cup is configured to detect the combined ion beam group including the ion beam emitted from the first emission aperture 206a, the ion beam emitted from the second emission aperture 206b, and the ion beam emitted from the third emission aperture 206c. In this case, the single Faraday cup can be used to measure the total value Ii (= Ii1 + Ii2 + Ii3) of the first beam current value Ii1, the second beam current value Ii2, and the third beam current value Ii3.

According to this embodiment, when multiple entrance openings 202a-202c and multiple exit openings 206a-206c are provided, the configuration of the electrode assembly can be simplified by using an electrode body that integrates multiple electrode surfaces to which a common applied voltage is applied.

Figure 23 is a cross-sectional view showing the schematic configuration of an electrode assembly 210A according to a modified example. Similar to the electrode assembly 210 shown in Figure 21 above, the electrode assembly 210A has a first electrode surface 222a, a second electrode surface 224a, a third electrode surface 224b, a fourth electrode surface 222b, a fifth electrode surface 222c, and a sixth electrode surface 224c.

The electrode assembly 210A comprises a first electrode body 226A, a second electrode body 228, and a third electrode body 230. The first electrode body 226A has a first electrode surface 222a. The second electrode body 228 has a second electrode surface 224a, a third electrode surface 224b, and a sixth electrode surface 224c. The third electrode body 230 has a fourth electrode surface 222b and a fifth electrode surface 222c. The first power source 130 is coupled to the first electrode body 226A and the third electrode body 230. The second power source 132 is coupled to the second electrode body 228.

Even when using the electrode assembly 210A according to this modified example, the same effects as those of the second embodiment described above can be achieved.

(Third embodiment)
24 is a plan view showing a schematic configuration of an incident surface 304 of an angle measurement device 300 according to the third embodiment. The angle measurement device 300 according to the third embodiment is configured to be able to measure angle information in the scan direction (y direction) of the scan beam SB and angle information in a direction (x direction) perpendicular to the scan direction of the scan beam SB. The angle measurement device 300 according to the third embodiment will be described below, focusing on differences from the above-mentioned embodiments, and description of commonalities will be omitted as appropriate.

Figure 24 shows an incident surface 304 having multiple incident apertures 302a to 302d viewed from the upstream side in the beam propagation direction (z direction). Multiple incident apertures 302a, 302b, 302c, and 302d are formed on the incident surface 304. The first incident aperture 302a, the second incident aperture 302b, and the third incident aperture 302c can be configured in the same manner as the multiple incident apertures 202a to 202c in the second embodiment described above. The slit width direction of the first incident aperture 302a, the second incident aperture 302b, and the third incident aperture 302c is the p direction, which is oblique to the scanning direction (y direction). The fourth incident aperture 302d is positioned in measurement range D, where the first incident aperture 302a, the second incident aperture 302b, and the third incident aperture 302c are formed, and is positioned away from the first incident aperture 302a, the second incident aperture 302b, and the third incident aperture 302c in the scanning direction (y direction). The slit width direction of the fourth incident aperture 302d is parallel to the scanning direction (y direction). The opening width w2d in the slit length direction of the fourth incident aperture 302d, for example, coincides with the measurement range D. The opening widths w1a, w1b, w1c, and w1d in the slit width direction of the multiple incident apertures 302a, 302b, 302c, and 302d are common to each other. The multiple incident apertures 302a-302d are formed to penetrate a front plate 316 having an incident surface 304.

Figure 25 is a plan view showing the schematic configuration of the exit surface 308 of the angle measurement device 300 relating to the third embodiment. Figure 25 shows the entrance surface 204 having multiple exit openings 306a to 306d as viewed from the downstream side in the beam propagation direction (z direction). Multiple exit openings 306a to 306d are formed in the exit surface 308. The multiple exit openings 306a to 306d can have the same shape and size as the corresponding entrance openings 302a to 302d. The multiple exit openings 306a to 306d are positioned so that their positions in the x and y directions perpendicular to the propagation direction of the scan beam SB coincide with the corresponding entrance openings 302a to 302d. The opening widths w3a, w3b, w3c, and w3d in the slit width direction of the multiple exit openings 306a to 306d may be the same as the opening widths w1a to w1d in the slit width direction of the corresponding entrance openings 302a to 302d. The opening widths w4a, w4b, and w4c in the slit length direction of the multiple exit openings 306a to 306d may be the same as the opening widths w2a to w2d in the slit length direction of the corresponding entrance openings 302a to 302d.

Figure 26 is a cross-sectional view showing the schematic configuration of an electrode assembly 310 according to the third embodiment. The electrode assembly 310 is disposed between the incident surface 304 and the exit surface 308. In Figure 26, the positions of multiple incident openings 302a-302d are indicated by dashed lines.

The electrode assembly 310 has a first electrode surface 322a, a second electrode surface 324a, a third electrode surface 324b, a fourth electrode surface 322b, a fifth electrode surface 322c, a sixth electrode surface 324c, a seventh electrode surface 324d, and an eighth electrode surface 322d. The first electrode surface 322a to the sixth electrode surface 324c can be configured similarly to the first electrode surface 222a to the sixth electrode surface 224c shown in FIG. 21 above. The seventh electrode surface 324d and the eighth electrode surface 322d face each other at a fourth distance d4 in the fourth direction across the ion beam traveling from the fourth entrance aperture 302d to the fourth exit aperture 306d. The fourth direction is parallel to the slit width direction (y direction) of the fourth entrance aperture 302d. In the example shown in FIG. 26, the fourth direction is oblique to the first, second, and third directions. The fourth distance d4 is the same as the first distance d1, the second distance d2, and the third distance d3.

A power supply 112 is connected to the electrode assembly 310. The power supply 112 is configured in the same manner as in the above-described embodiment. The power supply 112 generates a potential difference between two opposing electrode surfaces. The power supply 112 generates a first potential difference between the first electrode surface 322a and the second electrode surface 324a, a second potential difference between the third electrode surface 324b and the fourth electrode surface 322b, a third potential difference between the fifth electrode surface 322c and the sixth electrode surface 324c, and a fourth potential difference between the seventh electrode surface 324d and the eighth electrode surface 322d.

The electrode assembly 310 comprises a first electrode body 326, a second electrode body 328, and a third electrode body 330. The first electrode body 326 has a first electrode surface 322a, a fourth electrode surface 322b, and a fifth electrode surface 322c. The second electrode body 328 has a second electrode surface 324a, a third electrode surface 324b, a sixth electrode surface 324c, and a seventh electrode surface 324d. The third electrode body 330 has an eighth electrode surface 322d. A first power source 130 is coupled to the first electrode body 326 and the third electrode body 330, and a second power source 132 is coupled to the second electrode body 328. In this case, the magnitudes of the first potential difference, the second potential difference, the third potential difference, and the fourth potential difference are the same. However, the direction of the electric field generated between the two opposing electrode surfaces may be different. The direction of the first electric field Ea based on the first potential difference between the first electrode surface 322a and the second electrode surface 324a is the same as the direction of the third electric field Ec based on the third potential difference between the fifth electrode surface 322c and the sixth electrode surface 324c, but is opposite (or antiparallel to) the direction of the second electric field Eb based on the second potential difference between the third electrode surface 324b and the fourth electrode surface 322b. The direction of the fourth electric field Ed based on the fourth potential difference between the seventh electrode surface 324d and the eighth electrode surface 322d is oblique to the directions of the first electric field Ea, the second electric field Eb, and the third electric field Ec.

A side plate 320 may be provided around the electrode assembly 310 to enclose the first electrode body 326, the second electrode body 328, and the third electrode body 330. The side plate 320 may be configured to extend cylindrically from the front plate 316 toward the rear plate 318. The front plate 316, the rear plate 318, and the side plate 320 may form a housing that houses the electrode assembly 310. The front plate 316, the rear plate 318, and the side plate 320 may be grounded and have a ground potential.

Figure 27 is a plan view showing the schematic configuration of the current measuring device 314 according to the third embodiment. The current measuring device 314 comprises multiple current measuring devices 314a, 314b, 314c, and 314d. The multiple current measuring devices 314a to 314d are configured to detect ion beams that have passed through the corresponding exit apertures 306a to 306d and measure the beam current values. In Figure 27, the positions of the multiple exit apertures 306a to 306d are indicated by dashed lines.

The current measuring device 314 may include a first current measuring device 314a, a second current measuring device 314b, a third current measuring device 314c, and a fourth current measuring device 314d. The first current measuring device 314a detects the ion beam emitted from the first exit aperture 306a and measures the first beam current value. The second current measuring device 314b detects the ion beam emitted from the second exit aperture 306b and measures the second beam current value. The third current measuring device 314c detects the ion beam emitted from the third exit aperture 306c and measures the third beam current value. The fourth current measuring device 314d detects the ion beam emitted from the fourth exit aperture 306d and measures the fourth beam current value.

Each of the multiple current measuring devices 314a-314d can be configured similarly to the current measuring device 114 according to the first embodiment described above. Each of the multiple current measuring devices 314a-314d can include a Faraday cup, an ammeter coupled to the Faraday cup, a suppression electrode having passage openings 342a, 342b, 342c, and 342d, and a suppression power supply coupled to the suppression electrode.

The angle measurement device 300 may further include a measurement control device 344 (see FIG. 26). The measurement control device 344 includes a processor 344a and a memory 344b. The measurement control device 344 may be configured similarly to the measurement control device 144 according to the first embodiment described above. The measurement control device 344 outputs a command value for applying a variable voltage to the electrode assembly 310, thereby varying the potential difference ΔV between the two opposing electrode surfaces over time.

The measurement control device 344 acquires beam current values measured by multiple current measuring devices 314a-314d and calculates angular information using the acquired beam current values. For example, the measurement control device 344 sums the first beam current value Ii1, second beam current value Ii2, and third beam current value Ii3 measured for a specific potential difference ΔVi, and calculates the intensity of the angular component in the p direction using the summed beam current value Ii (= Ii1 + Ii2 + Ii3). The measurement control device 344 converts the potential difference ΔVi into an angle θpi in the p direction, thereby obtaining the beam current value Ii at the angle θpi. This makes it possible to obtain angular information in the p direction, which is oblique to the scan direction (y direction).

The measurement control device 344 acquires the fourth beam current value Ii4 measured for a specific potential difference ΔVi, and calculates the intensity of the angular component in the y direction using the fourth beam current value Ii4. The measurement control device 344 converts the potential difference ΔVi into an angle θyi to obtain the beam current value Ii4 at the angle θyi. This makes it possible to obtain angle information in the scan direction (y direction).

The measurement control device 344 calculates angle information in the direction perpendicular to the scanning direction (x direction) using angle information in the scanning direction (y direction) and angle information in the p direction, which is oblique to the scanning direction (y direction). A known method for calculating angle information in the direction perpendicular to the scanning direction (x direction), for example, can be used, such as the method described in JP 2019-169407 A.

In the third embodiment, the current measuring device 314 may be a single current measuring device instead of the first to third current measuring devices 314a to 314c. In this case, the current measuring device 314 may include a first current measuring device that detects the sum of multiple ion beams extracted from each of the first to third extraction apertures 306a to 306c to measure a first beam current value, and a second current measuring device that detects the ion beam extracted from the fourth extraction aperture 306d to measure a second beam current value. The first current measuring device is configured to detect a group of ion beams that is a combination of all of the ion beams extracted from the first extraction aperture 306a, the second extraction aperture 306b, and the third extraction aperture 306c. In this case, the first current measuring device can be used to measure the total value Ii (= Ii1 + Ii2 + Ii3) of the first beam current value Ii1, second beam current value Ii2, and third beam current value Ii3.

Figure 28 is a cross-sectional view showing the schematic configuration of an electrode assembly 310A according to a modified example. Similar to the electrode assembly 310 shown in Figure 26 above, the electrode assembly 310A has a first electrode surface 322a, a second electrode surface 324a, a third electrode surface 324b, a fourth electrode surface 322b, a fifth electrode surface 322c, a sixth electrode surface 324c, a seventh electrode surface 324d, and an eighth electrode surface 322d.

The electrode assembly 310A comprises a first electrode body 326A having a first electrode surface 322a, a second electrode body 328A having a second electrode surface 324a and a third electrode surface 324b, a third electrode body 330A having a fourth electrode surface 322b and a fifth electrode surface 322c, a fourth electrode body 332 having a sixth electrode surface 324c, a fifth electrode body 334 having a seventh electrode surface 324d, and a sixth electrode body 336 having an eighth electrode surface 322d. A first power source 130 is coupled to the first electrode body 326A, the third electrode body 330A, and the sixth electrode body 336. A second power source 132 is coupled to the second electrode body 328A, the fourth electrode body 332, and the fifth electrode body 334. The power supplies coupled to the fifth electrode body 334 and the sixth electrode body 336 may be reversed, with the first power supply 130 coupled to the fifth electrode body 334 and the second power supply 132 coupled to the sixth electrode body 336.

The electrode assembly 310A further includes a seventh electrode body 338. The seventh electrode body 338 is disposed between the electrode group including the first electrode body 326A, the second electrode body 328A, the third electrode body 330A, and the fourth electrode body 332, and the fifth electrode body 334. The seventh electrode body 338 is grounded and has a ground potential.

Even when using the electrode assembly 310A according to this modified example, the same effects as those of the third embodiment described above can be achieved.

Next, we will explain the ion extraction device that generates the ion beam. Figure 29 is a schematic diagram of the ion extraction device according to the first embodiment. The ion extraction device includes an ion source 20 that generates plasma containing desired ions, and an extraction unit 22 that extracts a group of ions containing the desired ions from the ion source 20 or the arc chamber 20a to generate an ion beam IB.

As described above with reference to Figure 1 etc., the extraction section 22 provided downstream of the ion source 20 extracts a group of ions from the internal space 20b of the ion source 20 through the front slit 20c to generate an ion beam IB. Hereinafter, the opening of the front slit 20c from which a group of ions including the desired ions that make up the ion beam IB is extracted will be referred to as the first opening OP1. As described above with reference to Figure 1 etc., the first opening OP1 of the front slit 20c has a slit shape with a long opening width in the horizontal direction (x1 direction) and a short opening width in the vertical direction (y direction). In other words, the opening width of the first opening OP1 in the horizontal direction is larger than the opening width of the first opening OP1 in the vertical direction.

The extraction section 22 comprises, from downstream to upstream in the direction of travel of the ion beam IB (from right to left in Figure 29), a reference electrode 22b, a suppression electrode 22a, and a movable conductor 22e.

The reference electrode 22b, represented as the second extraction electrode 22b in FIG. 1 and other figures, has a second opening OP2 through which the ion beam IB passes, and a reference potential such as ground potential V _gnd is applied to it. Hereinafter, for convenience, the ground potential V _gnd or reference potential is assumed to be zero (0). A potential higher than such a reference potential V _gnd (=0) is conveniently referred to as a positive potential, and a potential lower than such a reference potential V _gnd (=0) is conveniently referred to as a negative potential. The second opening OP2, represented as the second extraction opening 22d in FIG. 1 and other figures, has a slit shape with a long opening width in the horizontal direction (x1 direction) and a short opening width in the vertical direction (y direction), similar to the front slit 20c. In other words, the opening width of the second opening OP2 in the horizontal direction is larger than the opening width of the second opening OP2 in the vertical direction.

The suppression electrode 22a, represented as the first extraction electrode 22a in FIG. 1 and other figures, has a third opening OP3 through which the ion beam IB passes, and is applied with a negative suppression potential _Vsup lower than the reference potential _Vgnd . The third opening OP3, represented as the first extraction opening 22c in FIG. 1 and other figures, has a slit shape with a long opening width in the horizontal direction (x1 direction) and a short opening width in the vertical direction (y direction), similar to the front slit 20c. In other words, the opening width of the third opening OP3 in the horizontal direction is larger than the opening width of the third opening OP3 in the vertical direction. The suppression electrode 22a is disposed between a movable conductor 22e (described later) on the upstream side and a reference electrode 22b on the downstream side.

A positive extraction potential V _ext higher than the reference potential V _gnd is applied to the front slit 20 c and/or the arc chamber 20 a of the ion source 20 .

The movable conductor 22e is sandwiched between the upstream front slit 20c and the downstream suppression electrode 22a. The movable conductor 22e has a fourth opening OP4 through which the ion beam IB passes. Similar to the front slit 20c, the fourth opening OP4 has a slit shape with a long opening width in the horizontal direction (x1 direction) and a short opening width in the vertical direction (y direction). In other words, the horizontal opening width of the fourth opening OP4 is larger than the vertical opening width of the fourth opening OP4. It is preferable that the size of the fourth opening OP4 be larger than the size of the first opening OP1.

In the illustrated example, a control potential Vctl, which is a positive potential between a positive extraction potential _Vext and a zero reference potential _Vgnd , is applied to the movable conductor 22e. The control potential _Vctl may be realized by an additional potential _Vadd connected in series in the opposite direction to the extraction potential _Vext . Specifically, the absolute value of _the additional potential _Vadd is smaller than the absolute value of the extraction potential _Vext , and the control potential _Vctl is expressed as " _Vext - _Vadd "(>0). Note that the movable conductor 22e may be configured to be insulated from specific potentials such as the reference potential _Vgnd , the extraction potential _Vext , the additional potential _Vadd , the suppression potential _Vsup , and a constant potential (not shown). Alternatively, the same positive extraction potential V _ext as that of the front slit 20 c (ion source 20) may be applied to the movable conductor 22 e by electrically connecting the movable conductor 22 e to the front slit 20 c via a conductor (for example, in FIG. 29 , the additional potential V _add is set to zero).

The first opening OP1 of the front slit 20c, the second opening OP2 of the reference electrode 22b, the third opening OP3 of the suppression electrode 22a, and the fourth opening OP4 of the movable conductor 22e are all similar slits that are long in the x1 direction (in Figure 29, each slit is shown schematically in the y direction, which is the short direction). The ion beam IB extracted from the ion source 20 by this extraction section 22 passes through the first opening OP1 of the front slit 20c, the fourth opening OP4 of the movable conductor 22e, the third opening OP3 of the suppression electrode 22a, and the second opening OP2 of the reference electrode 22b, in that order.

The two downstream electrodes in the extraction section 22, i.e., the suppression electrode 22a and the reference electrode 22b, may be configured as an integrated electrode unit. In this case, the distance between the suppression electrode 22a and the reference electrode 22b in the direction of travel of the ion beam IB (the z1 direction in Figure 29) is constant or unchanging. In other words, the center-to-center distance along the direction of travel between the third opening OP3 of the suppression electrode 22a and the second opening OP2 of the reference electrode 22b is constant or unchanging.

On the other hand, the entire electrode unit integrally formed by the suppression electrode 22a and the reference electrode 22b may be provided so as to be movable along the traveling direction of the ion beam IB relative to the ion source 20. In the illustrated example, the distance along the traveling direction between the ion source 20 (strictly, the front slit 20c) and the electrode unit (strictly, the suppression electrode 22a) is expressed as the sum of a first distance Gap ₁ and a second distance Gap _2, which will be described later. As will be described later, in this embodiment, the first distance Gap ₁ in the traveling direction between the front slit 20c and the movable conductor 22e is variable, and by moving the electrode unit along the traveling direction, the second distance Gap ₂ in the traveling direction between the movable conductor 22e and the suppression electrode 22a is also variable.

The movable conductor 22e (and/or its fourth opening OP4) has a variable first distance _Gap1 in the traveling direction of the ion beam IB between it and the front slit 20c (and/or its first opening OP1). As schematically shown in FIG. 30 , the movable conductor 22e may be connected to the ion source 20 and/or the front slit 20c by an extension/contraction mechanism 22f that is extendable and contractible along the traveling direction. The first distance Gap1 between the front slit 20c (first opening OP1) and the movable conductor 22e (fourth opening OP4) increases and decreases depending on the extension and contraction of the extension/contraction mechanism _22f .

The extension mechanism 22f is preferably made of an insulating material and has insulating properties. In this case, as described above with reference to FIG. 29 , a control potential V _ctl (i.e., V _ext −V _add ) different from the extraction potential V _ext of the ion source 20 (front slit 20c) can be applied to the movable conductor 22e. In the example of FIG. 30 , a diode D connected in series in the same direction as the additional potential V _add and a feedback resistor R connected in parallel to the additional potential V _add are provided. On the other hand, the extension mechanism 22f may be made of a conductive material and have conductivity. In this case, the same extraction potential V _ext as that of the ion source 20 (front slit 20c) is applied to the movable conductor 22e (the additional potential V _add , diode D, and feedback resistor R are not provided).

The ion extraction device according to this embodiment configured as described above can use various parameters to appropriately control how ions constituting the ion beam IB are extracted from the ion source 20. Examples of parameters that can be controlled by the ion extraction device include a group of potential parameters such as a reference potential V _gnd (typically constant), a suppression potential V _sup , an extraction potential V _ext , and a control potential V _ctl (or an additional potential V _add ), and a group of distance parameters such as a first distance Gap ₁ between the front slit 20 c and the movable conductor 22 e, a second distance Gap ₂ between the movable conductor 22 e and the suppression electrode 22 a, and a distance Gap ₂ ′ between the front slit 20 c and the suppression electrode 22 a.

As described above, each potential parameter such as the reference potential V _gnd , the suppression potential V _sup , the extraction potential V _ext , and the control potential V _ctl may be variably or adaptively controlled, but in the following example, each potential parameter is substantially fixed, and mainly two distance parameters Gap ₁ and Gap ₂ are variably or adaptively controlled. The values of each potential parameter can be set arbitrarily, but for example, the reference potential V _gnd is "0 V," the suppression potential V _sup is "-2 kV," the extraction potential V _ext is "+40 kV," and the control potential V _ctl is "+30 kV."

To clarify the significance of variable control of the two distance parameters Gap ₁ and Gap ₂ in this embodiment, a comparative example involving variable control of one distance parameter, Gap ₂ ′, will be described with reference to FIG. 31 . This comparative example is substantially the same as the embodiment shown in FIGS. 29 and 30 except that it does not include a movable conductor 22e. That is, while the embodiments shown in FIGS. 29 and 30 include four electrodes or conductors 20c, 22e, 22a, and 22b, the comparative example shown in FIG. 31 includes three electrodes 20c, 22a, and 22b. As with the embodiment shown in FIGS. 29 and 30 , "+40 kV" (extraction potential V _ext ), "-2 kV" (suppression potential V _sup ), and "0 V" (reference potential V _gnd ) are applied to these electrodes 20c, 22a, and 22b, respectively. Equipotential lines are schematically shown between the electrodes 20c, 22a, and 22b.

31(a) shows the slit-shaped first opening OP1, third opening OP3, and second opening OP2 of each electrode 20c, 22a, and 22b in the short direction (y direction), and the left diagram of Fig. 31(b) shows the slit-shaped first opening OP1, third opening OP3, and second opening OP2 of each electrode 20c, 22a, and 22b in the long direction (x1 direction). In this comparative example, only the distance Gap ₂ ' between the front slit 20c and the suppression electrode 22a along the traveling direction of the ion beam IB (z1 direction) is substantially variable.

The diagram on the right side of Figure 31(a) shows a two-dimensional plot of the position y in the short direction (y direction) of the ion beam IB and the tilt angle y' with respect to the propagation direction (z1 direction) at the observation position shown in the diagram on the left side (a predetermined z1 direction position between the reference electrode 22b and the defining aperture 24g located at the entrance of the mass analysis magnet device 24a).The diagram on the right side of Figure 31(b) shows a two-dimensional plot of the position x1 in the long direction (x1 direction) of the ion beam IB and the tilt angle x1' with respect to the propagation direction at the observation position shown in the diagram on the left side.Such a two-dimensional distribution of the position (y or x1) and tilt angle (y' or x1') of the ion beam IB is expressed as the phase space distribution of the ion beam IB. That is, the diagram on the right side of Figure 31(a) shows the phase space distribution of the ion beam IB in the y direction (short direction), and the diagram on the right side of Figure 31(b) shows the phase space distribution of the ion beam IB in the x1 direction (longitudinal direction).

In the phase space distribution in each direction, the plots with black circles represent data measured at the observation position, and the plots with white circles represent ideal data. In the lateral direction of FIG. 31( a), it can be seen that the measured phase space distribution is spread in the y and y′ directions relative to the ideal phase space distribution. In the longitudinal direction of FIG. 31( b), it can be seen that the measured phase space distribution is distorted in an S-shape relative to the ideal phase space distribution, which is approximately linear along the x1′ axis (horizontal axis). The undesirable spread of the phase space distribution in FIG. 31( a) and the S-shape distortion of the phase space distribution in FIG. 31( b) can be reduced by increasing the distance Gap ₂ ′ (i.e., by moving the suppression electrode 22 a away from the front slit 20 c). However, there is an upper limit to the distance Gap ₂ ′ due to the device configuration, and the measured data in FIG. 31 were actually obtained at the maximum distance Gap ₂ ′ of the current device. Although it is possible to increase the maximum value of the distance Gap ₂ ', this would lead to an undesirable increase in the size of the ion extractor and therefore the ion implanter 10 .

The undesirable phase space distribution as shown in Fig. 31 is likely to occur particularly when the extraction current _Iext of the ion beam IB is small. For example, one of the causes of the undesirable phase space distribution is thought to be that the equipotential lines are significantly distorted immediately after the first opening OP1 of the front slit 20c in Fig. 31(a), causing the ion beam IB to be in a locally over-focused state.

The movable conductor 22e according to this embodiment can mitigate the overfocusing and subsequent divergence of the ion beam IB under low-current conditions where the extraction current _Iext is small, thereby achieving a desirable phase space distribution as shown by the white circles in FIG. 31 . FIG. 32(a) shows the overfocusing and divergence of the ion beam IB in a comparative example in which the movable conductor 22e is not provided, similar to FIG. 31(a). The extraction current _Iext in this figure is relatively low at 1 mA. In contrast, FIG. 32(b) shows how the movable conductor 22e mitigate the overfocusing and divergence of the ion beam IB when the extraction current _Iext is the same at 1 mA. In this example, the extension mechanism 22f is made of a conductor (e.g., graphite, tungsten, or molybdenum), so the movable conductor 22e is at the same potential (extraction potential _Vext ) as the front slit 20c.

In Figure 32(b), the ion beam IB also converges downstream of the first opening OP1 in the front slit 20c, but the position is near the fourth opening OP4 in the movable conductor 22e, which is further downstream from the first opening OP1 than in Figure 32(a). Furthermore, the degree of convergence of the ion beam IB is significantly reduced in Figure 32(b) than in Figure 32(a). As a result, in Figure 32(b), an ion beam IB with a desirable phase spatial distribution can be achieved even under low current conditions such as 1 mA. Note that the distance between the front slit 20c and the suppression electrode 22a is substantially the same in Figures 32(a) and 32(b). Thus, according to the embodiment of Figure 32(b), an ion beam IB with a desirable phase spatial distribution can be achieved without increasing the distance between the front slit 20c and the suppression electrode 22a compared to the comparative example of Figure 32(a) (i.e., without increasing the size of the device).

As described above, even if the movable conductor 22e is not applied with a control potential V _ctl (i.e., V _ext -V _add ) different from the extraction potential V _ext , simply by being disposed downstream of the front slit 20c, the effect of adjusting the phase space distribution and divergence of the ion beam IB can be achieved. This effect can be optimized by adjusting the distance (Gap ₁ ) between the front slit 20c and the movable conductor 22e in accordance with conditions such as the extraction current I _ext . Furthermore, when an arbitrary control potential V _ctl can be applied to the movable conductor 22e, an ion beam IB having an optimal phase space distribution and divergence can be achieved by adjusting the control potential V _ctl and/or the first distance Gap ₁ in accordance with conditions such as the extraction current I _ext . As described above, in the ion extraction device according to this embodiment, a control potential Vctl, which is a potential between the extraction potential _Vext and the reference potential _Vgnd, may be applied to the movable conductor _22e in order to control the phase space distribution of the ion beam IB extracted from the second opening OP2.

Fig. 33 shows a state where the extraction current _Iext is larger than that shown in Fig. 32(b). Specifically, Fig. 33(a) shows a state where the extraction current _Iext is 2 mA, and Fig. 33(b) shows a state where the extraction current _Iext is 4 mA. As can be seen from Fig. 32(b) _{where the extraction current Iext is} 1 mA, Fig. 33(a) where the extraction current _Iext is 2 mA, and Fig. 33(b) where the extraction current _Iext is 4 mA, the phase space distribution and divergence of the ion beam IB can be optimized for a given extraction current _Iext by reducing the first distance Gap1 between the front slit 20c and the movable conductor 22e as the extraction current _Iext increases. In FIG. 33(b), the first distance Gap ₁ is zero, and the front slit 20c and the movable conductor 22e are in close contact with each other, essentially forming one electrode or conductor.

As described above, in the ion extraction device according to this embodiment, the first distance _Gap1 between the first opening OP1 and the fourth opening OP4 is controlled so that the ion beam IB has a desired phase space distribution when it is irradiated onto the wafer.

Fig. 34 shows a first control example of the first distance Gap ₁ and the second distance Gap ₂ in accordance with the extract current I _ext . Fig. 34(a) shows a control mode of the total distance between the front slit 20c and the suppression electrode 22a in accordance with the extract current I _ext (as shown in Figs. 29 and 30, strictly speaking, the thickness of the movable conductor 22e must also be taken into consideration, but for convenience, this is expressed as the sum of the first distance Gap ₁ and the second distance Gap ₂ , "Gap ₁ + Gap ₂ "). Fig. 34(b) shows a control mode of the first distance Gap ₁ between the front slit 20c and the movable conductor 22e in accordance with the extract current I _ext .

As described above with reference to FIGS. 32 and 33 , the first distance Gap ₁ is controlled to increase as the extraction current I _ext decreases. Therefore, the first distance Gap ₁ is controlled to reach a maximum value G ₀ when the extraction current I _ext is at its minimum value of "0." Thereafter, until the extraction current I _ext reaches a threshold current I _th (described below), the total distance "Gap ₁ + Gap ₂ " is maintained at a constant value G _c . This means that the suppression electrode 22 a is fixed with respect to the front slit 20 c. Until the extraction current I _ext increases from "0" to the threshold current I _th , the first distance Gap ₁ is controlled to gradually decrease, as described above with reference to FIGS. 32 and 33 , thereby achieving an optimal ion beam IB.

The threshold current _Ith is the extract current _Iext at which the optimal first distance _Gap1 becomes "0" under a constant total distance _Gc . At this time, as shown in FIG. 33(b), the front slit 20c and the movable conductor 22e are in close contact with each other. In a region where the extract current _Iext is larger than the threshold current _Ith , the first distance _Gap1 cannot be made smaller than "0", so the second distance _Gap2 is controlled to gradually decrease while the first distance _Gap1 is "0". As a result, in a region where the extract current _Iext is larger than the threshold current _Ith , the total distance " _Gap1 (=0) + _Gap2 " gradually decreases from the constant value _Gc . 34, the first distance Gap ₁ is adaptively controlled for the extraction current I _ext that is equal to or less than the threshold current I _{th ,} and the second distance Gap 2 is adaptively controlled for the extraction current I _ext that is equal to or greater than the threshold current I _th . Therefore, an ion beam IB having an appropriate phase space distribution and divergence is realized for a wide range of extraction current I _ext .

Fig. 35 shows a second control example of the first distance Gap ₁ and the second distance Gap ₂ in accordance with the extract current I _ext . Fig. 35(a) shows a control mode of the total distance between the front slit 20c and the suppression electrode 22a in accordance with the extract current I _ext (as shown in Figs. 29 and 30, strictly speaking, the thickness of the movable conductor 22e must also be taken into consideration, but for convenience, this is expressed as the sum of the first distance Gap ₁ and the second distance Gap ₂ , "Gap ₁ + Gap ₂ "). Fig. 35(b) shows a control mode of the first distance Gap ₁ between the front slit 20c and the movable conductor 22e in accordance with the extract current I _ext .

34(b), in contrast to the first control example in which the first distance Gap ₁ could be continuously controlled, in the second control example shown in Fig. 35(b), the first distance Gap ₁ is controlled in a stepwise or discontinuous manner. For example, when the extraction current _Iext is between "0" and the first current _I1 , the first distance Gap ₁ is fixed to a first value _G1 , when the extraction current _Iext is between the first current _I1 and the second current _I2 , the first distance Gap ₁ is fixed to a second value _G2 that is smaller than the first value _G1 , and when the extraction current _Iext is between the second current _I2 and the threshold current _Ith , the first distance Gap ₁ is fixed to a third value _G3 that is smaller than the second value _G2 . As in the first control example, when the extracted current I _ext is equal to or greater than the threshold current I _th , the first distance Gap ₁ is fixed to “0”.

The second distance _Gap2 is continuously controlled relative to the first distance _Gap1 , which is controlled in stages in this manner. Specifically, the second distance _Gap2 is controlled to a maximum or local maximum value when the extraction current _Iext is at a minimum value near "0." At this time, the total distance " _Gap1 + _Gap2 " reaches a maximum value _Gmax . Thereafter, the second distance _Gap2 and the total distance " _Gap1 (= _G1 ) + _Gap2 " are gradually decreased until the extraction current _Iext reaches the first current _I1 . When _the extraction current Iext reaches the first current _I1 , the total distance " _Gap1 (= _G1 ) + _Gap2 " reaches a minimum or local minimum value.

Furthermore, when the extraction current _Iext reaches the first current _I1 , as described above, the first distance _Gap1 is reduced to the second value _G2 . Meanwhile, the second distance _Gap2 is increased to a maximum or local maximum value. At this time, the total distance " _Gap1 + _Gap2 " again reaches the maximum value _Gmax . Thereafter, the second distance _Gap2 and the total distance " _Gap1 (= _G2 ) + _Gap2 " are gradually reduced until the extraction current _Iext reaches the second current _I2 . When the extraction current _Iext reaches the second current _I2 , the total distance " _Gap1 (= _G2 ) + _Gap2 " becomes a minimum or local minimum value.

Furthermore, when the extraction current _Iext reaches the second current _I2 , as described above, the first distance _Gap1 is reduced to the third value _G3 . Meanwhile, the second distance _Gap2 is increased to the maximum value or local maximum value. At this time, the total distance " _Gap1 + _Gap2 " again reaches the maximum value _Gmax . Thereafter, the second distance _Gap2 and the total distance " _Gap1 (= _G3 ) + _Gap2 " are gradually reduced until the extraction current _Iext reaches the threshold current _Ith . When the extraction current _Iext reaches the threshold current _Ith , the total distance " _Gap1 (= _G3 ) + _Gap2 " becomes the minimum value or local minimum value.

Furthermore, when the extraction current _Iext reaches the threshold current _Ith , as described above, the first distance _Gap1 is reduced to the minimum value "0". Meanwhile, the second distance _Gap2 is increased to the maximum or local maximum value. At this time, the total distance " _Gap1 + _Gap2 " again takes on the maximum value _Gmax . Thereafter, as the extraction current _Iext increases from the threshold current _Ith , the second distance _Gap2 and the total distance " _Gap1 (=0) + _Gap2 " are gradually reduced. As a result, in the region where the extraction current _Iext is greater than the threshold current _Ith , the total distance " _Gap1 (=0) + _Gap2 " gradually decreases from the maximum value _Gmax . 35 , for an extraction current I _ext equal to or less than the threshold current I _th , the first distance Gap ₁ is adaptively controlled in a stepwise manner, and the second distance Gap ₂ is adaptively controlled continuously, while for an extraction current I _ext equal to or greater than the threshold current I _th, the second distance Gap ₂ is adaptively controlled continuously. Therefore, an ion beam IB having an appropriate phase space distribution and divergence is realized for a wide range of extraction current I _ext .

Next, with reference to Figure 29, we will explain examples of setting various parameters in the ion extraction device according to this embodiment. However, the method for setting each parameter is arbitrary and is not limited to the examples given below.

In the first step, the extraction potential V _ext (+40 kV in the previous example) and the suppression potential V _sup (−2 kV in the previous example) are set so as to obtain an ion beam IB with a desired energy.

In a second step, various apparatus parameters reflecting the state of the ion source 20 are set so as to obtain a desired extraction current _Iext . Examples of the apparatus parameters include at least one of the following: the gas species, gas flow rate, vaporizer temperature, arc current _Iarc , arc voltage, source magnet current, an effective extraction current which is the total amount of charge carried per unit time by an ion group including desired ions extracted from the ion source 20; and the beam current of the ion beam IB irradiated onto the wafer, all of which are set as parameters of the ion source 20. At least one of the various apparatus parameters set in this way in the second step can be acquired by the ion source state acquisition unit 401. Furthermore, the effective extraction current and the additional potential _Vadd which is the potential difference between the extraction potential _Vext applied to the ion source 20 and the control potential Vctl applied to the movable conductor _22e can be acquired by the electrical information acquisition unit 402.

In a third step, the additional potential V _add (i.e., the control potential V _ctl ) is adjusted so as to obtain a desired extraction current I _ext under the apparatus parameters set in the second step. Here, the relational expression that the extraction current I _ext is approximately proportional to m ^−½ ·V _add ^3/2, where m is the molecular weight of the ion species determined by the apparatus parameters, is utilized. In this manner, in the ion extraction apparatus according to this embodiment, the control potential V _{ctl applied to the movable conductor 22 e may be controlled in accordance with the apparatus parameters acquired by the ion source status acquisition unit 401. Furthermore, in the ion extraction apparatus according to this embodiment, the control potential V ctl applied} to the movable conductor 22 e may be controlled in accordance with the additional potential V _add and the effective extraction current acquired by the electrical information acquisition unit 402.

In the fourth step, the second distance Gap ₂ is adjusted so that the tilt angle x1′ in the phase space distribution in the x1 direction (see FIG. 31(b)) falls within the design range of the beamline A. Here, the relational expression that the extraction current I _ext is approximately proportional to m ^−1/2 ·V _ext ^3/2 ·Gap ₂ ⁻² is utilized.

In the fifth step, the orbital axis of the ion beam IB is adjusted by adjusting the position, attitude, aperture shape, etc. of the suppression electrode 22a, etc. This adjustment changes the center of gravity of the phase space distribution, but does not change its shape.

34( b ), the first distance _Gap1 is adjusted. In this manner, in the ion extraction apparatus according to this embodiment, the first distance Gap1 between the first opening OP1 and the fourth opening OP4 in the traveling direction of the ion beam IB may be controlled in accordance with the state of the ion source ₂₀ obtainable by the ion source state obtaining unit 401 so that the ion beam IB has a desired phase space distribution when irradiated onto a wafer. In addition, in the ion extraction apparatus according to this embodiment, the first distance _Gap1 between the first opening OP1 and the fourth opening OP4 in the traveling direction of the ion beam IB may be controlled in accordance with the additional potential V _add and the effective extraction current obtained by the electrical information obtaining unit 402.

Depending on the density of the plasma generated by the ion source 20, a desired ion beam IB may be obtained without adjusting the first distance Gap _1. In particular, when the plasma is dense, the first distance Gap ₁ may be fixed to zero (see FIG. 33(b)), for example, to substantially disable the movable conductor 22e. In this way, whether or not to use the movable conductor 22e may be selected depending on the density of the plasma generated by the ion source 20.

The ion extraction system according to this embodiment may adaptively control the various parameters described above by utilizing an angle measurement device provided in the beam profiler 46. In this case, the angle measurement device constitutes a phase space distribution measurement device that measures the phase space distribution of the ion beam IB downstream of the reference electrode 22 b. At least one of the first distance Gap ₁ between the first aperture OP1 and the fourth aperture OP4 in the traveling direction of the ion beam IB and the control potential V _ctl (i.e., additional potential V _add ) applied to the movable conductor 22 e may be controlled according to the phase space distribution of the ion beam IB measured by such a phase space distribution measurement device.

36 is a schematic diagram of an ion extraction device according to a second embodiment. The ion extraction device includes an ion source 20 that generates plasma containing desired ions DI, an extraction unit 22 that extracts ions containing the desired ions DI from the ion source 20 or the arc chamber 20a to generate a first ion beam IB1, a mass analysis magnet 24a serving as a first beam deflection device that deflects the first ion beam IB1 by applying a magnetic field or magnetic field, a mass analysis slit 24b (see FIG. 1, etc.) serving as a first separation opening that passes the desired ions DI contained in the first ion beam IB1 deflected by the mass analysis magnet 24a, and a potential difference setting unit 403 that sets a potential difference between a first region R1, which is at least a portion of the region between the outlet of the extraction unit 22 and the entrance of the mass analysis magnet 24a, and a second region R2, which is at least a portion of the region between the entrance and exit of the mass analysis magnet 24a. When the first ion beam IB1 passes through the mass analysis slit 24b, the metamorphic ions MI are reduced as described below, and it becomes a second ion beam containing a large amount of desired ions DI. This second ion beam is irradiated onto the wafer in the implantation processing chamber 14.

As schematically shown in the first region R1 of FIG. 36 , the first ion beam IB1 extracted from the ion source 20 by the extraction unit 22 may include undesired ions OI in addition to desired ions DI. For example, if the desired ions DI are divalent ions, the undesired ions OI are singly charged dimer ions. A divalent ion serving as a desired ion DI is conveniently represented as X ²⁺ . Here, "X" represents a unit atom or unit molecule having a mass M, "2+" represents the charge of the ion (positive divalent), and indicates that the total charge is 2e, where e is the unit charge. A dimer ion serving as an undesired ion OI is conveniently represented as X ₂₊ . Here, "X ₂ " represents two unit atoms or unit molecules having a mass M (hence, the total mass is 2M), "+" represents ^the charge of the ion (positive monovalent), and indicates that the total charge is e, where e is the unit charge. The desired ions DI may be positive or negative monovalent ions, negative divalent ions, or positive or negative trivalent or higher polyvalent ions.

As described above, when desired ions DI with mass M and charge 2e and undesired ions OI with mass 2M and charge e enter the mass analysis magnet device 24a as is, they are deflected to different central orbits by the applied magnetic field, allowing them to be properly separated by the subsequent mass analysis slit 24b, etc. (i.e., undesired ions OI are properly removed). This is because the Larmor radii, which are the radii of rotational motion in the magnetic field, are different for desired ions DI and undesired ions OI.

Specifically, the Larmor radius r is expressed as r = (2mE) ^1/2 /(qB), where m is the mass of the ion, E is the energy of the ion, q is the charge of the ion, and B is the magnetic flux density applied by the mass analysis magnet device 24a. The desired ions DI and undesired ions OI have energies of 2 eV _ext and eV _ext , respectively, due to the extraction potential V _ext in the extraction section 22. In this case, the Larmor radius of the desired ion DI is (2·M·2 eV _ext ) ^1/2 /(2 eB) = (MV _ext ) ^1/2 /(e ^1/2 B), and the Larmor radius of the undesired ion OI is (2·2M·eV _ext ) ^1/2 /(eB) = 2(MV _ext ) ^1/2 /(e ^1/2 B). In this way, the Larmor radius of the undesired ion OI is twice the Larmor radius of the desired ion DI, and both ions DI and OI are appropriately separated through the mass analysis magnet device 24a. Note that here, the potential difference provided by the potential difference setting unit 403 is set to zero for convenience.

However, some of the undesired ions OI may be transformed into modified ions MI by undergoing at least one of decomposition and charge conversion when passing through the first region R1. If the undesired ions OI are dimer ions _X2 ⁺ , X ⁺ with mass M and charge e may be generated as modified ions MI. For example, suppose modified ions MI are generated near the boundary between the first region R1 and the second region R2. In this case, the energy of the undesired ions OI before being decomposed into modified ions MI is _eVext , as described above. Because the undesired ions OI are split into modified ions MI and neutral atoms or molecules N, the energy of the modified ions MI is _eVext /2. The Larmor radius of the modified ions MI is (2·M· _eVext /2) ^1/2 /(eB)=( _MVext ) ^1/2 /(e1 ^/2B ). This is approximately equal to the Larmor radius of the desired ion DI mentioned above.

For this reason, the modified ions MI cannot be separated from the desired ions DI using only the mass analysis magnet device 24a and mass analysis slit 24b. Note that the modified ions MI are not limited to this example, and may be any ions that have a central orbit or Larmor radius substantially equivalent to that of the desired ions DI (i.e., ions that cannot be substantially separated from the desired ions DI using only the mass analysis magnet device 24a and mass analysis slit 24b). It is undesirable to irradiate a wafer in the implantation processing chamber 14 with a second ion beam that contains modified ions MI in this way.

Therefore, in this embodiment, a potential difference setting unit 403 is provided. The potential difference set by the potential difference setting unit 403 is set so that the modified ions MI and desired ions DI, which are generated when some of the ions in the first ion beam IB1 passing through the first region R1 (for example, undesired ions OI) undergo at least one of decomposition and charge conversion, have different central orbits in the second region R2, and at least some of the modified ions MI cannot pass through the mass analysis slit 24b.

For example, the potential difference setting unit 403 applies a first reference potential _Vr1 to the first region R1, and applies a first bias potential _Vb1 , which is different from the first reference potential _Vr1 , to the second region R2. The first reference potential _Vr1 may be equal to the ground potential _Vgnd , which serves as a third reference potential applied to the reference electrode 22b, and will be assumed to be zero (0) below for convenience. A potential higher than this first reference potential _Vr1 (= 0) is conveniently referred to as a positive potential, and a potential lower than this first reference potential _Vr1 (= 0) is conveniently referred to as a negative potential.

Furthermore, a fifth opening OP5 through which the first ion beam IB1 passes may be provided at at least one of the entrance and exit of the mass analysis magnet device 24a, and second suppression electrodes 24e (entrance side) and/or _24f (exit side) to which a second suppression potential Vsup2 lower than the potential _Vb1 of the second region R2 is applied may be provided. The fifth opening OP5 may have a slit shape with a long opening width in the horizontal direction and a short opening width in the vertical direction, similar to the front slit 20c ( FIG. 29 , etc.). Note that the fifth opening OP5 may be provided as a separate member from the second suppression electrodes 24e and/or 24f.

36, the potential difference setting unit 403 applies a zero first reference potential _Vr1 (not shown) to the first region R1 and applies a negative first bias potential _Vb1 to the second region R2. The first bias potential _Vb1 may be applied to the housing of the mass analysis magnet device 24a, for example.

37 schematically shows an example of the change in potential along the traveling direction of the first ion beam IB across the first region R1 and the second region R2. The potential at the front slit 20c provided at the start position of the first region R1 is the extraction potential V _ext (e.g., +40 kV). The potential decreases approximately linearly from the front slit 20c to the suppression electrode 22a (in this embodiment, the movable conductor 22e is not provided). The potential at the suppression electrode 22a is the aforementioned suppression potential V _sup (e.g., −2 kV). In the region downstream thereof, the potential is maintained at a first reference potential V _r1 of zero by the reference electrode 22b and the like.

Next, when the mass analysis magnet 24a and/or the entrance to the second region R2 are approached, the potential is locally lowered to a second suppression potential _Vsup2 by the second suppression electrode 24e at the upstream stage. As shown in the figure, the second suppression potential _Vsup2 is lower than the first suppression potential _Vsup and the first reference potential _Vr1 . A negative first bias potential _Vb1 is applied to the main body of the subsequent mass analysis magnet 24a. This first bias potential _Vb1 is higher than the second suppression potential _Vsup2 and lower than the first reference potential _Vr1 . At the exit of the mass analysis magnet 24a and/or the second region R2, the potential is locally lowered to the second suppression potential _Vsup2 by the second suppression electrode 24f at the downstream stage.

The modified ions MI generated by the transformation of the undesired ions OI as dimer ions have the aforementioned energy eV _ext /2 due to the extraction potential V _ext and energy −eV _b1 due to the first bias potential V _b1 near the boundary between the first region R1 and the second region R2. Therefore, the total energy of the modified ions MI is expressed as e(V _ext /2−V _b1 ). On the other hand, the divalent desired ions DI have energy 2 eV _ext due to the extraction potential V _ext and energy −2 eV _b1 due to the first bias potential V _b1 . Therefore, the total energy of the desired ions DI is expressed as 2e(V _ext −V _b1 ).

Due to the change in energy brought about by the first bias potential V _b1 as described above, the central orbit or Larmor radius of the deformed ions MI in the mass analysis magnet 24a or the second region R2 deviates from the central orbit or Larmor radius of the desired ions DI. Specifically, the Larmor radius of the desired ions DI is (2·M·2e(V _ext −V _b1 )) ^1/2 /(2eB)=(M(V _ext −V _b1 )) ^1/2 /(e ^1/2 B), while the Larmor radius of the deformed ions MI is (2·M·e(V _ext /2−V _b1 )) ^1/2 /(eB)=(M(V _ext −2V _b1 )) ^1/2 /(e ^1/2 B). 36, the central orbit of the deformed ion MI is deviated outward from the central orbit (solid line) of the desired ion DI by the negative first bias potential _Vb1 applied to the second region R2. The deformed ion MI deviated outward in this manner is blocked by the mass analysis slit 24b or the like serving as the first separation aperture in the subsequent stage.

Figure 38 shows specific examples of central trajectories of various ions based on the extraction direction of the first ion beam IB. "++" represents the central trajectory of the positively doubly charged desired ion DI, "Dimer" represents the central trajectory of the undesired ion OI as a singly charged dimer ion, "P1" represents the central trajectory of the modified ion MI generated at position P1 in Figure 36 (just before entering the mass analysis magnet device 24a), "P2" represents the central trajectory of the modified ion MI generated at position P2 in Figure 36 (just after entering the mass analysis magnet device 24a), and "P3" represents the central trajectory of the modified ion MI generated at position P3 in Figure 36 (even later than position P2).

As shown by the arrows in the enlarged partial view of FIG. 38 , the central orbit of the deformed ion MI varies depending on the generation position P1, P2, or P3. Here, when the generation position of the deformed ion MI changes from the upstream P1 to the downstream P2, the central orbit of the deformed ion MI generated at the position P2 approaches but does not coincide with the central orbit of the desired ion DI. Furthermore, when the generation position of the deformed ion MI changes further downstream to P3, the central orbit of the deformed ion MI generated at the position P3 moves away from the central orbit of the desired ion DI. Thus, in the examples of FIGS. 36 to 38 , in which a negative first bias potential V _b1 is applied to the second region R2 and/or the mass analysis magnet device 24 a, the central orbit of the deformed ion MI can be effectively prevented from interfering with the central orbit of the desired ion DI, regardless of the generation position of the deformed ion MI. Therefore, it is preferable that the first bias potential V _b1 applied to the second region R2 and/or the mass analysis magnet device 24 a be negative.

39 shows an example in which the potential difference setting unit 403 applies a zero first reference potential _Vr1 (not shown) to the first region R1 and a positive first bias potential _Vb1 to the second region R2. The first bias potential _Vb1 may be applied to the housing of the mass analysis magnet device 24a, for example.

40 schematically shows an example of the change in potential along the traveling direction of the first ion beam IB across the first region R1 and the second region R2. The potential at the front slit 20c is the extraction potential V _ext (e.g., +40 kV). The potential decreases approximately linearly from the front slit 20c to the suppression electrode 22a (in this embodiment, the movable conductor 22e is not provided). The potential at the suppression electrode 22a is the aforementioned suppression potential V _sup (e.g., −2 kV). In the downstream region, the potential is maintained at a first reference potential V _r1 of zero by the reference electrode 22b and the like provided at the start position of the first region R1.

Next, when the mass analysis magnet 24a and/or the entrance to the second region R2 are approached, the potential is locally lowered to a second suppression potential _Vsup2 by the second suppression electrode 24e at the upstream stage. As shown in the figure, the second suppression potential _Vsup2 is lower than the first suppression potential _Vsup and the first reference potential _Vr1 . A positive first bias potential _Vb1 is applied to the main body of the subsequent mass analysis magnet 24a. This first bias potential _Vb1 is higher than the first reference potential _Vr1 . At the exit of the mass analysis magnet 24a and/or the second region R2, the potential is locally lowered to the second suppression potential _Vsup2 by the second suppression electrode 24f at the downstream stage.

39, the central orbit of the modified ion MI is deviated inward from the central orbit (solid line) of the desired ion DI by the first positive bias potential _Vb1 applied to the second region R2. The modified ion MI deviated inward in this manner is blocked by the mass analysis slit 24b or the like serving as the first separation aperture in the subsequent stage.

Figure 41 shows specific examples of central trajectories of various ions based on the extraction direction of the first ion beam IB. "++" represents the central trajectory of a positively doubly charged desired ion DI, "Dimer" represents the central trajectory of an undesired ion OI as a singly charged dimer ion, "P1" represents the central trajectory of a modified ion MI generated at position P1 in Figure 39 (just before entering the mass analysis magnet device 24a), "P2" represents the central trajectory of a modified ion MI generated at position P2 in Figure 39 (just after entering the mass analysis magnet device 24a), and "P3" represents the central trajectory of a modified ion MI generated at position P3 in Figure 39 (even later than position P2).

As shown by the arrows in the enlarged partial view of FIG. 41 , the central orbit of the modified ion MI varies depending on the generation positions P1, P2, and P3. Here, the central orbit of the modified ion MI generated at the upstream position P1 is to the left of the central orbit of the desired ion DI, whereas the central orbit of the modified ion MI generated at the downstream position P2 is to the right of the central orbit of the desired ion DI. This means that the central orbit of the modified ion MI generated between P1 and P2 (particularly near P2) interferes with the central orbit of the desired ion DI, making them indistinguishable. Thus, in the examples of FIGS. 39 to 41 in which a positive first bias potential V _b1 is applied to the second region R2 and/or the mass analysis magnet device 24 a, the central orbit of the modified ion MI may interfere with the central orbit of the desired ion DI depending on the generation position of the ion. Therefore, as described above, it is preferable that the first bias potential V _b1 applied to the second region R2 and/or the mass analysis magnet device 24 a is negative.

FIG. 42 is a schematic diagram of an ion extraction device according to the third embodiment. Components similar to those of the second embodiment in FIG. 36 and elsewhere are designated by the same reference numerals, and redundant explanations will be omitted.

In this embodiment, the potential difference setting unit 403 applies a second reference potential _Vr2 to the second region R2 and a second bias potential Vb2, which is different from the second reference potential _Vr2 , to the first region _R1 . The second reference potential _Vr2 may be equal to the ground potential _Vgnd , which serves as a third reference potential applied to the reference electrode 22b, and will be assumed to be zero (0) below for convenience. A potential higher than this second reference potential _Vr2 (= 0) is conveniently referred to as a positive potential, and a potential lower than this second reference potential _Vr2 (= 0) is conveniently referred to as a negative potential.

Furthermore, a fifth opening OP5 through which the first ion beam IB1 passes may be provided at the entrance of the mass analysis magnet device 24a, and a second suppression electrode 24e to which a negative second suppression potential _Vsup2 lower than the potential _Vr2 of the second region R2 is applied may be provided. The fifth opening OP5 may have a slit shape with a long opening width in the horizontal direction and a short opening width in the vertical direction, similar to the front slit 20c (Figure 29, etc.). Note that the fifth opening OP5 may be provided as a separate member from the second suppression electrode 24e.

42, the potential difference setting unit 403 applies a zero second reference potential _Vr2 to the second region R2 (e.g., the housing of the mass analysis magnet device 24a) and applies a positive second bias potential _Vb2 to the first region R1. The second bias potential _Vb2 may be applied to, for example, the housing 22g that surrounds most of the first region R1.

43 schematically shows an example of the change in potential along the traveling direction of the first ion beam IB across the first region R1 and the second region R2. The potential at the front slit 20c is the extraction potential V _ext (e.g., +40 kV). The potential decreases approximately linearly from the front slit 20c to the suppression electrode 22a (in this embodiment, the movable conductor 22e is not provided). The potential at the suppression electrode 22a is the aforementioned suppression potential V _sup (e.g., −2 kV). In the downstream region, the potential is maintained at a positive second bias potential V _b2 by the reference electrode 22b and the housing 22g provided at the start position of the first region R1.

Next, when the sample approaches the entrance to the mass analysis magnet device 24a and/or the second region R2, the potential is locally reduced to a second suppression potential _Vsup2 by the second suppression electrode 24e. As shown in the figure, the second suppression potential _Vsup2 is lower than the first suppression potential _Vsup and the second bias potential _Vb2 . A second reference potential _Vr2 of zero is applied to the main body of the subsequent mass analysis magnet device 24a.

42, the central trajectory of the deformed ion MI is deviated outward from the central trajectory (solid line) of the desired ion DI by the second positive bias potential _Vb2 applied to the first region R1. The deformed ion MI deviated outward is blocked by the mass analysis slit 24b or the like serving as the first separation aperture in the subsequent stage.

Figure 44 shows specific examples of central trajectories of various ions based on the extraction direction of the first ion beam IB. "++" represents the central trajectory of the positively doubly charged desired ion DI, "Dimer" represents the central trajectory of the undesired ion OI as a singly charged dimer ion, "P1" represents the central trajectory of the modified ion MI generated at position P1 in Figure 42 (just before entering the mass analysis magnet device 24a), "P2" represents the central trajectory of the modified ion MI generated at position P2 in Figure 42 (just after entering the mass analysis magnet device 24a), and "P3" represents the central trajectory of the modified ion MI generated at position P3 in Figure 42 (even later than position P2).

As shown by the arrows in the enlarged partial view of FIG. 44 , the central orbit of the deformed ion MI varies depending on the generation position P1, P2, or P3. Here, when the generation position of the deformed ion MI changes from the upstream P1 to the downstream P2, the central orbit of the deformed ion MI generated at the position P2 approaches but does not coincide with the central orbit of the desired ion DI. When the generation position of the deformed ion MI changes further downstream to P3, the central orbit of the deformed ion MI generated at the position P3 moves away from the central orbit of the desired ion DI. Thus, in the examples of FIGS. 42 to 44 in which a positive second bias potential V _b2 is applied to the first region R1 and/or the housing 22g, the central orbit of the deformed ion MI can be effectively prevented from interfering with the central orbit of the desired ion DI, regardless of the generation position of the deformed ion MI. Therefore, it is preferable that the second bias potential V _b2 applied to the first region R1 and/or the housing 22g be positive.

45 shows an example in which the potential difference setting unit 403 applies a zero second reference potential _Vr2 to the second region R2 and a negative second bias potential _Vb2 to the first region R1. The second bias potential _Vb2 may be applied to, for example, a housing 22g that surrounds most of the first region R1.

46 schematically shows an example of the change in potential along the traveling direction of the first ion beam IB across the first region R1 and the second region R2. The potential at the front slit 20c is the extraction potential V _ext (e.g., "+40 kV"). The potential decreases approximately linearly from the front slit 20c to the suppression electrode 22a (in this embodiment, the movable conductor 22e is not provided). The potential at the suppression electrode 22a is equivalent to a second suppression potential V _sup2 , which will be described later. In the downstream region, the potential is maintained at a negative second bias potential V _b2 by the reference electrode 22b, the housing 22g, and the like, which are provided at the start position of the first region R1.

Next, when the mass analysis magnet 24a and/or the entrance to the second region R2 are approached, the second suppression electrode 24e locally reduces the potential to a second suppression potential _Vsup2 . As shown in the figure, the second suppression potential _Vsup2 is lower than the second reference potential _Vr2 and the second bias potential _Vb2 . The second reference potential _Vr2 , which is zero, is applied to the main body of the subsequent mass analysis magnet 24a.

45, the central orbit of the deformed ion MI is deviated inward from the central orbit (solid line) of the desired ion DI by the second negative bias potential _Vb2 applied to the first region R1. The deformed ion MI deviated inward in this manner is blocked by the mass analysis slit 24b or the like serving as the first separation aperture in the subsequent stage.

Figure 47 shows specific examples of central trajectories of various ions based on the extraction direction of the first ion beam IB. "++" represents the central trajectory of the positively doubly charged desired ion DI, "Dimer" represents the central trajectory of the undesired ion OI as a singly charged dimer ion, "P1" represents the central trajectory of the modified ion MI generated at position P1 in Figure 45 (just before entering the mass analysis magnet device 24a), "P2" represents the central trajectory of the modified ion MI generated at position P2 in Figure 45 (just after entering the mass analysis magnet device 24a), and "P3" represents the central trajectory of the modified ion MI generated at position P3 in Figure 45 (even later than position P2).

As shown by the arrows in the enlarged partial view of FIG. 47 , the central orbit of the deformed ion MI varies depending on the generation positions P1, P2, and P3. Here, the central orbit of the deformed ion MI generated at the upstream position P1 is to the left of the central orbit of the desired ion DI, whereas the central orbit of the deformed ion MI generated at the downstream position P2 is to the right of the central orbit of the desired ion DI. This means that the central orbit of the deformed ion MI generated between P1 and P2 (particularly near P2) interferes with the central orbit of the desired ion DI and becomes indistinguishable. Thus, in the examples of FIGS. 45 to 47 in which a negative second bias potential V _b2 is applied to the first region R1 and/or the housing 22g, the central orbit of the deformed ion MI may interfere with the central orbit of the desired ion DI depending on the generation position. Therefore, as described above, it is preferable that the second bias potential V _b2 applied to the first region R1 and/or the housing 22g is positive.

As shown schematically in FIG. 36 (not shown in similar FIGS. 39, 42, and 45), the ion extraction device according to this embodiment may include a trajectory calculation unit 404 that calculates the central trajectories of the desired ions DI (solid lines) and the modified ions MI (dotted lines) based on the potential difference set by the potential difference setting unit 403. The calculations in the trajectory calculation unit 404 take into account the Larmor radius and the generation positions P1, P2, and P3 of the modified ions MI. The trajectory calculation unit 404 calculates, for example, the difference between the central trajectories of the desired ions DI and the modified ions MI in the deflection direction (x direction) by the mass analysis magnet device 24a serving as the first beam deflection device at the position of the mass analysis slit 24b (see FIG. 1, etc.) serving as the first separation aperture.

The ion extraction device according to this embodiment may also include a beam size adjustment unit 405 that adjusts the size or width of the first ion beam IB1 in the direction of deflection by the mass analysis magnet device 24a at the position of the mass analysis slit 24b. The beam size adjustment unit 405 may adjust the size or width of the first ion beam IB1 at the position of the mass analysis slit 24b, for example, based on the central trajectories of the desired ions DI and the modified ions MI calculated by the trajectory calculation unit 404. Specifically, the beam size adjustment unit 405 adjusts the size or width of the first ion beam IB1 so that most of the desired ions DI can pass through the mass analysis slit 24b and most of the modified ions MI cannot pass through the mass analysis slit 24b.

The beam size adjustment unit 405 may adjust the size or width of the ion beam exiting the mass analysis unit 24 by referring to the size or width of the ion beam measured by the first beam current measurement device 406. An example of the first beam current measurement device 406 is the injector Faraday cup 24c described above with reference to Figure 1, etc. This injector Faraday cup 24c may be located downstream of the mass analysis slit 24b as in Figure 1, etc., or may be located downstream of the mass analysis magnet device 24a and upstream of the mass analysis slit 24b.

Such a first beam current measuring device 406 measures the size or width of the ion beam in the deflection direction (x direction) by the mass analysis magnet device 24a serving as the first beam deflection device. When provided downstream of the mass analysis slit 24b, the first beam current measuring device 406 may measure the size or width of the first ion beam in the deflection direction by measuring the beam current of the second ion beam while changing the magnetic field applied by the mass analysis magnet device 24a. When provided upstream of the mass analysis slit 24b, the first beam current measuring device 406 may measure the size or width of the first ion beam in the deflection direction by measuring the beam current of the first ion beam while moving in the deflection direction (for example, while the injector Faraday cup 24c serving as the first beam current measuring device 406 is driven by the injector driver 24d).

The beam size adjustment unit 405 may adjust the distance (for example, the sum of the first distance Gap1 and the second distance Gap2 in FIG. 29 etc.) between the first opening OP1 in the ion source 20 and the suppression electrode 22a serving as the first suppression electrode in order to adjust the size or width of the ion beam by adjusting the extraction electric field distribution in the vicinity of the first opening OP1 through which the _first ion beam is extracted from the ion source _20. As described above, the suppression electrode 22a serving as the first suppression electrode has a third opening OP3 through which the first ion beam passes, and a first suppression potential _Vsup lower than the third reference potential _Vgnd applied to the reference electrode 22b is applied to the suppression electrode 22a.

The beam size adjustment unit 405 may adjust the distance between the first opening OP in the ion source 20 and the movable conductor 22e (for example, the first distance Gap ₁ in FIG. 29 etc.) in order to adjust the size or width of the ion beam by adjusting the extraction electric field distribution in the vicinity of the first opening OP1 through which the first ion beam is extracted from the ion source 20. As described above, the movable conductor 22e has a fourth opening OP4 through which the first ion beam passes, and the distance from the first opening OP1 through which the first ion beam is extracted from the ion source 20 is variable.

The beam size adjusting unit 405 may adjust the control potential V ctl (or the additional potential V add ) applied to the movable conductor 22e in order to adjust the size or width of the ion beam by adjusting the extraction electric field distribution in the vicinity of the first aperture OP1 through which the first ion beam is extracted from the ion _{source 20.} As described above, the control potential V _ctl higher than the third reference potential V _gnd is applied to the movable conductor 22e.

The beam size adjusting unit 405 may adjust the second suppression potential V _sup2 applied to the second suppression electrodes 24 e and/or 24 f to adjust the size or width of the ion beam.

The beam size adjustment unit 405 may adjust the size or width of the first ion beam based on the phase space distribution of the second ion beam measured by the phase space distribution measurement unit 407. An example of the phase space distribution measurement unit 407 is the angle measurement device provided in the beam profiler 46 described above. This phase space distribution measurement unit 407 measures the phase space distribution of the second ion beam downstream of the mass analysis slit 24b, which serves as the first separation aperture. A beam size estimation unit 408 may be provided that estimates the size or width of the first ion beam in the deflection direction (x direction) at the position of the mass analysis slit 24b based on the phase space distribution of the second ion beam measured by the phase space distribution measurement unit 407. In this case, the beam size adjustment unit 405 may adjust the size or width of the first ion beam while referring to the size or width of the first ion beam estimated by the beam size estimation unit 408.

In addition to or instead of the beam size adjustment unit 405, the ion extraction device according to this embodiment may include an aperture width adjustment unit 409 that adjusts the aperture width of the mass analysis slit 24b, which serves as the first separation aperture, in the deflection direction (x direction) by the mass analysis magnet device 24a, which serves as the first beam deflection device. The aperture width adjustment unit 409 may adjust the aperture width of the mass analysis slit 24b in the deflection direction, for example, in accordance with the difference between the central orbits of the desired ions DI and the modified ions MI in the deflection direction calculated by the trajectory calculation unit 404, and the size or width of the ion beam in the deflection direction measured by the first beam current measurement device 406. Specifically, the aperture width adjustment unit 409 adjusts the aperture width of the mass analysis slit 24b so that the beam around the central orbit of the desired ions DI can pass through the mass analysis slit 24b, and so that the beam around the central orbit of the modified ions MI cannot pass through the mass analysis slit 24b.

A second beam deflection device 410 may be provided downstream of the mass analysis slit 24b serving as the first separation aperture, which deflects the second ion beam by applying an electric field or magnetic field. Examples of the second beam deflection device 410 include the aforementioned beam scanning unit 28 (Figure 2, etc.) and AEF electrode pair 34a, 34b (Figure 1, etc.). The deflection direction of the second ion beam by the second beam deflection device 410 may intersect the direction of travel of the second ion beam (z direction) and the deflection direction of the first ion beam by the mass analysis magnet device 24a serving as the first beam deflection device (x direction), as in the beam scanning unit 28, or may be substantially the same as the deflection direction of the first ion beam by the mass analysis magnet device 24a serving as the first beam deflection device (x direction), as in the AEF electrode pair 34a, 34b. The second beam deflection device 410 adjusts the electric field or magnetic field applied to the second ion beam, for example, so that the central trajectory of the desired ions DI calculated by the trajectory calculation unit 404 becomes the desired central trajectory (i.e., so that the desired ions DI pass through the desired trajectory).

Downstream of the second beam deflection device 410 (beam scanning unit 28 and/or AEF electrode pair 34a, 34b), an energy analysis slit 34c (see FIG. 1, etc.) may be provided as a second separation aperture that separates and passes desired ions DI and modified ions MI in accordance with the electric or magnetic field. A second beam current measurement device 411 that measures the beam currents of the desired ions DI and modified ions MI may be provided downstream of the energy analysis slit 34c. Examples of the second beam current measurement device 411 include the tuning cups 38a to 38d described above. The second beam current measurement device 411 may measure the ratio of the beam currents of the desired ions DI and modified ions MI. The ion irradiation prohibition unit 412 prohibits irradiation of the wafer with the second ion beam if the ratio of the beam currents of the desired ions DI and modified ions MI measured by the second beam current measurement device 411 is outside the allowable range.

If the ratio of the beam currents of the desired ions DI and the modified ions MI measured by the second beam current measuring device 411 is within the range requiring adjustment, the beam size adjustment unit 405 may adjust the size or width of the first ion beam at the position of the mass analysis slit 24b as the first separation aperture.

If the ratio of the beam currents of the desired ions DI and the modified ions MI measured by the second beam current measuring device 411 is within the range requiring adjustment, the beam shaping unit 26 or other electric field application device may adjust the electric field applied to the ion beam. This electric field application device is preferably provided between the mass analysis magnet device 24a as the first beam deflection device and the beam scanning unit 28 and/or AEF electrode pair 34a, 34b as the second beam deflection device 410, so as to apply an electric field that prevents the transport of the modified ions MI.

Some aspects of the present disclosure are as follows:

(Aspect 1)
an ion source for generating a plasma containing desired ions;
an extraction unit that extracts ions including the desired ions from a first opening in the ion source to generate an ion beam;
an implantation processing chamber for irradiating the wafer with the ion beam;
Equipped with
The extraction unit is configured as follows, from downstream to upstream in the traveling direction of the ion beam:
a reference electrode having a second opening through which the ion beam passes and to which a reference potential is applied;
a suppression electrode having a third opening through which the ion beam passes and to which a suppression potential lower than the reference potential is applied;
a movable conductor including a fourth opening through which the ion beam passes, the movable conductor having a variable distance from the first opening in the traveling direction;
Equipped with
Ion implantation equipment.

(Aspect 2)
2. The ion implantation apparatus according to claim 1, wherein the first opening, the second opening, the third opening, and the fourth opening are slits elongated in the same direction.

(Aspect 3)
the ion beam passes through the first opening, the fourth opening, the third opening, and the second opening in this order;
a distance between the first opening and the fourth opening is controlled so that the ion beam has a desired phase space distribution when irradiated onto the wafer.
3. The ion implantation apparatus according to claim 1 or 2.

(Aspect 4)
an extraction potential higher than the reference potential is applied to the ion source;
a control potential, which is a potential between the extraction potential and the reference potential, is applied to the movable conductor in order to control a phase space distribution of the ion beam extracted from the second opening.
3. The ion implantation apparatus according to claim 1 or 2.

(Aspect 5)
3. The ion implantation apparatus according to aspect 1, wherein the distance between the suppression electrode and the reference electrode in the direction of travel is constant.

(Aspect 6)
3. The ion implantation apparatus according to claim 1, wherein the distance between the movable conductor and the suppression electrode in the traveling direction is variable.

(Aspect 7)
3. The ion implantation apparatus according to claim 1, wherein the distance between the first opening and the fourth opening in the traveling direction is controlled in accordance with the state of the ion source so that the ion beam has a desired phase space distribution when irradiated onto the wafer.

(Aspect 8)
3. The ion implantation apparatus according to claim 1, further comprising a phase space distribution measuring device downstream of the reference electrode for measuring a phase space distribution of the ion beam.

(Aspect 9)
The ion implantation apparatus of aspect 8, wherein at least one of the distance between the first opening and the fourth opening in the propagation direction and the control potential applied to the movable conductor is controlled according to the phase space distribution of the ion beam measured by the phase space distribution measuring device.

(Aspect 10)
3. The ion implantation apparatus according to aspect 1 or 2, further comprising an ion source status acquisition unit that acquires an apparatus parameter that reflects a status of the ion source.

(Aspect 11)
11. The ion implantation apparatus according to claim 10, wherein the apparatus parameters are at least one of a gas species, a gas flow rate, a vaporizer temperature, an arc current, an arc voltage, a source magnet current, which are set as parameters of the ion source, an effective extraction current which is a total amount of charge carried per unit time by the ion group including the desired ions extracted from the ion source, and a beam current of the ion beam irradiated onto the wafer.

(Aspect 12)
11. The ion implantation apparatus according to claim 10, wherein at least one of the distance between the first opening and the fourth opening in the traveling direction and the control potential applied to the movable conductor is controlled according to the apparatus parameters acquired by the ion source state acquisition unit.

(Aspect 13)
3. The ion implantation apparatus according to claim 1, further comprising an electrical information acquiring unit that acquires a potential difference between an extraction potential applied to the ion source and a control potential applied to the movable conductor, and an effective extraction current that is the total amount of charge carried per unit time by the group of ions including the desired ions extracted from the ion source.

(Aspect 14)
The ion implantation apparatus of aspect 13, wherein at least one of the distance between the first opening and the fourth opening in the traveling direction and the control potential applied to the movable conductor is controlled according to the potential difference and the effective extraction current acquired by the electrical information acquisition unit.

(Aspect 15)
3. The ion implanter of claim 1, wherein the same potential is applied to the ion source and the movable conductor.

(Aspect 16)
3. The ion implanter according to claim 1, wherein the fourth opening is larger in size than the first opening.

(Aspect 17)
an ion source for generating a plasma containing desired ions;
an extraction unit that extracts ions including the desired ions from a first opening in the ion source to generate an ion beam;
Equipped with
The extraction unit is configured as follows, from downstream to upstream in the traveling direction of the ion beam:
a reference electrode having a second opening through which the ion beam passes and to which a reference potential is applied;
a suppression electrode having a third opening through which the ion beam passes and to which a suppression potential lower than the reference potential is applied;
a movable conductor including a fourth opening through which the ion beam passes, the movable conductor having a variable distance from the first opening in the traveling direction;
Equipped with
Ion extraction device.

(Aspect 18)
an ion source for generating a plasma containing desired ions;
an extraction unit that extracts ions including the desired ions from the ion source to generate a first ion beam;
a first beam deflection device that deflects the first ion beam by applying a magnetic field;
a first separation aperture for passing the desired ions included in the first ion beam deflected by the first beam deflection device;
a potential difference setting unit that sets a potential difference between a first region that is at least a part between the outlet of the extraction unit and the inlet of the first beam deflection device, and a second region that is at least a part between the inlet and the outlet of the first beam deflection device;
an implantation processing chamber for irradiating a wafer with a second ion beam containing the desired ions that has passed through the first separation opening;
Equipped with
the potential difference is set so that modified ions generated by at least one of decomposition and charge conversion of a portion of the ions in the first ion beam passing through the first region and the desired ions have different central orbits in the second region, and at least some of the modified ions cannot pass through the first separation opening.
Ion implantation equipment.

(Aspect 19)
19. The ion implantation apparatus according to aspect 18, wherein the potential difference setting unit applies a first reference potential to the first region and applies a first bias potential different from the first reference potential to the second region.

(Aspect 20)
19. The ion implantation apparatus according to aspect 18, wherein the potential difference setting unit applies a second reference potential to the second region and applies a second bias potential different from the second reference potential to the first region.

(Aspect 21)
21. The ion implanter of any one of aspects 18 to 20, further comprising a first beam current measurement device that measures a size of the first ion beam in a direction of deflection by the first beam deflection device.

(Aspect 22)
22. The ion implantation apparatus of claim 21, wherein the first beam current measurement device is provided downstream of the first separation opening and measures the beam current of the second ion beam while changing the magnetic field applied by the first beam deflection device.

(Aspect 23)
22. The ion implanter of aspect 21, wherein the first beam current measurement device is provided upstream of the first separation opening and measures the beam current of the first ion beam while moving in the deflection direction.

(Aspect 24)
22. The ion implanter of claim 21, wherein the first separation opening has a variable opening width in the deflection direction.

(Aspect 25)
25. The ion implantation apparatus of claim 24, wherein the aperture width is adjusted according to the difference in the central orbits of the desired ions and the modified ions in the direction of deflection by the first beam deflection device at the position of the first separation aperture and the size of the first ion beam in the direction of deflection.

(Aspect 26)
21. The ion implantation apparatus according to any one of aspects 18 to 20, further comprising a trajectory calculation unit that calculates the central trajectories of the desired ions and the modified ions based on the potential difference set by the potential difference setting unit.

(Aspect 27)
27. The ion implantation apparatus according to aspect 26, wherein the trajectory calculation unit calculates a difference between the central trajectories of the desired ions and the modified ions in a deflection direction by the first beam deflector at the position of the first separation opening.

(Aspect 28)
21. The ion implantation apparatus according to any one of aspects 18 to 20, further comprising a beam size adjustment unit that adjusts a size of the first ion beam in a direction of deflection by the first beam deflector at the position of the first separation opening.

(Aspect 29)
29. The ion implantation apparatus according to aspect 28, wherein the beam size adjuster adjusts an extraction electric field distribution in the vicinity of a first opening through which the first ion beam is extracted from the ion source.

(Aspect 30)
a first beam current measuring device that measures a size of the first ion beam in the deflection direction;
the beam size adjustment unit adjusts the size while referring to the size measured by the first beam current measurement device.
29. The ion implantation apparatus of claim 28.

(Aspect 31)
The extraction unit is configured to:
a reference electrode having a second opening through which the first ion beam passes and to which a third reference potential is applied;
a first suppression electrode having a third opening through which the first ion beam passes and to which a first suppression potential lower than the third reference potential is applied;
Equipped with
the beam size adjusting unit adjusts the distance between the first opening in the ion source and the first suppression electrode.
30. The ion implantation apparatus according to aspect 29.

(Aspect 32)
The extraction unit is configured to:
a reference electrode having a second opening through which the first ion beam passes and to which a third reference potential is applied;
a first suppression electrode having a third opening through which the first ion beam passes and to which a first suppression potential lower than the third reference potential is applied;
a conductor having a fourth opening through which the first ion beam passes, the conductor having a variable distance from the ion source to a first opening through which the first ion beam is extracted;
Equipped with
the beam size adjusting unit adjusts the distance between the first opening in the ion source and the conductor.
29. The ion implanter according to aspect 28.

(Aspect 33)
The extraction unit is configured to:
a reference electrode having a second opening through which the first ion beam passes and to which a third reference potential is applied;
a first suppression electrode having a third opening through which the first ion beam passes and to which a first suppression potential lower than the third reference potential is applied;
a conductor having a fourth opening through which the first ion beam passes, the conductor having a control potential higher than the third reference potential applied thereto;
Equipped with
The beam size adjustment unit adjusts the control potential.
29. The ion implantation apparatus of claim 28.

(Aspect 34)
a second suppression electrode is provided at at least one of an entrance and an exit of the first beam deflection device, the second suppression electrode having a fifth opening through which the first ion beam passes and to which a second suppression potential lower than the potential of the second region is applied;
the beam size adjusting unit adjusts the second suppression potential.
29. The ion implantation apparatus of claim 28.

(Aspect 35)
29. The ion implanter of aspect 28, further comprising a second beam deflection device downstream of the first separation aperture, the second beam deflection device being configured to deflect the second ion beam by applying an electric or magnetic field thereto.

(Aspect 36)
36. The ion implanter of claim 35, wherein a direction of deflection of the second ion beam by the second beam deflection device intersects a direction of travel of the second ion beam and a direction of deflection of the first ion beam by the first beam deflection device.

(Aspect 37)
36. The ion implanter of claim 35, wherein the second beam deflection device adjusts an electric or magnetic field applied to the second ion beam so that the desired ions follow a predetermined trajectory.

(Aspect 38)
a second separation opening is provided downstream of the second beam deflection device, which separates the desired ions and the modified ions in accordance with the electric field or the magnetic field and allows them to pass;
a second beam current measuring device is provided downstream of the second separation opening to measure the beam currents of the desired ions and the modified ions;
36. The ion implantation apparatus according to aspect 35.

(Aspect 39)
The ion implantation apparatus of aspect 38 further comprises an ion irradiation prohibition unit that prohibits irradiation of the second ion beam onto the wafer when the ratio of the beam current of the desired ion and the modified ion measured by the second beam current measuring device is outside an acceptable range.

(Aspect 40)
An ion implantation apparatus as described in aspect 38, wherein when the ratio of the beam current of the desired ion and the modified ion measured by the second beam current measuring device is within a range requiring adjustment, the beam size adjusting unit adjusts the size of the first ion beam at the position of the first separation opening.

(Aspect 41)
an electric field application device is provided between the first beam deflection device and the second beam deflection device, the electric field application device applying an electric field to hinder the transport of the metamorphic ions;
When the ratio of the beam currents of the desired ions and the modified ions measured by the second beam current measuring device is within a range requiring adjustment, the electric field applying device adjusts the electric field to be applied.
39. The ion implantation apparatus of claim 38.

(Aspect 42)
29. The ion implanter of aspect 28, further comprising a phase space distribution measurer downstream of the first separation aperture for measuring a phase space distribution of the second ion beam.

(Aspect 43)
43. The ion implantation apparatus of claim 42, further comprising a beam size estimation unit that estimates the size of the first ion beam in the deflection direction at the position of the first separation aperture based on the phase space distribution of the second ion beam measured by the phase space distribution measurement device.

(Aspect 44)
43. The ion implantation apparatus according to aspect 42, wherein the beam size adjuster adjusts the size of the first ion beam based on the phase space distribution of the second ion beam measured by the phase space distribution measurement device.

(Aspect 45)
an ion source for generating a plasma containing desired ions;
an extraction unit that extracts ions including the desired ions from the ion source to generate a first ion beam;
a first beam deflection device that deflects the first ion beam by applying a magnetic field;
a first separation aperture for passing the desired ions included in the first ion beam deflected by the first beam deflection device;
a potential difference setting unit that sets a potential difference between a first region that is at least a part between the outlet of the extraction unit and the inlet of the first beam deflection device, and a second region that is at least a part between the inlet and the outlet of the first beam deflection device;
Equipped with
the potential difference is set so that modified ions generated by at least one of decomposition and charge conversion of a portion of the ions in the first ion beam passing through the first region and the desired ions have different central orbits in the second region, and at least some of the modified ions cannot pass through the first separation opening.
Ion extraction device.

The present disclosure has been described above with reference to the above-mentioned embodiments, but the present disclosure is not limited to the above-mentioned embodiments, and the configurations of the embodiments may be combined or substituted as appropriate. Furthermore, based on the knowledge of those skilled in the art, it is possible to rearrange the combinations and processing orders in the embodiments as appropriate, and to make various design changes and other modifications to the embodiments, and embodiments to which such rearrangements and modifications have been made may also be included within the scope of the ion implantation apparatus and ion extraction apparatus according to the present disclosure.

Embodiments of the present disclosure may take the form of a computer program including one or more computer-readable sequences describing a method of the present disclosure, or may take the form of a non-transitory, tangible recording medium (e.g., non-volatile memory, magnetic tape, magnetic disk, or optical disk) on which such a computer program is stored. A processor may implement a method of the present disclosure by executing such a computer program.

This disclosure relates to an ion implantation device and an ion extraction device.

10 ion implantation device, 14 implantation processing chamber, 20 ion source, 20c front slit, 22 extraction section, 22a suppression electrode, 22b reference electrode, 22e movable conductor, 22f extension mechanism, 22g housing, 24 mass analysis section, 24a mass analysis magnet device, 24b mass analysis slit, 24e second suppression electrode, 24f second suppression electrode, 34 energy analysis section, 34c energy analysis slit, 38 beam stopper, 46 beam profiler, 100 angle measurement device, 200 angle measurement measurement device, 300 angle measurement device, 401 ion source status acquisition unit, 402 electrical information acquisition unit, 403 potential difference setting unit, 404 trajectory calculation unit, 405 beam size adjustment unit, 406 first beam current measurement unit, 407 phase space distribution measurement device, 408 beam size estimation unit, 409 aperture width adjustment unit, 410 second beam deflection device, 411 second beam current measurement device, 412 ion irradiation inhibition unit, OP1 first aperture, OP2 second aperture, OP3 third aperture, OP4 fourth aperture, OP5 fifth aperture, R1 first region, R2 second region.

Claims (17)

an ion source for generating a plasma containing desired ions;
an extraction unit that extracts ions including the desired ions from a first opening in the ion source to generate an ion beam;
an implantation processing chamber for irradiating the wafer with the ion beam;
Equipped with
The extraction unit is configured as follows, from downstream to upstream in the traveling direction of the ion beam:
a reference electrode having a second opening through which the ion beam passes and to which a reference potential is applied;
a suppression electrode having a third opening through which the ion beam passes and to which a suppression potential lower than the reference potential is applied;
a movable conductor including a fourth opening through which the ion beam passes, the movable conductor having a variable distance from the first opening in the traveling direction;
Equipped with
Ion implantation equipment. The ion implantation device of claim 1, wherein the first opening, the second opening, the third opening, and the fourth opening are elongated slits extending in the same direction. the ion beam passes through the first opening, the fourth opening, the third opening, and the second opening in this order;
a distance between the first opening and the fourth opening is controlled so that the ion beam has a desired phase space distribution when irradiated onto the wafer.
3. The ion implantation apparatus according to claim 1. an extraction potential higher than the reference potential is applied to the ion source;
a control potential, which is a potential between the extraction potential and the reference potential, is applied to the movable conductor in order to control a phase space distribution of the ion beam extracted from the second opening.
3. The ion implantation apparatus according to claim 1. The ion implantation device of claim 1 or 2, wherein the distance between the suppression electrode and the reference electrode in the direction of travel is constant. The ion implantation device described in claim 1 or 2, wherein the distance between the movable conductor and the suppression electrode in the traveling direction is variable. An ion implantation apparatus according to claim 1 or 2, wherein the distance between the first opening and the fourth opening in the traveling direction is controlled in accordance with the state of the ion source so that the ion beam has a desired phase space distribution when irradiated onto the wafer. The ion implantation apparatus of claim 1 or 2, wherein a phase space distribution measuring device for measuring the phase space distribution of the ion beam is provided downstream of the reference electrode. The ion implantation device of claim 8, wherein at least one of the distance between the first opening and the fourth opening in the propagation direction and the control potential applied to the movable conductor is controlled in accordance with the phase space distribution of the ion beam measured by the phase space distribution measurement device. The ion implantation device according to claim 1 or 2, further comprising an ion source status acquisition unit that acquires device parameters reflecting the status of the ion source. The ion implantation apparatus of claim 10, wherein the apparatus parameters are at least one of the gas species, gas flow rate, vaporizer temperature, arc current, arc voltage, source magnet current, which are set as parameters of the ion source, the effective extraction current which is the total amount of charge carried per unit time by the ion group including the desired ions extracted from the ion source, and the beam current of the ion beam irradiated onto the wafer. The ion implantation device according to claim 10, wherein at least one of the distance between the first opening and the fourth opening in the traveling direction and the control potential applied to the movable conductor is controlled in accordance with the device parameters acquired by the ion source state acquisition unit. The ion implantation device according to claim 1 or 2, further comprising an electrical information acquisition unit that acquires the potential difference between the extraction potential applied to the ion source and the control potential applied to the movable conductor, and the effective extraction current, which is the total amount of charge carried per unit time by the group of ions, including the desired ions, extracted from the ion source. The ion implantation device of claim 13, wherein at least one of the distance between the first opening and the fourth opening in the traveling direction and the control potential applied to the movable conductor is controlled in accordance with the potential difference and the effective extraction current acquired by the electrical information acquisition unit. The ion implantation apparatus of claim 1 or 2, wherein the same potential is applied to the ion source and the movable conductor. The ion implantation apparatus of claim 1 or 2, wherein the size of the fourth opening is larger than the size of the first opening. an ion source for generating a plasma containing desired ions;
an extraction unit that extracts ions including the desired ions from a first opening in the ion source to generate an ion beam;
Equipped with
The extraction unit is configured as follows, from downstream to upstream in the traveling direction of the ion beam:
a reference electrode having a second opening through which the ion beam passes and to which a reference potential is applied;
a suppression electrode having a third opening through which the ion beam passes and to which a suppression potential lower than the reference potential is applied;
a movable conductor including a fourth opening through which the ion beam passes, the movable conductor having a variable distance from the first opening in the traveling direction;
Equipped with
Ion extraction device.