JP7583425B2 - Stage device and semiconductor manufacturing device - Google Patents

Description

The present invention relates to a stage device for microfabrication and a semiconductor manufacturing device equipped with the stage device.

A structure has been disclosed in which a holder for holding a substrate is supported by a rolling bearing in a substrate processing apparatus (see Patent Document 1). In this structure, the holder is connected to a ground potential by a grounding part. One end of the grounding part is connected to a conductive path part, and the other end of the grounding part is connected to a ground potential. It has also been described that a grounding brush or a conductive ionic liquid is used for the grounding part.

JP 2017-183389 A

In addition to the above technologies, stage devices used in semiconductor manufacturing equipment and the like sometimes use air bearings that levitate the pedestal relative to the base and linear motors that drive the pedestal in order to precisely move the workpiece placed on the pedestal. Using air bearings means that the pedestal and base are not in contact with each other, but wiring to prevent static electricity from building up on the pedestal, such as a grounding brush, is required, so the pedestal is not completely non-contact. If there is contact, friction will occur when the pedestal moves, making precise control difficult, and there is also the risk of wear powder being generated. Furthermore, if the pedestal is levitated, heat from the pedestal cannot be dissipated to the base.

The present invention aims to provide a high-precision stage device and a semiconductor manufacturing device equipped with the stage device, while ensuring non-contact electrical and thermal conductivity between the pedestal and the base, thereby suppressing charging of the pedestal and improving cooling performance.

The stage device for microfabrication according to the first aspect has a base, a pedestal provided with a first gap between the base and the pedestal, and a moving means for moving the pedestal relative to the base, and an ionic liquid having electrical conductivity and thermal conductivity is disposed in the first gap.

In this stage device, a first gap is provided between the pedestal and the base, and an electrically conductive ionic liquid is placed in the first gap, ensuring lubrication between the pedestal and the base. This allows the pedestal to be moved smoothly and with high precision for fine processing. Furthermore, by grounding the base, static electricity that builds up on the pedestal as it moves can be transferred to the base by the electrical conductivity of the ionic liquid and removed. Furthermore, heat generated by the movement of the pedestal can be transferred to the base by the thermal conductivity of the ionic liquid and dissipated.

In a second aspect, in the stage device according to the first aspect, the moving means is provided on the base and has a flow path through which the ionic liquid passes and leads to the first gap, and a control means for controlling the amount of movement of the pedestal by adjusting the amount or pressure of the ionic liquid passed through the flow path.

In this stage device, the movement of the base can be controlled with high precision by adjusting the amount or pressure of the ionic liquid using a control means.

In a third aspect, in the stage device according to the first or second aspect, the moving means moves the base at least in a horizontal direction.

In this stage device, the control means controls the amount or pressure of the ionic liquid, allowing the pedestal to be moved horizontally with high precision. When this stage device is used in semiconductor manufacturing equipment, for example, it becomes possible to position the exposure position for a semiconductor wafer with high precision.

In a fourth aspect, in the stage device according to any one of the first to third aspects, the moving means moves the base at least in the vertical direction.

In this stage device, the height of the pedestal can be controlled with high precision by controlling the amount or pressure of the ionic liquid with the control means. When this stage device is used in semiconductor manufacturing equipment, for example, it becomes possible to focus the exposure means on the semiconductor wafer with high precision.

The semiconductor manufacturing apparatus according to the fifth aspect includes a stage device according to any one of the first to fourth aspects, and a semiconductor wafer is placed on the stage device.

By using the stage device, this semiconductor manufacturing device can perform processing on semiconductor wafers with high precision.

In a sixth aspect, in the semiconductor manufacturing apparatus according to the fifth aspect, an exposure means for exposing the semiconductor wafer is provided with a second gap between the exposure means and the semiconductor wafer, and an ionic liquid is placed in the second gap as a matching oil.

In this semiconductor manufacturing device, the second gap is also filled with ionic liquid, which enables index matching. In this case, by making the ionic liquid in the first gap and the ionic liquid in the second gap the same, contamination problems can be prevented even if the two ionic liquids are mixed.

The present invention provides a high-precision stage device and a semiconductor manufacturing device equipped with the stage device, while ensuring non-contact electrical and thermal conductivity between the pedestal and the base, making it possible to suppress charging of the pedestal and improve cooling.

1 is a block diagram showing an overview of a stage device according to the present embodiment. FIG. 2 is a perspective view showing a stage device on which a semiconductor wafer is placed. 3 is a cross-sectional view taken along the line 3-3 in FIG. 2. FIG. 2 is a plan view showing a state in which the pedestal is removed from the stage device. 11 is a cross-sectional view showing a schematic state in which an ionic liquid is placed in the second gap as a matching oil. FIG. FIG. 1 is a cross-sectional view showing a schematic diagram illustrating that a developer and an ionic liquid are not mixed.

Below, the embodiment of the present invention will be described with reference to the drawings. Note that components indicated with the same reference numerals in each drawing are the same components. Also, duplicated explanations and reference numerals in the embodiments described below may be omitted.

[First embodiment]
1, a semiconductor manufacturing apparatus 10 according to this embodiment has a stage device 12 for microfabrication. The stage device 12 is installed, for example, in a vacuum container (not shown) for performing various processes on a semiconductor wafer 20. The stage device 12 has a base 14, a pedestal 16, and a moving means 18, and the semiconductor wafer 20 is placed on the pedestal 16. An ionic liquid 26 having electrical conductivity and thermal conductivity is supplied and disposed in a first gap S1 between the base 14 and the pedestal 16.

(base)
1 to 4, the base 14 is formed, for example, in a rectangular shape in a plan view, and is electrically grounded. As an example, a recess 22 in which the seat 16 is disposed is formed in the center of the base 14. The recess 22 is substantially rectangular in a plan view. The four sides surrounding the recess 22 are bank portions 24. As shown in FIGS. 2 to 4, each bank portion 24 is formed with supply holes 31X, 31Y and discharge holes 32X, 32Y for the ionic liquid 26. As an example, a throttle 30 is provided in each of the supply holes 31X, 31Y.

The supply hole 31X is a hole through which the ionic liquid 26 is supplied when the base 16 is moved in the X direction. The supply hole 31Y is a hole through which the ionic liquid 26 is supplied when the base 16 is moved in the Y direction. The discharge holes 32X and 32Y are formed below the supply holes 31X and 31Y, respectively. The supply hole 31X and the discharge hole 32X, and the supply hole 31Y and the discharge hole 32Y are each formed in pairs in the longitudinal center of each bank portion 24.

The positions and number of the supply holes 31X, 31Y and the discharge holes 32X, 32Y are not limited to this, and multiple pairs of supply holes 31X, 31Y and discharge holes 32X, 32Y may be formed in the longitudinal direction of the bank portion 24. Furthermore, the supply holes 31X, 31Y and the discharge holes 32X, 32Y do not have to be arranged in pairs. Specifically, the positions of the supply holes 31X and the discharge holes 32X may be offset from each other in the Y direction. Furthermore, the positions of the supply holes 31Y and the discharge holes 32Y may be offset from each other in the X direction.

A support portion 36 is formed on the bottom 28 of the recess 22 in the base 14. This support portion 36 is a portion that supports the pedestal 16 when the ionic liquid 26 is not supplied to the first gap S1 between the base 14 and the pedestal 16 and the pedestal 16 is not floating. This support portion 36 is formed, for example, in a rectangular ridge shape smaller than the pedestal 16 (FIG. 4). A pocket 38 is formed inside the support portion 36. The pocket 38 is not limited to one location, and may be provided in multiple locations. The bottom 29 of the pocket 38 is higher than the bottom 28 of the recess 22 and lower than the support portion 36. For example, one supply hole 31Z for moving the pedestal 16 in the Z direction (up and down direction) is formed in, for example, the center of the bottom portion 29. As an example, the supply hole 31Z is provided with a throttle 34. The number of supply holes 31Z is not limited to one, and may be multiple. By supplying ionic liquid 26 to pocket 38, it is possible to lift pedestal 16 from base 14.

A recovery groove 25 is formed in an annular shape between the support portion 36 and the bank portion 24 in the recess 22. The discharge holes 32X and 32Y described above open into this recovery groove 25.

(pedestal)
The pedestal 16 is a portion on which the semiconductor wafer 20 is placed, and is sized so that at least a portion of it fits into the recess 22 of the base 14, and is, for example, substantially rectangular in plan view. In the example shown in Fig. 2, the pedestal 16 fits entirely into the recess 22. In the example shown in Fig. 3, most of the pedestal 16 fits into the recess 22, but the upper portion slightly protrudes above the bank 24. In this manner, the pedestal 16 may have a structure that allows it to float within the recess 22.

The bottom surface 16B of the base 16 is, for example, a flat surface. In addition, a pocket 40 is formed on each of the four side surfaces 16A of the base 16. The pocket 40 is not limited to being provided in one location, and may be provided in multiple locations. The above-mentioned supply holes 31X and 31Y are provided facing the pockets 40, respectively, so that the ionic liquid 26 can be supplied toward the pockets 40. In FIG. 3, it is shown that the supply hole 31Y faces the pocket 40.

The pedestal 16 is provided with a first gap S1 between it and the base 14. The first gap S1 includes a gap in the X direction, a gap in the Y direction, and a gap in the Z direction. When the ionic liquid 26 is supplied to the first gap S1, the pedestal 16 floats up from the base 14 and is configured to be out of contact with the base 14. The first gap S1 refers to the entire gap formed between the pedestal 16 and the base 14 when the pedestal 16 floats up. The pockets 38 and 40 described above also constitute the first gap S1.

The ionic liquid 26 is, for example, an ionic liquid of an ammonium salt, an imidazolium salt, or a pyridinium salt, including N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium tetrafluoroborate (DEMEBF ₄ ). In addition, an ionic liquid of a morpholinium salt, a phosphonium salt, a piperidinium salt, a pyrrolidinium salt, or a sulfonium salt may be used. A mixture of a plurality of these salts may also be used.

(Transportation)
The moving means 18 is a drive unit for moving the pedestal 16, for example, in the horizontal direction (X direction, Y direction) and the vertical direction (Z direction) relative to the base 14, and has a flow path 42 and a control means 44. The flow path 42 is a portion provided in the base 14 and communicates with the first gap S1 through which the ionic liquid 26 passes, and examples of the flow path are the above-mentioned supply holes 31X, 31Y, 31Z and discharge holes 32X, 32Y (FIGS. 2 and 3).

The control means 44 is a control device that controls the amount of movement of the base 16 by adjusting the amount or pressure of the ionic liquid 26 passed through the flow path 42. The control means 44 has, for example, an XY direction pressure adjustment element 50, a Z direction pressure adjustment element 52, a pressure supply element 54, an ionic liquid reservoir 56, and a control element 58.

The X-Y direction pressure adjustment element 50 is, for example, a pressure adjustment valve, and is connected by piping between the supply holes 31X, 31Y of the base 14 and the pressure supply element 54. The X direction pressure adjustment element and the Y direction pressure adjustment element may be provided separately. The Z direction pressure adjustment element 52 is also, for example, a pressure adjustment valve, and is connected by piping between the supply hole 31Y of the base 14 and the pressure supply element 54.

The pressure supply element 54 is, for example, a pump, and is connected by piping between the supply holes 31X, 31Y, 31Z and the ionic liquid reservoir 56. This pressure supply element 54 pressurizes the ionic liquid 26 in the ionic liquid reservoir 56 and supplies it to the X-Y direction pressure adjustment element 50 and the Z direction pressure adjustment element 52. The ionic liquid reservoir 56 is connected by piping between the discharge holes 32X, 32Y (Figures 2 and 3) of the base 14 and the pressure supply element 54, and is a container that temporarily stores the ionic liquid 26 discharged from the discharge holes 32X, 32Y.

The movement direction of the base 16 by the moving means 18 can be any combination of the X direction, Y direction, and Z direction. Therefore, the movement direction may be only the horizontal direction, or only the vertical direction (Z direction). The horizontal direction may be either one direction (X direction or Y direction) or two directions (X direction and Y direction). The movement direction may also be the X direction and Z direction, or the Y direction and Z direction.

In the semiconductor manufacturing apparatus 10 shown in FIG. 5, an exposure means 60 for exposing a semiconductor wafer 20 is provided with a second gap S2 between the exposure means 60 and the semiconductor wafer 20. An ionic liquid 46 is placed in the second gap S2 as a matching oil.

(Action)
In FIG. 1, in the stage device 12 according to this embodiment, a first gap S1 is provided between the pedestal 16 and the base 14, and an ionic liquid 26 having electrical conductivity is disposed in the first gap S1, so that lubrication between the pedestal 16 and the base 14 is ensured. Therefore, the pedestal 16 can be moved smoothly with high precision for fine processing. In addition, the base 14 is grounded, and the static electricity charged on the pedestal 16 as the pedestal 16 moves can be transferred to the base 14 by the electrical conductivity of the ionic liquid 26 to be discharged. This allows a guide mechanism in which the pedestal 16 and the base 14 are completely non-contact. Furthermore, the heat generated by the movement of the pedestal 16 can be transferred to the base 14 by the thermal conductivity of the ionic liquid 26 to be discharged.

In the stage device 12, the pressure supply element 54 pressurizes the ionic liquid 26 in the ionic liquid reservoir 56 and supplies it to the supply holes 31X, 31Y, and 31Z. The ionic liquid 26 enters the first gap S1 and causes the pedestal 16 to float from the base 14. Excess ionic liquid 26 is collected in the ionic liquid reservoir 56 through the collection groove 25 and the discharge holes 32X and 32Y.

At this time, the X-Y direction pressure adjustment element 50 and the Z direction pressure adjustment element 52 can adjust the amount or pressure of the ionic liquid 26 supplied to the supply holes 31X, 31Y, and 31Z, thereby controlling the movement of the base 14 in the X direction, Y direction, and Z direction with high precision. For example, control on the order of nanometers required for semiconductor manufacturing is possible. Therefore, by using the stage device 12 in the semiconductor manufacturing apparatus 10, for example, the exposure position for the semiconductor wafer 20 can be positioned with high precision. In addition, by controlling the height of the pedestal 16, it is possible to focus the exposure means 60 (FIG. 6) on the semiconductor wafer 20 with high precision. In addition, since the inclination of the pedestal 16 can also be controlled, the attitude of the semiconductor wafer 20 can be controlled even if there is variation in the semiconductor wafer 20. In this way, the semiconductor manufacturing apparatus 10 using the stage device 12 can perform processing on the semiconductor wafer 20 with high precision.

In the semiconductor manufacturing apparatus 10, the inside of the processing chamber is often evacuated, so that the stage device 12 corresponding to the vacuum is required, and oil or water that generates outgas in a vacuum cannot be used in the stage device 12. In this embodiment, the ionic liquid 26 that does not vaporize even in an ultra-high vacuum environment and generates less outgas than oil or water is used for lubrication of the pedestal 16. The outgas partial pressure is, for example, less than 10 ⁻⁹ Pa. Therefore, the stage device 12 can be used in an ultra-high vacuum environment. Even if outgassing occurs in an ultra-high vacuum environment, it is easy to predict where the outgas came from. Furthermore, since a vacuum seal is not required, the configuration is simplified and the device can be made smaller. When the mechanism is driven in an ultra-high vacuum, a vacuum degree of 10 ⁻⁵ Pa or less can be maintained.

In the example shown in FIG. 5, the second gap S2 is also filled with ionic liquid 26, thereby enabling index matching. In this case, by making the ionic liquid 26 in the first gap S1 and the ionic liquid 26 in the second gap S2 the same quality, it is possible to prevent contamination problems even if the two ionic liquids 26 are mixed together.

In FIG. 6, even if the developer 62 applied to the semiconductor wafer 20 flows onto the pedestal 16 or base 14 during the semiconductor manufacturing process, the developer 62 does not mix with the ionic liquid 26, and therefore the developer 62 does not penetrate into the first gap S1 between the pedestal 16 and base 14. Therefore, changes in the properties of the ionic liquid 26 can be suppressed.

As described above, according to this embodiment, it is possible to provide a highly accurate stage device 12 and a semiconductor manufacturing device 10 equipped with the stage device 12. In addition, it is possible to ensure non-contact electrical conductivity and thermal conductivity between the pedestal 16 and the base 14, thereby making it possible to suppress charging of the pedestal 16 and improve cooling performance.

[Other embodiments]
An example of an embodiment of the present invention has been described above, but the embodiment of the present invention is not limited to the above, and it goes without saying that various modifications can be made without departing from the spirit and scope of the present invention.

10 Semiconductor manufacturing apparatus 12 Stage device 14 Base 16 Pedestal 18 Moving means 20 Semiconductor wafer 26 Ionic liquid 31X Supply hole (flow path)
31Y Supply hole (flow path)
31Z Supply hole (flow path)
32X Discharge hole (flow path)
32Y Discharge hole (flow path)
42 Flow path 44 Control means 46 Ionic liquid (second gap)
60 Exposure means S1 First gap S2 Second gap

Claims (4)

A base and
A pedestal provided with a first gap between the pedestal and the base portion;
a moving means for moving the pedestal relative to the base,
an ionic liquid having electrical and thermal conductivity is disposed in the first gap;
The moving means is a stage device for micro-machining that has a flow path provided on the base and leading to the first gap through which the ionic liquid passes, and a control means that controls the amount of movement of the base by adjusting the amount or pressure of the ionic liquid passed through the flow path. The stage device according to claim 1, wherein the moving means moves the base at least in a horizontal direction. The stage device according to claim 1 or 2, wherein the moving means moves the base at least in the vertical direction. A base and
A pedestal provided with a first gap between the pedestal and the base portion;
a moving means for moving the pedestal relative to the base,
a stage device for micro-machining, the stage device including an ionic liquid having electrical conductivity and thermal conductivity disposed in the first gap;
A semiconductor wafer is placed on the stage device,
an exposure means for exposing the semiconductor wafer to light is provided with a second gap between the exposure means and the semiconductor wafer;
A semiconductor manufacturing apparatus in which an ionic liquid is placed in the second gap as a matching oil.