JP2006140053A - Ion implantation apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ion implantation apparatus that enables easy adjustment of the parallelism of an ion beam, mainly when the ion beam is made incident on a substrate. <P>SOLUTION: The ion implantation apparatus comprises an inter-pole distance control mechanism 20 capable of changing one or both of an inner inter-pole distance Di and an outer inter-pole distance Do of a parallelizing electromagnet 10. The inter-pole distance control mechanism 20 comprises: a cylindrical rotating shaft 22 provided at a joint, between an upper pole 12 and a lower pole 14 of the parallelizing electromagnet 10 so that the upper pole 12 is pivotally rotatable, with respect to the lower pole 14; and a bolt 24 that joints the upper pole 12 and the lower pole 14 of the parallelizing electromagnet 10 to each other, and that makes the inter-pole distances Di and Do adjustable. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ion implantation apparatus, and in particular, an ion implantation apparatus that can easily adjust the parallelism of an ion beam when incident on a substrate, and even when the eccentric center of a scanner and the focal position of a collimating electromagnet deviate from each other. The present invention relates to an easily adjustable ion implantation apparatus.

Various types of ion implantation apparatuses for accelerating or decelerating ions from an ion source to a desired energy and injecting the ions into a solid surface such as a semiconductor have been put to practical use (see Patent Document 1).
Hereinafter, an example of a conventional ion implantation apparatus will be described with reference to FIG.
FIG. 8 is a plan view showing a schematic configuration of a conventional ion implantation apparatus.

As shown in FIG. 8, the main configuration of the ion implantation apparatus 100 includes an ion source 110, a mass separator 120, a mass separation slit 130, an acceleration / deceleration tube 140, a quadrupole lens 150, a scanner 160, and a collimator 170. is there.
In the figure, reference numeral 180 denotes a substrate serving as a target for implanting ions arranged in an end station (not shown).
The BM is an ion that travels around a central axis (hereinafter also referred to as an “optical axis”), but may be referred to as an “ion beam” or “beam” hereinafter.

In the following, supplementary explanation will be given sequentially on each of the main components of the ion implantation apparatus 100.
First, the ion source 110 is an apparatus that generates ions by stripping electrons from atoms and molecules, and draws out ions in the ion source 110 by applying a high voltage to a drawing port (not shown).

The mass separator 120 generates a magnetic field and / or an electric field by utilizing the property that charged particles such as ions and electrons are deflected in the magnetic field or electric field, and the ion species to be injected into the substrate 180. It is a device for specifying.
FIG. 8 shows a mass separator 120 of a type that selects ions BM by the action of a magnetic field.

The acceleration / deceleration tube 140 is a device for accelerating or decelerating a desired ion species that has passed through the mass separation slit 130, but as shown in FIG. By applying an equal high voltage to the electrodes, the ion beam BM is accelerated or decelerated to a desired implantation energy by the action of an electrostatic field.
The reason why the accelerating / decelerating tube 140 has an axisymmetric structure is that manufacture is easy.

The quadrupole lens 150 is often installed between the acceleration / deceleration tube 140 and the scanner 160 as shown in FIG. 8 in order to adjust the beam spot shape of the ion beam BM on the substrate 180. .
The quadrupole lens 150 has a function of converging the ion beam BM in a plane perpendicular to the traveling direction thereof, similarly to the case where the optical convex lens converges light.

The scanner 160 generates a uniform external electric field in a direction orthogonal to the traveling direction of the ion beam BM, and controls the ion deflection angle by changing the polarity and intensity of the electric field, as shown in FIG. Then, the ions BM are scanned at a desired position on the implantation surface of the substrate 180 to be uniformly implanted.
In the case shown in FIG. 8, scanning is performed at a high speed of about 1 kHz.

The collimator 170 utilizes the property that ions BM, which are charged particles, are deflected in a magnetic field, and suppresses the spread of the beam by the difference in the path of each ion constituting the ion beam BM, thereby forming the beam BM as a substrate. 180 is an electromagnet incident in parallel to 180.
Therefore, hereinafter, the “parallelizing device” may be referred to as “parallelizing electromagnet”.

The collimating device 170 will be supplementarily described with reference to FIGS.
FIG. 9 is a cross-sectional view of the parallelizing device 170.
As shown in FIGS. 8 and 9, the main configuration of the parallelizing device 170 mainly includes an upper magnetic pole 172, a lower magnetic pole 174, and an exciting coil 176.
Moreover, the planar shape of the upper and lower magnetic poles 172 and 174 is a sector shape, and the cross-sectional shape is an H-type electromagnet having a H-shaped gap between the upper and lower magnetic poles 172 and 174 as shown in FIG.

Next, the basic operation of the collimator 170 will be described.
In general, a sector electromagnet such as the collimating electromagnet 170 shown in FIG. 8 has a converging lens function for converging the ion beam BM.
Therefore, the ion beam that has passed through the collimator 170 depends on the scanning angle of the scanner 160 by arranging the collimator 170, which is a sector electromagnet, so that the focal position of the collimator 170 coincides with the deflection center of the scanner 160. Without a certain angle.
Therefore, by disposing the collimator 170 on the downstream side of the scanner 160 so as to have the above-described positional relationship, even if the ion beam BM is scanned, it can be injected into the substrate 180 in parallel.

Next, the basic operation of the conventional ion implantation apparatus 100 will be described with reference to FIG.
In the conventional ion implantation apparatus 100, in order to perform ion implantation with a predetermined energy at a uniform density over the entire surface of the ion BM implantation surface of the substrate 180, a predetermined energy is extracted from the ion source 110. The ion beam BM thus deflected is deflected by the mass separator 120, and only predetermined ion species are sorted by the mass separation slit 130.

The selected ion beam BM is accelerated or decelerated to a desired energy by the acceleration / deceleration tube 140, and as described above, an external electric field having a period of about 1 kHz is applied to the scanner 160, and further, parallelized by the collimator 170. Then, the scanning surface of the substrate 180 is scanned.
In the above description, the electrostatic type scanner 160 that scans the ion beam BM with an external electric field is taken up. However, the scanner 160 may be a magnetic type instead of the electrostatic type.

  The depth at which the ion BM enters the solid can be accurately controlled by the energy of the ion BM. For example, when the ion implantation apparatus 100 is started up, the dose distribution of the ion beam is monitored. By scanning the implantation surface with the ion beam BM, uniform ion implantation processing of a desired ion species can be easily performed.

JP-A-8-213339 T. Nishihashi et al. Proceedings of 1998 Int. Conf. On Ion Implantation Technology, (1999) 150-

By the way, with miniaturization of semiconductor devices, demands on the parallelism of ion beams injected into a substrate are becoming stricter in ion implantation apparatuses.
Specifically, it is desirable to maintain a parallelism of about ± 0.1 ° over the entire surface of the substrate.

On the other hand, the shape of the magnetic field distribution of the electromagnet is slightly different from the shape of the magnetic pole constituting the electromagnet, but this will be supplementarily explained with reference to FIG.
The magnetic field distribution in the axial direction of the ion beam BM of an electromagnet such as the parallel electromagnet 170 suddenly rises to the design magnetic field strength at the incident side magnetic pole end surface 170a of the ion beam BM, and suddenly reaches zero at the emission side magnetic pole end surface 170b. Rather than being lowered, the shape has a tail-like leakage magnetic field that converges gently from the design value to 0 from the inside near the magnetic pole end faces 170a and 170b.

  In general, the magnetic permeability of the magnetic material such as pure iron constituting the magnetic poles and yokes of the electromagnet has a non-linear characteristic particularly in the vicinity of the magnetic saturation, so that the shape of the magnetic field distribution described above also depends on the strength of the magnetic field. May be slightly different.

  Therefore, for these reasons, in the collimator 170, the effective end surfaces of the magnetic pole end surfaces 170a and 170b are different from the design values, and the deflection center of the scanner 160 and the focus of the collimator 170 may slightly deviate from the design values. .

Here, the above-mentioned “effective end face” will be supplementarily described.
As described above, the electromagnet has a leakage magnetic field at the magnetic pole end face, but at the design stage of the beam line, an effective magnetic end face corrected in consideration of the shape of the leakage magnetic field is calculated. It approximates a rectangular equivalent magnetic field shape that rises from the incident-side effective end face to the designed magnetic field intensity, falls to 0 at the outgoing-side effective end face, and is a uniform magnetic field between the effective end faces.
In this way, since it is well known that charged particles draw a circular or circular orbit in a uniform magnetic field, the trajectory before and after the entrance / exit of the ion beam BM in the electromagnet enters the uniform magnetic field in the electromagnet. Becomes a straight line and a circular arc in the electromagnet, and the trajectory analysis of the ion beam BM becomes very simple.

Incidentally, as described above, in the conventional ion implantation apparatus 100, the angle of the ion beam BM after passing through the collimating apparatus 170 varies slightly depending on the scanning angle, and the implantation angle changes depending on the position on the substrate 180. There is a problem.
The problem of the conventional apparatus in which the ion beam that has passed through the collimator 170 becomes non-parallel due to the fact that the effective end face of the collimator 170 is different from the design value or the strength of the magnetic field is changed is shown in FIG. I will explain.
FIG. 10 is a plan view for explaining the problem that the ion beam BM that has passed through the collimator 170 becomes non-parallel in the conventional ion implanter 100.

As shown in FIG. 10, in the collimator 170, the design value of the effective end face on the incident side of the ion beam BM is A1, and the design value of the effective end face on the exit side is B1.
On the other hand, the actual effective end face on the incident side is A2, the actual effective end face on the exit side is B2, and the deflection center in the scanner 160 is C.

Hereinafter, as described above, the magnetic field generated by the collimating electromagnet 170 rises from the incident-side effective end face A1 to the design magnetic field strength and falls from the exit-side effective end face B1 to 0, and is incident-side effective. An approximation that the designed uniform magnetic field is applied between the end face A1 and the effective end face B1 on the emission side is performed.
The same approximation is performed for the magnetic fields on the effective end faces A2 and B2 in practice.

  In this way, since the ion beam can be regarded as a circular arc trajectory from the effective end surface A1 on the incident side to the effective end surface B1 on the exit side, the trajectory of the ion beam BM created by the collimating electromagnet 170 is designed. Then, the trajectory of the ion beam BM reaching the center of the substrate 180 should be a solid line K1, and the trajectory of the ion beam BM deflected outward by the scanner 160 should be a solid line K2.

However, when the effective end face changes like the effective end faces A2 and B2 due to the reasons described above, the trajectory of the ion beam BM reaching the center of the substrate 180 becomes as indicated by the broken line K3 and is moved outward by the scanner 160. The trajectory of the deflected ion beam BM is as shown by a broken line K4.
That is, in the conventional ion implantation apparatus 100, it is shown that the angle of the ion beam after passing through the collimating electromagnet 170 changes depending on the scanning angle by the scanner 160.

By the way, the end surfaces 170a and 170b of the incident part and the emission part of the collimating electromagnet 170 are inclined or curved with respect to the ion beam BM reaching the center of the substrate 180 (in FIG. ).
However, here, for the sake of simplification, in the following, for the sake of simplicity, the incident surface of the collimating electromagnet 170 and the end surfaces 170a and 170b of the output portion of the collimating electromagnet 170 are compared with the ion beam BM that reaches the center of the substrate 180. It is considered to be vertical and is considered by linear optical theory.

The deflection angle of the ion beam reaching the center of the substrate 180 in the collimating electromagnet 170 is θ, the turning radius of the ion beam is R, and the distance from the deflection center C of the scanner 160 to the effective end face A1 of the collimating electromagnet 170 is L. If the angle formed by the ion beam BM that passes through the scanner 160 and the ion beam BM that reaches the center of the substrate 180 is δ1, the ion beam BM that passes through the collimating electromagnet 170 reaches the center of the substrate 180 and The formed angle δ2 is given by the following equation (1).

  Therefore, for example, when the deflection angle θ of the collimating electromagnet 170 is 60 ° and the turning radius R is 0.8 m, if the distance L between the deflection center C of the scanner 160 and the effective end surface A1 is 0.461 m, The angle δ2 after passing through the collimating electromagnet 170 is always 0 ° without depending on the angle δ2 after passing through the scanner 160.

However, it is assumed that the effective end faces A2 and B2 spread by ΔL = 50 mm on the incident side and the emission side, respectively.
In this case, in order for the deflection angle θ of the ion beam BM to reach the center of the substrate 180 in the collimating electromagnet 170 to coincide with the design value, the turning radius R ′ in the collimating electromagnet 170 is

R ′ = R + 2ΔL / θ (2)

Therefore, R ′ = 0.895m.

The distance between the deflection center and the effective end face is
L ′ = L−ΔL
Therefore, L ′ = 0.411 m.
As a result, the ion beam having an angle of 5 ° after passing through the scanner 160 has an angle of 0.5 ° after passing through the collimating electromagnet 170, reaching the upper limit of the requirement for parallelism described above. End up.

  As described above, in the conventional ion implantation apparatus 100, the angle of the ion beam incident on the substrate 180 because the actual effective end faces A 2 and B 2 of the collimating electromagnet 170 are different from the effective end faces A 1 and B 1 of the design value. However, there is a problem that the distance varies depending on the position on the substrate 180.

  Further, in the conventional ion implantation apparatus 100, as shown in FIG. 9, once the collimating electromagnet 170 is manufactured, the magnetic field in accordance with the ion type and energy of the ion beam BM is obtained with the exciting current amount of the exciting coil 176. For example, there is no function to adjust the magnetic field strength distribution in the radial direction, and there is a problem that no action can be taken when the effective end face is displaced.

  Further, in the conventional ion implantation apparatus 100, as shown in FIG. 8, once the scanner 160 is installed in the beam line, the effective end face of the collimating electromagnet 170 is displaced due to the above-described reason, and thus scanning is performed. There is also a problem that it is impossible to cope with the case where the center of eccentricity of the vessel 160 is deviated from the focal position of the parallel electromagnet 170.

  The present invention solves the above-described conventional problems, and an ion implantation apparatus that can easily adjust the parallelism of an ion beam when incident on a substrate, and even when the eccentric center of the scanner is out of focus with the collimating electromagnet. An object of the present invention is to provide an ion implantation apparatus that can be easily adjusted.

  In the ion implantation apparatus according to the first aspect of the present invention, ions are extracted from an ion source that generates ions, a desired ion species is selected by a mass separator, and the desired ion species is obtained by an acceleration / deceleration tube. In an ion implantation apparatus that accelerates or decelerates to energy, collimates the ions with a collimating electromagnet, and implants the desired ions into an implantation surface of a substrate such as a semiconductor wafer, an inner magnetic pole interval and an outer magnetic pole of the collimating electromagnet A magnetic pole spacing control mechanism that can change one or both of the spacings is provided, and the magnetic field strength distribution between the magnetic poles of the parallelizing electromagnet can be adjusted.

  The ion implantation apparatus according to claim 2, wherein a magnetic pole interval control mechanism that can change one or both of the inner magnetic pole interval and the outer magnetic pole interval of the parallelizing electromagnet includes an upper magnetic pole and a lower magnetic pole of the parallelizing electromagnet. A cylindrical rotating shaft provided so that the upper magnetic pole can be axially rotated with respect to the lower magnetic pole and an upper magnetic pole and a lower magnetic pole of the parallelizing electromagnet are joined to the joint, and a distance between the magnetic poles is increased. It was set as the structure provided with the 1 or 2 or more volt | bolt which can be adjusted.

  The ion implantation apparatus according to claim 3 extracts ions from an ion source that generates ions, selects a desired ion species by a mass separator, and accelerates or decelerates the ion species to a desired energy by an acceleration / deceleration tube. In an ion implanter that scans with a scanner and collimates the ions with a collimating electromagnet and implants the desired ions into the implantation surface of a substrate such as a semiconductor wafer, the axial position of the scanner is changed. A position control mechanism that can be used is provided, and the deflection center position of the scanner can be adjusted.

  The ion implantation apparatus according to claim 4, wherein the position control mechanism capable of changing the axial position of the scanner includes one or more rails arranged in parallel to a central axis direction of the ion beam, and the scanning. And a movable body that can be moved on the rail and a fixture that fixes the movable body to a desired position of the rail.

  The ion implantation apparatus according to claim 5, wherein a position control mechanism capable of changing an axial position of the scanner includes one or more rails arranged in parallel to a central axis direction of the ion beam, and the scanning. And a movable body that can move on the rail and a ball screw that is arranged in parallel to the central axis direction of the ions and that controls the position of the movable body.

Since the ion implantation apparatus of the present invention is configured as described above, it has the following excellent effects.
(1) If comprised as described in Claim 1, even after once producing the parallelizing electromagnet, the parallelism of an ion beam can be adjusted easily.

(2) When configured as described in claim 2, a magnetic pole spacing control device having a simple configuration can be obtained.

(3) With the configuration described in claim 3, the axial position of the deflection center of the scanner can be easily adjusted even after the scanner is once arranged on the beam line.

(4) When configured as described in claim 4, a position control device having a simple configuration can be provided.

(5) With the configuration as described in claim 5, it is possible to provide a position control device with a simple configuration and to easily adjust the deflection center of the scanner in real time by remote control.

First and second embodiments of the ion implantation apparatus of the present invention will be described in sequence with reference to FIGS.
First embodiment:
First, a first embodiment of an ion implantation apparatus of the present invention will be described with reference to FIGS. 1 to 3 and FIG.

FIG. 1 is a sectional view showing the main configuration of a parallelizing electromagnet used in the first embodiment of the ion implantation apparatus of the present invention.
FIG. 2 is a cross-sectional view for explaining the basic operation of the collimating electromagnet used in the first embodiment of the ion implantation apparatus of the present invention.
FIG. 3 is a plan view for explaining the basic operation of the parallelizing electromagnet used in the first embodiment of the ion implantation apparatus of the present invention.

First, the basic configuration of the ion implantation apparatus of the present embodiment will be described.
A feature of the ion implantation apparatus of the present embodiment is that the parallelization apparatus 170 is improved in the conventional ion implantation apparatus 100 shown in FIG.
Accordingly, the following description will focus on the parallelizing device used in the ion implantation apparatus of the present embodiment, and the other components are the same as those of the conventional ion implantation apparatus 100 shown in FIG. Will be omitted.

First, the basic configuration of the parallelizing electromagnet 10 used in the ion implantation apparatus of the present embodiment will be described.
As shown in FIG. 1, the parallelizing electromagnet 10 of the present embodiment includes an upper magnetic pole 12, a lower magnetic pole 14, and an excitation coil 30, and the inner magnetic pole interval Di and the outer magnetic pole interval Do of the parallelizing electromagnet 10 are changed. It is characterized by having a magnetic pole spacing control mechanism 20 that can be used.
FIG. 1 is a cross-sectional view of the collimating electromagnet 10 viewed from the upstream side. The left side is a region through which the ion beam BM deflected to the outside of the collimating electromagnet 10 by the scanner 160 passes, that is, the outer magnetic pole 16. And the right side represents the inner magnetic pole 18.
In the H-type electromagnet 10 as shown in FIG. 1, there is no clear boundary between the outer magnetic pole 16 and the inner magnetic pole 18, but the left side from the center is the outer magnetic pole 16, and the right side from the center is the inner magnetic pole 18. .

Further, the magnetic pole spacing control mechanism 20 is a cylindrical shape that is provided at the joint between the upper magnetic pole 12 and the lower magnetic pole 14 of the parallelizing electromagnet 10 so that the upper magnetic pole 12 can rotate about the lower magnetic pole 14. The rotary shaft 22 and the upper magnetic pole 12 and the lower magnetic pole 14 are joined, and one or more (2 in the drawing) bolts 24 that can adjust the distances Di and Do between the magnetic poles.
Further, as shown in FIG. 1, the left and right end portions of the joint surface between the upper magnetic pole 12 and the lower magnetic pole 14 are provided with a taper having an angle of several degrees in order to easily adjust the distances Di and Do between the magnetic poles. ing.

Next, the basic operation of the collimating electromagnet 10 according to the present embodiment will be described with reference to FIGS.
The basic operation of the collimating electromagnet 10 according to the present embodiment is characterized by controlling one or both of the inner and outer magnetic pole distances Di and Do with a bolt 24 that joins the upper magnetic pole 12 and the lower magnetic pole 14. The angle of the ion beam incident on the substrate depends on the position on the substrate because the radial effective magnetic field strength of the collimating electromagnet 10 is controlled and the actual effective end surface of the parallelizing electromagnet 10 is different from the effective end surface of the design value. It is to solve the problem of changing.
Here, the property of the electromagnet is used in which the magnetic field strength decreases as the inter-pole distances Di and Do increase, and the magnetic field strength increases as the inter-pole distances Di and Do decrease.

Next, the basic operation of the collimating electromagnet 10 according to the present embodiment will be verified with reference to FIGS. 1 to 3. It is assumed that the deflection surface of the ion beam BM in the collimating electromagnet 10 is in a horizontal plane.
FIG. 2 is a cross-sectional view of the collimating electromagnet 10 on a plane orthogonal to the optical axis (center axis) of the ion beam BM.
In FIG. 2, the magnetic pole spacing control mechanism 20 is not shown for the sake of simplicity.

First, in the parallelizing electromagnet 10, the case where the actual effective end face A2 is shifted to the outside from the designed effective end A1 will be considered with reference to FIG.
As shown in FIG. 3, the ion beam BM scanned to the outside of the collimating electromagnet 10 by the scanner 160 is emitted to the outside, and the ion beam BM scanned to the inside of the collimating electromagnet 10 is emitted at an angle to the inside. To do.

In this case, as shown in FIG. 2, the side between the lower magnetic pole 14 and the upper magnetic pole 12 of the collimating electromagnet 10 is deflected to the inside of the ion beam by the bolt 24 and the rotating shaft 22 shown in FIG. Adjust mechanically so that it becomes wider.
When the inner side of the upper magnetic pole 12 is raised so that the inner magnetic pole distance Di is larger than the outer magnetic pole distance Do, the outer magnetic field becomes relatively stronger than the inner magnetic field.

  In this state, if the magnetic field of the collimating electromagnet 10 is slightly increased so that the turning radius of the ion beam BM reaching the center of the substrate 180 is equal to the design value, the turning radius of the ion beam BM passing outside is slightly reduced. The turning radius of the ion beam BM passing through the inside is slightly increased.

As a result, the ion beam BM passing through the outer side and the ion beam BM passing through the inner side have the same angle, and ion implantation into the substrate 180 can be performed at a constant angle regardless of the position of the substrate 180.
This state is shown in FIG.
In FIG. 3, the trajectory before adjustment of the ion beam BM deflected outward by the scanner 160 is indicated by a solid line K7, and the trajectory after adjustment is indicated by a broken line K6.

  The turning radius R ″ of the collimating electromagnet 10 of the ion beam BM deflected to the outside is slightly smaller than the turning radius R ′ before adjustment, and the trajectory of the ion beam BM that has been opened to the outside is the center of the substrate 180 as designed. It can be seen that the ion beam BM is corrected so as to be parallel to the ion beam BM.

  On the contrary, when the effective end A2 of the parallelizing electromagnet 10 is shifted inward from the effective end A1 (see FIG. 10) of the design value, the interval between the lower magnetic pole 16 and the upper magnetic pole 14 is set to the outside. What is necessary is just to mechanically adjust to the direction opposite to FIG. 2 so that it may become wide on the deflected side.

  That is, the collimating electromagnet 10 of the ion implantation apparatus of the present embodiment, unlike the conventional one, can easily adjust the parallelism of the ion beam BM even after the collimating electromagnet 10 is once manufactured. it can.

Next, in the collimating electromagnet 10 of the present embodiment, the deflection angle deviation due to the change in the effective end portion, the deviation of the deflection angle, and the adjustment widths of the inner and outer magnetic pole gaps Di and Do at this time, The relationship will be described with reference to FIGS.
FIG. 4 is a cross-sectional view for explaining the relationship between the deviation of the deflection angle and the adjustment width of the gap between the magnetic poles in the parallelizing electromagnet used in the first embodiment of the ion implantation apparatus of the present invention.
FIG. 5 is a plan view for explaining the relationship between the deviation of the deflection angle and the adjustment width of the gap between the magnetic poles in the collimating electromagnet used in the first embodiment of the ion implantation apparatus of the present invention.

By the way, when the turning radius slightly changes from R to R + ΔR in the collimating electromagnet 10 as shown in FIG. 5 due to the change in the effective end, the deviation Δθ of the deflection angle is given by the following equation (3).

従って、Δθ＝０．５°、θ＝６０°とすると、ΔＤ／Ｄ＝１％となる。
ここで、図４に示す、平行化電磁石１０の端部における調整幅ΔＸとΔＤとの関係は、平行化電磁石１０の構造にも依るが、概ね、ΔＸは、磁極間ギャップＤの数％程度でよい。 Generally, since R∝1 / B (B is a magnetic flux density) and B∝1 / D (D is a gap between magnetic poles: see FIG. 4), in order to correct the deflection angle by Δθ,

Therefore, if Δθ = 0.5 ° and θ = 60 °, ΔD / D = 1%.
Here, the relationship between the adjustment widths ΔX and ΔD at the end of the parallelizing electromagnet 10 shown in FIG. 4 depends on the structure of the parallelizing electromagnet 10, but generally ΔX is about several percent of the gap D between the magnetic poles. It's okay.

Second embodiment:
First, a second embodiment of the ion implantation apparatus of the present invention will be described with reference to FIG. 8 using FIG. 6 and FIG.

FIG. 6 is a perspective view showing the main configuration of the scanner used in the second embodiment of the ion implantation apparatus of the present invention.
FIG. 7 is a cross-sectional view for explaining the basic operation of the scanner used in the second embodiment of the ion implantation apparatus of the present invention.

First, the basic configuration of the ion implantation apparatus of the present embodiment will be described.
A feature of the ion implantation apparatus of the present embodiment is that the scanner 160 is improved in the conventional ion implantation apparatus 100 of FIG.
Therefore, the following description will focus on the scanner 40 used in the ion implantation apparatus of the present embodiment, and the other components are the same as those of the conventional ion implantation apparatus 100 shown in FIG. Will be omitted.

First, the basic structure of the scanner 40 used for the ion implantation apparatus of this Embodiment is demonstrated.
As shown in FIG. 6, the scanner 40 of the present embodiment is characterized by having a position control mechanism 50 that can change the axial position of the ion beam BM of the scanner 40.

The position control mechanism 50 has one or more (2 in the drawing) rails 54 arranged in parallel to the central axis direction of the ion beam BM, the scanner main body 160 and the rail 54 on the rail 54. The movable body 52 is configured to be movable, and a fixture 56 that fixes the movable body 52 to a desired position on the rail 54.
Reference numeral 58 denotes an insulator that supports the scanner main body 160 to which a high voltage is applied.

Next, the basic operation of the scanner 40 of this embodiment will be described with reference to FIG.
The basic operation of the scanner 40 according to the present embodiment is characterized in that the deflection center of the scanner 40 is controlled by mechanically adjusting the axial position of the scanner 40, and the actual effective end face of the collimating electromagnet 170. However, this is to solve the problem that the angle of the ion beam incident on the substrate 180 changes depending on the position on the substrate 180 because the design value is different from the effective end face (see FIG. 8).

Hereinafter, the basic operation of the scanner 40 of the present embodiment will be verified with reference to FIG.
When the actual effective end face A2 of the collimating electromagnet 170 is shifted outward from the design effective end face A1 (see FIG. 10), the trajectory of the ion beam BM deflected outward at the deflection center C is as indicated by a solid line K9. Thus, the ion beam BM after passing through the collimating electromagnet 170 becomes open.

In this case, in the ion implantation apparatus of the present embodiment, the scanner 40 is moved to the upstream side, and the deflection center in the scanner 40 is moved from C to C ′ on the design value, so that ions deflected to the outside are moved. The trajectory of the beam BM is as indicated by a broken line K10, and the ion beam BM after passing through the collimating electromagnet 170 can be set to a constant angle without depending on the deflection angle by the scanner 40.
On the other hand, when the effective end face of the parallelizing electromagnet 170 is displaced inward, the scanner 40 may be moved downstream.

  That is, unlike the conventional one, the scanner 40 of the ion implantation apparatus of this embodiment can easily adjust the parallelism of the ion beam even after the scanner 40 is once arranged on the beam line. Can do.

The ion implantation apparatus of the present invention is not limited to the above embodiments, and various modifications can be made.
First, in the above embodiment, the position control mechanism of the scanner has been described as having a structure including a fixture for fixing the desired position of the rail. However, this includes a ball screw for controlling the position of the movable body. You may replace it with something.
If comprised in this way, it will become easy to adjust the deflection center of a scanner in real time, even while operating an ion implantation apparatus by operating a ball screw remotely.

  Further, the example of the ion implantation apparatus having the configuration shown in FIG. 8 has been described. However, the present invention is not necessarily applicable only to this conventional example, and the present invention can be applied to all ion implantation apparatuses including a scanner and a parallelizing electromagnet. It goes without saying.

It is sectional drawing which shows the main structures of the parallelizing electromagnet used for 1st Embodiment of the ion implantation apparatus of this invention. It is sectional drawing for demonstrating the basic operation | movement of the parallelizing electromagnet used for 1st Embodiment of the ion implantation apparatus of this invention. It is a top view for demonstrating the basic operation | movement of the parallelizing electromagnet used for 1st Embodiment of the ion implantation apparatus of this invention. In the parallelizing electromagnet used for the first embodiment of the ion implantation apparatus of the present invention, it is a sectional view for explaining the relationship between the deviation of the deflection angle and the adjustment width of the gap between the magnetic poles. FIG. 5 is a plan view for explaining the relationship between the deviation of the deflection angle and the adjustment width of the gap between the magnetic poles in the parallelizing electromagnet used in the first embodiment of the ion implantation apparatus of the present invention. It is a perspective view which shows the main structures of the scanner used for 2nd Embodiment of the ion implantation apparatus of this invention. It is sectional drawing for demonstrating the basic operation | movement of the scanner used for 2nd Embodiment of the ion implantation apparatus of this invention. It is a top view which shows schematic structure of the conventional ion implantation apparatus. It is sectional drawing of the parallelization apparatus used for the conventional ion implantation apparatus. It is a top view for demonstrating the problem that the ion beam which passed the parallelization apparatus becomes non-parallel in the conventional ion implantation apparatus.

Explanation of symbols

10: Parallelizing electromagnet (parallelizing device)
12: Upper magnetic pole 14: Lower magnetic pole 16: Outer magnetic pole 18: Inner magnetic pole 20: Magnetic pole interval control mechanism 22: Rotary shaft 24: Bolt 30: Excitation coil 40: Scanner 50: Position control mechanism 54: Rail 52: Movable body 56 : Fixing tool 100: Ion implanter 120: Mass separator 140: Acceleration / deceleration tube 180: Substrate Do: Outer magnetic pole spacing Di: Inner magnetic pole spacing

Claims (5)

Ions are extracted from an ion source that generates ions, a desired ion species is selected by a mass separator, this ion species is accelerated or decelerated to a desired energy by an acceleration / deceleration tube, and the ions are collimated by a parallelizing electromagnet. In an ion implantation apparatus for implanting the desired ions into an implantation surface of a substrate such as a semiconductor wafer,
Ion having a magnetic pole interval control mechanism that can change one or both of the inner magnetic pole interval and the outer magnetic pole interval of the collimating electromagnet, and the magnetic field strength distribution between the magnetic poles of the collimating electromagnet can be adjusted. Injection device. A magnetic pole interval control mechanism that can change one or both of the inner magnetic pole interval and the outer magnetic pole interval of the parallelizing magnet,
A cylindrical rotation shaft provided at a joint portion between the upper magnetic pole and the lower magnetic pole of the parallelizing electromagnet so that the upper magnetic pole can rotate with respect to the lower magnetic pole;
The ion implantation apparatus according to claim 1, further comprising one or more bolts that join the upper magnetic pole and the lower magnetic pole of the parallelizing electromagnet and adjust the distance between the magnetic poles. Ions are extracted from an ion source that generates ions, a desired ion species is selected by a mass separator, this ion species is accelerated or decelerated to a desired energy by an acceleration / deceleration tube, scanned by a scanner, and a collimating electromagnet In the ion implantation apparatus that collimates the ions by the above and implants the desired ions into the implantation surface of a substrate such as a semiconductor wafer,
An ion implantation apparatus comprising: a position control mechanism capable of changing an axial position of the scanner; and an adjustment of a deflection center position of the scanner. A position control mechanism capable of changing the axial position of the scanner is:
One or more rails arranged parallel to the direction of the central axis of the ion beam;
A movable body that mounts the scanner and is movable on the rail;
The ion implantation apparatus according to claim 3, further comprising a fixture that fixes the movable body to a desired position of the rail. A position control mechanism capable of changing the axial position of the scanner is:
One or more rails arranged parallel to the direction of the central axis of the ion beam;
A movable body that mounts the scanner and is movable on the rail;
The ion implantation apparatus according to claim 3, further comprising a ball screw disposed parallel to the central axis direction of the ions and controlling the position of the movable body.

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