JP7402037B2 - electrostatic chuck - Google Patents

Description

The technology disclosed herein relates to an electrostatic chuck.

For example, an electrostatic chuck is used as a holding device for holding a wafer when manufacturing semiconductors. An electrostatic chuck connects a plate-shaped member made of, for example, a ceramic material, a chuck electrode arranged inside the plate-shaped member, a base member made of, for example, a metal material, and the plate-shaped member and the base member. The wafer is attracted to the surface of the plate-shaped member (hereinafter referred to as the "attraction surface") using the electrostatic attraction generated by applying a voltage to the chuck electrode. Hold.

If the temperature of the wafer held on the suction surface of the electrostatic chuck does not reach the desired temperature, the precision of each process (film formation, etching, etc.) on the wafer may decrease. The ability to control distribution is required. Therefore, for example, by cooling by supplying a refrigerant to the refrigerant flow path formed in the base member, it is possible to control the temperature distribution of the suction surface of the plate member (and by extension, control the temperature distribution of the wafer held on the suction surface). It will be done.

In addition, in electrostatic chucks, helium gas is added to the space between the wafer and the suction surface of the plate member in order to improve the heat transfer characteristics between the plate member and the wafer and improve the controllability of the temperature distribution of the wafer. A configuration is known in which an inert gas such as the following can be supplied (see, for example, Patent Document 1). In an electrostatic chuck with such a configuration, a plurality of gas discharge holes are formed on the suction surface of the plate-shaped member, and a gas flow path communicating with the plurality of gas discharge holes is formed inside the electrostatic chuck. has been done. When an inert gas is supplied to this gas flow path, the inert gas is supplied from the plurality of gas discharge holes to the space between the wafer and the suction surface of the plate-shaped member. In order to keep the inert gas supplied to the space within the space, the suction surface of the plate-like member has a continuous wall-like protrusion (a "seal band") surrounding the plurality of gas discharge holes. ) is formed.

JP2017-157726A

In an electrostatic chuck, for example, inert gas leaks from the space between the wafer and the suction surface of the plate member due to wear of a portion of the wall-like protrusion (seal band) over time. The concentration of inert gas within the space may become non-uniform. If the concentration of the inert gas in the space becomes non-uniform, the heat transfer characteristics between the wafer and the plate member become non-uniform, resulting in a decrease in the controllability of the temperature distribution of the wafer (for example, There is a risk that the in-plane uniformity of the temperature distribution will deteriorate. Furthermore, even if there are variations in the amount of inert gas discharged from each gas discharge hole due to product variations in electrostatic chucks, etc., the above-mentioned The concentration of the inert gas in the space becomes non-uniform, and as a result, the controllability of the temperature distribution of the wafer may deteriorate. In addition, for example, in the space between the wafer and the suction surface of the plate-like member, the concentration of the inert gas in specific parts may be increased or lowered, thereby increasing the concentration of the inert gas in each part of the wafer. Although it is possible to control the temperature to a desired temperature, such control cannot be achieved with conventional electrostatic chucks. As described above, in conventional electrostatic chucks, there is room for improvement in the controllability of the inert gas concentration in the space between the wafer and the attraction surface of the plate-shaped member. There is room for improvement in the controllability of the temperature distribution of the wafer, and furthermore, there is room for improvement in the controllability of the temperature distribution of the wafer held by the electrostatic chuck.

This specification discloses a technique that can solve the above-mentioned problems.

The technology disclosed in this specification can be realized, for example, as the following form.

(1) The electrostatic chuck disclosed in this specification includes a plate-like member having a first surface and a second surface opposite to the first surface, and an interior of the plate-like member. and a chuck electrode that generates electrostatic attraction, and a third surface, the third surface being located on the second surface side of the plate member, and a cooling mechanism. a joint portion disposed between the second surface of the plate-like member and the third surface of the base member to join the plate-like member and the base member. , holding an object (for example, a wafer) on the first surface of the plate member. In this electrostatic chuck, a plurality of gas discharge holes and a continuous wall-shaped convex portion surrounding the plurality of gas discharge holes are formed on the first surface of the plate-shaped member, A gas flow path communicating with the plurality of gas discharge holes is formed inside the electrostatic chuck, and the electrostatic chuck is further provided with a gas flow path communicating with the plurality of gas discharge holes. , a discharge amount adjustment section that adjusts the amount of gas discharged from each of the gas discharge holes. According to this electrostatic chuck, since the discharge amount adjustment section is provided to adjust the amount of inert gas discharged from each gas discharge hole, the amount of inert gas discharged from each gas discharge hole is adjusted using the discharge amount adjustment section. can be adjusted. Therefore, it is possible to improve the controllability of the concentration of the inert gas at each position in the space between the object and the first surface of the plate-like member, and in turn, it is possible to improve the temperature controllability of the object. can.

For example, due to wear of a part of the wall-like convex part over time, inert gas leaks from the space between the object and the first surface of the plate-like member, and each part in the space The concentration of inert gas at a location may be non-uniform. Even in such a case, by adjusting the amount of inert gas discharged from each gas discharge hole using the discharge amount adjusting section, the non-uniformity of the concentration of the inert gas can be alleviated and eliminated. Furthermore, for example, due to product variations in electrostatic chucks, there are variations in the amount of inert gas discharged from each gas discharge hole, and as a result, the distance between the object and the first surface of the plate-like member is The concentration of inert gas at each location within the space may be non-uniform. Even in such a case, by adjusting the amount of inert gas discharged from each gas discharge hole using the discharge amount adjusting section, the non-uniformity of the concentration of the inert gas can be alleviated and eliminated. Furthermore, for example, in the space between the object and the first surface of the plate-like member, the concentration of the inert gas at a specific position can be intentionally increased or conversely lowered. It may be desirable to control the temperature at each location to a desired temperature. Even in such a case, the concentration of inert gas at each position in the space can be freely controlled by adjusting the amount of inert gas discharged from each gas discharge hole using the discharge amount adjustment section. .

(2) In the above electrostatic chuck, the gas flow path includes a common gas flow path and a plurality of individual gas flow paths that are branched from the common gas flow path and connected to each of the gas discharge holes, and The amount adjustment section may include a flow path area adjustment mechanism that increases or decreases the flow path area at a predetermined position of the individual gas flow path connected to each of the gas discharge holes. According to this electrostatic chuck, the amount of inert gas discharged from each gas discharge hole can be adjusted by increasing or decreasing the flow path area at a predetermined position of the individual gas flow path connected to each gas discharge hole. Therefore, the amount of inert gas discharged from each gas discharge hole can be adjusted with a relatively simple configuration.

(3) In the electrostatic chuck, the flow path area adjustment mechanism adjusts the flow path of the individual gas flow path by displacing the position of the tip of the flow path area adjustment mechanism facing the individual gas flow path. It is also possible to have a configuration in which the area is increased or decreased. According to this electrostatic chuck, with a relatively simple configuration, it is possible to increase or decrease the flow area of the individual gas passages connected to each gas discharge hole, and thereby, the inert gas can be discharged from each gas discharge hole. Amount adjustment can be achieved.

(4) In the electrostatic chuck, the plate member is made of ceramic, the predetermined position of the individual gas flow path is a position inside the plate member, and the flow path area adjustment At least a portion of the tip of the mechanism is formed of metal, and the electrostatic chuck is further disposed to cover at least a portion of the tip of the flow path area adjustment mechanism, and is made of ceramic. It is good also as a structure provided with the cap member which is made. According to this electrostatic chuck, the existence of the cap member made of ceramics improves the insulation near the individual gas flow paths, and the tip (metal part) of the flow path area adjustment mechanism and the plate-like Generation of particles due to interference with a member (made of ceramics) can be suppressed.

(5) In the above electrostatic chuck, the gas flow path includes a common gas flow path and a plurality of individual gas flow paths that are branched from the common gas flow path and connected to each of the gas discharge holes, and The amount adjustment section may include a pump mechanism that is disposed in the individual gas flow path connected to each of the gas discharge holes and that sends out gas at a variable flow rate. According to this electrostatic chuck, by changing the flow rate of the inert gas in the individual gas passages using the pump mechanism arranged in the individual gas passages connected to each gas discharge hole, the inert gas is discharged from each gas discharge hole. The amount of inert gas discharged from each gas discharge hole can be adjusted with relatively high precision.

(6) In the above electrostatic chuck, the individual gas flow path is formed across the plate member, the joint portion, and the base member, and the electrostatic chuck further includes the individual gas flow path. The structure may include a protective member formed of an elastomer and interposed between the end surface of the joint portion and the end surface of the joint portion. According to the present electrostatic chuck, the presence of the protective member can prevent the end face of the joint from being exposed to plasma or the like and deteriorating due to the formation of the individual gas channels.

(7) The electrostatic chuck further includes a pressure detection section that detects the pressure near each of the gas discharge holes, and the discharge amount adjustment section adjusts the pressure of each of the gases based on the pressure detection result by the pressure detection section. A configuration may be adopted in which the amount of gas discharged from the discharge hole is adjusted. According to the present electrostatic chuck, it is possible to further improve the controllability of the concentration of inert gas at each position in the space between the object and the first surface of the plate-like member, and the temperature of the object can be further improved. Controllability can be further improved.

(8) In the electrostatic chuck, the discharge amount adjusting section adjusts each of the gases so that the gas discharge amount of the gas discharge hole whose pressure detected by the pressure detection section is relatively low is relatively increased. A configuration may be adopted in which the amount of gas discharged from the discharge hole is adjusted. According to this electrostatic chuck, the amount of inert gas discharged from each gas discharge hole can be adjusted so that the pressure near each gas discharge hole approaches uniformity, so that the The uniformity of the concentration of the inert gas at each position in the space between the object and the surface of the object can be improved, and the in-plane uniformity of the temperature of the object can be improved.

Note that the technology disclosed in this specification can be realized in various forms, for example, in the form of an electrostatic chuck, a semiconductor manufacturing device equipped with an electrostatic chuck, a manufacturing method thereof, etc. is possible.

A perspective view schematically showing the external configuration of an electrostatic chuck 100 in the first embodiment An explanatory diagram schematically showing the XZ cross-sectional configuration of the electrostatic chuck 100 in the first embodiment An explanatory diagram schematically showing the XY plane (top surface) configuration of the electrostatic chuck 100 in the first embodiment An explanatory diagram showing a configuration for adjusting the supply amount of inert gas in the electrostatic chuck 100 of the first embodiment An explanatory diagram schematically showing the XZ cross-sectional configuration of the electrostatic chuck 100 in the second embodiment An explanatory diagram schematically showing the XZ cross-sectional configuration of the electrostatic chuck 100 in the third embodiment

A. First embodiment:
A-1. Configuration of electrostatic chuck 100:
FIG. 1 is a perspective view schematically showing the external configuration of an electrostatic chuck 100 in the first embodiment, and FIG. 2 is an explanatory diagram schematically showing the XZ cross-sectional configuration of the electrostatic chuck 100 in the first embodiment. FIG. 3 is an explanatory diagram schematically showing the XY plane (top surface) configuration of the electrostatic chuck 100 in the first embodiment. Each figure shows mutually orthogonal XYZ axes for specifying directions. In this specification, for convenience, the positive direction of the Z-axis is referred to as an upward direction, and the negative direction of the Z-axis is referred to as a downward direction, but the electrostatic chuck 100 is actually installed in an orientation different from such an orientation. may be done.

The electrostatic chuck 100 is a device that attracts and holds an object (for example, a wafer W) by electrostatic attraction, and is used for semiconductor manufacturing equipment, for example, used to fix the wafer W in a vacuum chamber of a semiconductor manufacturing equipment. It is a part. The electrostatic chuck 100 includes a plate member 10 and a base member 20 that are arranged side by side in a predetermined arrangement direction (in the present embodiment, the vertical direction (Z-axis direction)). The plate-like member 10 and the base member 20 are arranged such that the lower surface S2 (see FIG. 2) of the plate-like member 10 and the upper surface S3 of the base member 20 face each other in the arrangement direction with a joint 30, which will be described later, in between. has been done. That is, the base member 20 is arranged such that the upper surface S3 of the base member 20 is located on the lower surface S2 side of the plate member 10. The lower surface S2 of the plate member 10 corresponds to the second surface in the claims, and the upper surface S3 of the base member 20 corresponds to the third surface in the claims.

The plate-like member 10 is a substantially circular plate-like member when viewed in the Z-axis direction, and in this embodiment is made of a material containing ceramics (eg, alumina, aluminum nitride, etc.). Note that in this embodiment, the plate member 10 is formed of a material containing ceramics as a main component. In this specification, the main component means the component with the highest volume content. The plate-like member 10 includes an outer circumferential portion OP, which is a portion in which a notch is formed on the upper side along the outer circumference, and an inner portion IP located inside the outer circumferential portion OP. The thickness of the inner part IP (thickness in the Z-axis direction, the same applies hereinafter) of the plate-shaped member 10 is thicker than the thickness of the outer peripheral part OP by the notch formed in the outer peripheral part OP. . That is, the thickness of the plate-like member 10 changes at the position of the boundary between the outer peripheral part OP and the inner part IP of the plate-like member 10.

The diameter of the inner part IP of the plate member 10 is, for example, about 50 mm to 500 mm (usually about 200 mm to 350 mm), and the diameter of the outer peripheral part OP of the plate member 10 is, for example, about 60 mm to 510 mm (usually about 210 mm to 360 mm). ) (However, the diameter of the outer peripheral part OP is larger than the diameter of the inner part IP). Further, the thickness of the inner part IP of the plate-like member 10 is, for example, about 1 mm to 10 mm, and the thickness of the outer peripheral part OP of the plate-like member 10 is, for example, about 0.5 mm to 9.5 mm (however, the thickness of the outer peripheral part OP is about 0.5 mm to 9.5 mm). The thickness of the OP is thinner than the thickness of the inner part IP).

Among the upper surfaces S1 of the plate member 10, the upper surface (hereinafter also referred to as "adsorption surface") S11 in the inner side IP is a substantially circular surface that is substantially perpendicular to the Z-axis direction. The suction surface S11 corresponds to the first surface in the claims. Note that in this specification, a direction perpendicular to the Z-axis direction is referred to as a "plane direction."

Among the upper surfaces S1 of the plate-shaped member 10, the upper surface S12 at the outer circumferential portion OP (hereinafter also referred to as "outer circumferential upper surface") is a substantially annular surface substantially orthogonal to the Z-axis direction. For example, a jig (not shown) for fixing the electrostatic chuck 100 is engaged with the outer peripheral upper surface S12 of the plate member 10.

As shown in FIG. 2, a chuck electrode 40 made of a conductive material (for example, tungsten, molybdenum, platinum, etc.) is arranged inside the plate member 10. The shape of the chuck electrode 40 when viewed in the Z-axis direction is, for example, approximately circular. When a voltage is applied to the chuck electrode 40 from a chucking power source (not shown), electrostatic attraction is generated, and the wafer W is attracted and fixed to the attraction surface S11 of the plate member 10 by this electrostatic attraction.

Further, inside the plate-like member 10, a heater electrode 50 is arranged, which is constituted by a resistance heating element containing a conductive material (for example, tungsten, molybdenum, platinum, etc.). When a voltage is applied to the heater electrode 50 from a heater power source (not shown), the heater electrode 50 generates heat, which warms the plate member 10, and the wafer W held on the suction surface S11 of the plate member 10 is heated. It can be warmed. Thereby, control of the temperature distribution of the wafer W is realized.

The base member 20 is, for example, a circular planar plate member having the same diameter as the outer peripheral part OP of the plate-like member 10 or larger in diameter than the outer peripheral part OP of the plate-like member 10, and is made of, for example, metal (such as aluminum or aluminum alloy). ) is formed by. The diameter of the base member 20 is, for example, about 220 mm to 550 mm (usually 220 mm to 350 mm), and the thickness of the base member 20 is, for example, about 20 mm to 40 mm.

The base member 20 is joined to the plate-like member 10 by a joint 30 disposed between the lower surface S2 of the plate-like member 10 and the upper surface S3 of the base member 20. The thickness of the joint portion 30 is, for example, about 0.1 mm to 1 mm. In this embodiment, the joint portion 30 contains a resin material (adhesive material) as a main component. Various resin materials such as silicone resin, fluororesin, acrylic resin, and epoxy resin can be used as the resin material included in the joint portion 30, but silicone resin, which is a resin material with high heat resistance and flexibility, may be used. It is preferable to use a fluororesin or a fluororesin. In addition to the resin material, the joint portion 30 may also contain, for example, a ceramic filler.

A refrigerant flow path 21 is formed inside the base member 20 . When a refrigerant (for example, a fluorine-based inert liquid, water, etc.) is flowed into the refrigerant flow path 21, the base member 20 is cooled, and heat transfer between the base member 20 and the plate-shaped member 10 via the joint 30 occurs. The plate-shaped member 10 is cooled by (heat removal), and the wafer W held on the suction surface S11 of the plate-shaped member 10 is cooled. Thereby, control of the temperature distribution of the wafer W is realized. The coolant flow path 21 corresponds to a cooling mechanism in the claims.

Further, the electrostatic chuck 100 includes an O-ring 110 for protecting the outer circumferential surface of the joint portion 30 from plasma and process gas existing around the electrostatic chuck 100. The O-ring 110 is made of, for example, an elastomer (eg, synthetic rubber). As shown in FIG. 2, the O-ring 110 is in contact with the lower surface S2 of the plate-shaped member 10 and the upper surface S3 of the base member 20, and by exhibiting a sealing function at the corresponding contact points, the O-ring 110 seals the joint portion 30. Prevents the outer peripheral surface from deteriorating due to exposure to plasma or process gas.

A-2. Configuration of suction surface S11 of plate member 10:
As shown in FIGS. 2 and 3, a concave portion 79 and a plurality of convex portions 70 are formed on the suction surface S11 of the plate member 10. More specifically, in the suction surface S11 of the plate-like member 10, a portion where the convex portion 70 is not formed is a concave portion 79.

The plurality of convex portions 70 formed on the suction surface S11 of the plate member 10 are wall-shaped convex portions 70 (hereinafter referred to as "seal band 72") that are continuously formed along the outer periphery of the suction surface S11. including. As shown in FIG. 3, the shape of the seal band 72 when viewed in the Z-axis direction is approximately annular with the center P0 of the suction surface S11 of the plate member 10 as the center. The seal band 72 is formed so as to surround a plurality of gas discharge holes 12, which will be described later, when viewed in the Z-axis direction. Further, as shown in FIG. 2, the shape of the cross section of the seal band 72 (the cross section parallel to the Z axis and passing through the center of the suction surface S11) is approximately rectangular. The height of the seal band 72 is, for example, about 10 μm to 20 μm. Further, the width of the seal band 72 (the size in the direction perpendicular to the stretching direction of the seal band 72 as viewed in the Z-axis direction) is, for example, about 0.5 mm to 5.0 mm. The seal band 72 corresponds to a wall-shaped protrusion in the claims.

Further, the plurality of convex portions 70 formed on the suction surface S11 of the plate-like member 10 are a plurality of independent columnar convex portions 70 formed in the area inside the seal band 72 on the suction surface S11 of the plate-like member 10. (hereinafter referred to as "columnar convex portion 73"). As shown in FIG. 3, the shape of each columnar convex portion 73 when viewed in the Z-axis direction is approximately circular. It is preferable that the plurality of columnar convex portions 73 are arranged at substantially equal intervals when viewed in the Z-axis direction. Further, as shown in FIG. 2, the shape of the cross section (cross section parallel to the Z axis) of each columnar convex portion 73 is approximately rectangular. The height of the columnar convex portion 73 is approximately the same as the height of the seal band 72, and is, for example, about 10 μm to 20 μm. Further, the width of the columnar convex portion 73 (the maximum diameter of the columnar convex portion 73 as viewed in the Z-axis direction) is, for example, about 0.5 mm to 1.5 mm.

The wafer W is supported on the top surface of a plurality of convex portions 70 (seal band 72 and columnar convex portions 73) on the suction surface S11 of the plate member 10. That is, as described above, the suction surface S11 of the plate-like member 10 functions as a suction surface for holding the wafer W, but in more detail, the suction surface S11 of the plurality of convex portions 70 of the suction surface S11 holds the wafer W. It is the top surface. When the wafer W is supported on the top surface of the plurality of convex portions 70, there is a gap between the front surface (lower surface) of the wafer W and the suction surface S11 of the plate member 10 (more specifically, the recess 79 of the suction surface S11). Therefore, space exists. As will be described later, an inert gas is supplied to this space.

A-3. Configuration for inert gas supply:
The electrostatic chuck 100 is designed so that the surface (lower surface) of the wafer W and the suction surface of the plate member 10 are connected to each other in order to improve the heat transfer between the plate member 10 and the wafer W and further improve the controllability of the temperature distribution of the wafer W. A configuration is provided for supplying an inert gas (for example, helium gas) to the space existing between S11 (the recess 79 of the suction surface S11).

That is, as shown in FIGS. 2 and 3, a plurality of gas discharge holes 12 (four gas discharge holes 12a to 12d in this embodiment) are formed in the suction surface S11 of the plate member 10. Furthermore, a gas flow path 130 communicating with the plurality of gas discharge holes 12 is formed inside the electrostatic chuck 100 . In addition, in FIG. 3, for convenience of explanation, each part constituting the gas flow path 130 formed inside the electrostatic chuck 100 is shown with a broken line.

The configuration of the gas flow path 130 will be explained in more detail. As shown in FIG. 2, a base member gas flow path 131 is formed in the base member 20 and extends in the vertical direction from the lower surface S4 to the upper surface S3 of the base member 20. Furthermore, a through hole 132 communicating with the base member gas flow path 131 of the base member 20 is formed in the joint portion 30 . Furthermore, a recess 133 communicating with the through hole 132 of the joint portion 30 is formed on the lower surface S2 of the plate member 10. Further, inside the plate member 10, there is a vertical flow path 134 that communicates with the bottom surface of the recess 133 and extends upward, and a vertical flow path 134 starting from near the upper end of the vertical flow path 134 in the plane direction (in this embodiment, the X-axis direction and the Y-axis direction). The four lateral channels 135 extend in the axial direction), and the four lateral channels 135 have a shape that extends in the surface direction so as to connect the outer peripheral side ends of each lateral channel 135 to each other (in this embodiment, the shape is approximately centered on the center P0 of the suction surface S11). An annular) connecting flow path 136, four branch flow paths 137 extending in the plane direction (X-axis direction and Y-axis direction in this embodiment) starting from a predetermined position of the connection flow path 136, and each branch flow path A gas ejection channel 138 is formed that extends upward from the passage 137 to the suction surface S11 and opens at the gas discharge hole 12 of the suction surface S11. Note that among the constituent parts of the gas flow path 130, the constituent parts other than the branch flow path 137 and the gas jet flow path 138 are gas flow paths (hereinafter referred to as " (also referred to as "common gas flow path"). On the other hand, the branch flow path 137 and the gas ejection flow path 138 are individual gas flow paths (hereinafter also referred to as "individual gas flow paths") that branch from the common gas flow path and are connected to each gas discharge hole 12.

Note that in order to suppress the occurrence of electrical discharge or gas discharge between the plate-like member 10 and the base member 20 via the recess 133 of the plate-like member 10, a breathable plug 160 is arranged in the recess 133. has been done. The breathable plug 160 is a substantially cylindrical member made of an insulating material, and is a porous member having a higher porosity than the plate-like member 10. As a material for forming the breathable plug 160, for example, a porous ceramic body, glass fiber, a heat-resistant polytetrafluoroethylene resin sponge, or the like can be used.

When an inert gas (for example, helium gas) supplied from a gas source (not shown) flows into the base member gas flow path 131, the inert gas flows through the through hole 132 of the joint portion 30 and the plate member 10. It passes through the inside of the breathable plug 160 disposed in the recess 133 and flows into the vertical flow path 134 formed inside the plate member 10 . Thereafter, the inert gas flows from the vertical flow path 134 into the horizontal flow path 135, and flows into each branch flow path 137 while flowing in the planar direction via the horizontal flow path 135 and the connecting flow path 136. Thereafter, the inert gas flows from each branch flow path 137 into the gas ejection flow path 138, and is discharged from each gas discharge hole 12 formed in the suction surface S11. In this way, inert gas is supplied to the space existing between the surface of the wafer W and the suction surface S11 of the plate member 10 (the recess 79 of the suction surface S11).

Here, as described above, the wafer W is supported on the top surface of the plurality of convex portions 70 (seal band 72 and columnar convex portions 73) on the suction surface S11 of the plate member 10. That is, the top surface of the seal band 72 is in contact with the front surface (lower surface) of the wafer W. Therefore, the space existing between the surface of the wafer W and the suction surface S11 of the plate member 10 becomes a space closed by the seal band 72. Therefore, the inert gas supplied to the space remains within the space (except for the gas that leaks through the small gap between the top surface of the seal band 72 and the surface of the wafer W), and and the plate-like member 10.

A-4. Configuration for adjusting the inert gas supply:
The electrostatic chuck 100 of this embodiment has a configuration for adjusting the amount of inert gas supplied to the space existing between the surface of the wafer W and the suction surface S11 of the plate member 10. . FIG. 4 is an explanatory diagram showing a configuration for adjusting the supply amount of inert gas in the electrostatic chuck 100 of the first embodiment. FIG. 4 shows an enlarged XZ cross-sectional configuration of a portion of the electrostatic chuck 100 (X1 portion in FIG. 2).

As shown in FIGS. 2 and 4, the electrostatic chuck 100 of this embodiment includes a positioner 150. The positioner 150 is a substantially cylindrical member extending in the Z-axis direction. In this embodiment, the positioner 150 is provided corresponding to each gas discharge hole 12 formed in the suction surface S11 of the plate member 10. That is, the electrostatic chuck 100 of this embodiment is provided with four positioners 150 corresponding to the four gas discharge holes 12.

Each positioner 150 is arranged in a positioner hole 140 that extends downward from the vicinity of the connection position between the branch flow path 137 and the gas jet flow path 138 connected to each gas discharge hole 12 to the lower surface S4 of the base member 20. . A female screw 141 is formed on the inner peripheral surface of the lower end of the positioner hole 140, and a substantially cylindrical fixing member 162 with a male screw formed on the outer peripheral surface is screwed on the lower end of the positioner hole 140. are doing. The lower end of the positioner 150 is joined to the upper end of the fixing member 162. Therefore, by rotating the fixing member 162 and adjusting the position of the fixing member 162 in the vertical direction, it is possible to adjust the position of the positioner 150 in the vertical direction (reference position Po described later). Further, the positioner hole 140 is kept airtight by the O-ring 164 interposed between the fixing member 162 and the surface of the positioner hole 140. Note that the positioner hole 140 communicates with the branch flow path 137 provided for each gas discharge hole 12, so it is a part of the individual gas flow path, and the positioner hole 140 is a part of the individual gas flow path, and the positioner hole 140 is connected to the plate member 10, the joint portion 30, and the base member. 20.

As shown in FIG. 4, the tip (upper end) of the positioner 150 faces the individual gas flow path (more specifically, near the connection position between the branch flow path 137 and the gas jet flow path 138). . In this embodiment, a portion of the upper end of the positioner 150 (a portion near the center as viewed in the Z-axis direction) protrudes upward. Moreover, the positioner 150 of this embodiment is configured to be deformable in the vertical direction. For example, the positioner 150 is configured with a piezoelectric actuator as disclosed in Japanese Patent Application Publication No. 2015-115542 and Japanese Patent Application Publication No. 2015-122438. The piezoelectric actuator has a structure in which a plurality of piezoelectric elements (piezoelectric ceramics) such as piezo elements (piezoelectric ceramics) are stacked vertically and surrounded by a metal cover, and the piezoelectric actuator moves vertically depending on the supplied driving voltage. transforms into Control of the deformation of the positioner 150 is achieved, for example, by controlling the supply voltage by a control circuit (not shown).

By deforming the positioner 150 in the vertical direction, the position of the tip of the positioner 150 facing the individual gas flow path is displaced, and as a result, a predetermined position of the individual gas flow path (more specifically, a branch flow path 137 and the gas ejection flow path 138 (near the connection position) increases or decreases. When the flow area of the individual gas flow path increases or decreases, the pressure loss of the individual gas flow path increases or decreases, and the flow rate of the inert gas flowing through the individual gas flow path (i.e., the gas discharge hole 12 connected to the individual gas flow path increases or decreases). The amount of inert gas discharged from the inert gas increases or decreases. For example, as shown in FIG. 4, when the tip of the positioner 150 is displaced from the reference position Po to the upper position Pu, the flow area of the individual gas flow paths (branch flow path 137 and gas jet flow path 138) decreases. , the amount of inert gas discharged from the gas discharge holes 12 connected to the individual gas channels is reduced. On the other hand, when the tip of the positioner 150 is displaced from the reference position Po to the lower position Pl, the flow area of the individual gas flow paths (branch flow path 137 and gas jet flow path 138) increases, and the individual gas flow The amount of inert gas discharged from the gas discharge hole 12 connected to the passage increases. In this way, the positioner 150 increases or decreases the flow area of the individual gas flow path by displacing the position of the tip facing the individual gas flow path, thereby increasing or decreasing the gas discharge hole connected to the individual gas flow path. Adjust the amount of inert gas discharged from 12. The positioner 150 corresponds to a discharge amount adjustment section and a flow path area adjustment mechanism in the claims.

In addition, in the electrostatic chuck 100 of this embodiment, as shown in FIG. 4, at least a portion of the tip portion (the portion covered by the metal cover) of the positioner 150 is covered by a cap member 158 made of ceramics. covered. In this embodiment, the cap member 158 covers the entire top surface of the positioner 150.

Further, as described above, the positioner hole 140 constitutes a part of the individual gas flow path, and is formed across the plate member 10, the joint portion 30, and the base member 20. In the electrostatic chuck 100 of this embodiment, as shown in FIG. 2, an O-ring 120 for protecting the end surface of the joint section 30 is disposed between the positioner hole 140 and the end surface of the joint section 30. . The O-ring 120 is made of, for example, an elastomer (eg, synthetic rubber). Note that the material for forming the O-ring 120 is preferably a material that is elastic and has excellent plasma resistance, heat resistance, and chemical resistance. The O-ring 120 corresponds to a protection member in the claims.

A-5. Effects of the first embodiment:
As described above, the electrostatic chuck 100 of this embodiment includes the plate member 10, the chuck electrode 40, the base member 20, and the joint portion 30. The plate-like member 10 is a member having a suction surface S11 and a lower surface S2 on the opposite side to the suction surface S11. The chuck electrode 40 is arranged inside the plate member 10 and generates electrostatic attraction. The base member 20 is a member that has an upper surface S3, is arranged so that the upper surface S3 is located on the lower surface S2 side of the plate member 10, and has a coolant flow path 21. The joining portion 30 is disposed between the lower surface S2 of the plate-like member 10 and the upper surface S3 of the base member 20, and joins the plate-like member 10 and the base member 20. Further, a plurality of gas discharge holes 12 and a continuous wall-shaped seal band 72 surrounding the plurality of gas discharge holes 12 are formed on the suction surface S11 of the plate member 10. A gas flow path 130 communicating with the plurality of gas discharge holes 12 is formed inside the electrostatic chuck 100 . Further, the electrostatic chuck 100 of the present embodiment further includes a positioner 150 provided for each of the plurality of gas discharge holes 12 and for adjusting the amount of inert gas discharged from each gas discharge hole 12.

As described above, the electrostatic chuck 100 of the present embodiment includes the positioner 150 that adjusts the amount of inert gas discharged from each gas discharge hole 12. The amount of gas discharged can be adjusted. Therefore, it is possible to improve the controllability of the concentration of the inert gas at each position in the space between the wafer W and the suction surface S11 of the plate-like member 10, and in turn, it is possible to improve the controllability of the temperature of the wafer W. can.

For example, due to wear of a portion of the seal band 72 over time, inert gas leaks from the space between the wafer W and the suction surface S11 of the plate member 10, and at various positions within the space. The concentration of inert gas may become non-uniform. In such a case, the positioner 150 is controlled so that the non-uniformity in the concentration of the inert gas is alleviated and eliminated. For example, if the seal band 72 in the Y1 section in FIG. In order to increase the amount of inert gas discharged, the positioner 150 provided for the gas discharge hole 12c is deformed to displace the tip of the positioner 150 downward. Alternatively, or in addition to this, the amount of inert gas discharged from the gas discharge holes 12 (12a, 12b, 12d) other than the gas discharge holes 12 (gas discharge holes 12c) located near the portion is reduced. In order to do so, by deforming each positioner 150 provided for each gas discharge hole 12a, 12b, and 12d, the position of the tip of each positioner 150 is displaced upward. By performing such control, non-uniformity in the concentration of the inert gas at each position in the space between the wafer W and the suction surface S11 of the plate-like member 10 is alleviated and eliminated, and the non-uniformity caused by the non-uniformity Deterioration in the controllability of the temperature distribution of the wafer W (for example, deterioration in the in-plane uniformity of the temperature distribution of the wafer W) can be suppressed.

Incidentally, the fact that the concentration of the inert gas is uneven at each position in the space between the wafer W and the suction surface S11 of the plate-like member 10 can be detected based on the quality of each process performed on the wafer W, for example. can do.

Further, for example, due to product variations in the electrostatic chuck 100 (for example, variations in the shape and position of the branch channels 137 and the gas jet channels 138), the amount of inert gas discharged from each gas discharge hole 12 may vary. As a result, the concentration of the inert gas at each position in the space between the wafer W and the suction surface S11 of the plate member 10 may become non-uniform. In such a case, the positioner 150 is controlled so that the non-uniformity in the concentration of the inert gas is alleviated and eliminated. For example, for a gas discharge hole 12 that discharges a smaller amount of inert gas than other gas discharge holes 12, in order to increase the amount of inert gas discharged from the gas discharge hole 12, By deforming the provided positioner 150, the position of the tip of the positioner 150 is displaced downward. Alternatively, or in addition to this, in order to reduce the amount of inert gas discharged from gas discharge holes 12 other than the gas discharge hole 12 (gas discharge holes 12 that discharge a relatively large amount of inert gas), By deforming each positioner 150 provided for the gas discharge hole 12, the position of the tip of each positioner 150 is displaced upward. By performing such control, non-uniformity in the concentration of the inert gas at each position in the space between the wafer W and the suction surface S11 of the plate-like member 10 is alleviated and eliminated, and the non-uniformity caused by the non-uniformity Deterioration in the controllability of the temperature distribution of the wafer W (for example, deterioration in the in-plane uniformity of the temperature distribution of the wafer W) can be suppressed.

Further, for example, in the space between the wafer W and the suction surface S11 of the plate-shaped member 10, the concentration of the inert gas at a specific position may be intentionally increased or conversely lowered. It may be desirable to control the temperature at each location to a desired temperature. In such a case, for example, in order to increase the amount of inert gas discharged from the gas discharge hole 12 near the position where the concentration of inert gas in the space is desired to be increased, the gas By deforming the positioner 150 provided for the discharge hole 12, the position of the tip of the positioner 150 is displaced downward. On the other hand, for example, in order to reduce the amount of inert gas discharged from the gas discharge hole 12 near the position where the concentration of inert gas in the space is desired to be lowered, By deforming the provided positioners 150, the position of the tip of each positioner 150 is displaced upward. By performing such control, the concentration of the inert gas at each position in the space between the wafer W and the suction surface S11 of the plate member 10 can be freely controlled, and the temperature distribution of the wafer W can be controlled. Controllability can be improved.

In addition, in the electrostatic chuck 100 of the present embodiment, the gas flow path 130 is a common gas flow path provided in common for the plurality of gas discharge holes 12 (base member gas flow path 131 of the base member 20, joint portion 30 through-holes 132, recesses 133 in the plate-like member 10, vertical passages 134, horizontal passages 135, connection passages 136), and individual gas passages (branched from the common gas passage and connected to each gas discharge hole 12). It includes a branch flow path 137, a gas jet flow path 138, and a positioner hole 140). Then, the positioner 150 increases or decreases the flow path area at a predetermined position of the individual gas flow path (near the connection position between the branch flow path 137 and the gas jet flow path 138), thereby discharging the gas connected to the individual gas flow path. The amount of inert gas discharged from the hole 12 is adjusted. As described above, according to the electrostatic chuck 100 of the present embodiment, by increasing or decreasing the flow path area at a predetermined position of the individual gas flow path connected to each gas discharge hole 12, inert gas from each gas discharge hole 12 can be reduced. Since the amount of gas discharged can be adjusted, the amount of inert gas discharged from each gas discharge hole 12 can be adjusted with a relatively simple configuration. In the electrostatic chuck 100 of this embodiment, the positioner 150 increases or decreases the flow area of the individual gas flow path by displacing the position of the tip facing the individual gas flow path, so it is relatively simple. With this configuration, it is possible to increase or decrease the flow area of the individual gas flow path connected to each gas discharge hole 12, and thereby it is possible to realize adjustment of the amount of inert gas discharged from each gas discharge hole 12. .

Furthermore, in the electrostatic chuck 100 of this embodiment, the plate member 10 is made of ceramics. Further, the predetermined position at which the positioner 150 increases or decreases the passage area in the individual gas passages is near the connection position between the branch passage 137 and the gas jet passage 138, and this is a position inside the plate member 10. be. Furthermore, at least a portion of the tip of the positioner 150 is formed of metal. Furthermore, the electrostatic chuck 100 of the present embodiment further includes a cap member 158 made of ceramic and arranged to cover at least a portion of the tip of the positioner 150. Therefore, according to the electrostatic chuck 100 of this embodiment, the presence of the cap member 158 made of ceramics can improve the insulation near the individual gas flow paths, and the tip of the positioner 150 that can be deformed in the vertical direction Generation of particles due to interference between the part (metallic part) and the plate member 10 (made of ceramics) can be suppressed.

Furthermore, in the electrostatic chuck 100 of this embodiment, the positioner hole 140 that constitutes a part of the individual gas flow path is formed across the plate member 10, the joint portion 30, and the base member 20. Moreover, the electrostatic chuck 100 of this embodiment further includes an O-ring 120 interposed between the positioner hole 140 and the end surface of the joint portion 30 and formed of an elastomer. Therefore, according to the electrostatic chuck 100 of the present embodiment, the presence of the O-ring 120 prevents the end surface of the joint portion 30 from being exposed to plasma or the like and deteriorating due to the formation of the positioner hole 140. can do.

B. Second embodiment:
FIG. 5 is an explanatory diagram schematically showing the XZ cross-sectional configuration of the electrostatic chuck 100 in the second embodiment. In the following, among the configurations of the electrostatic chuck 100 of the second embodiment, the same components as those of the electrostatic chuck 100 of the first embodiment described above will be given the same reference numerals, and the description thereof will be omitted as appropriate. .

As shown in FIG. 5, the electrostatic chuck 100 of the second embodiment differs from the electrostatic chuck 100 of the first embodiment in that it includes a configuration for detecting the pressure near each gas discharge hole 12. More specifically, in the electrostatic chuck 100 of the second embodiment, pressure detection holes 142 are formed that branch from each gas ejection flow path 138 and extend to the lower surface S4 of the base member 20. 142 is connected to a pressure gauge 143. The pressure gauge 143 is a highly accurate pressure sensor capable of detecting a pressure of, for example, several torr. The pressure gauge 143 detects the pressure in the vicinity of the gas discharge hole 12 by detecting the pressure in the gas jet flow path 138 connected through the pressure detection hole 142 . The pressure gauge 143 corresponds to a pressure detection section in the claims.

The pressure detection result by the pressure gauge 143 is input to the control circuit 148. Control circuit 148 controls positioner 150 based on the pressure value input from pressure gauge 143. For example, when the pressure value detected for a certain gas jet flow path 138 is lower than a specified value, the control circuit 148 increases the amount of inert gas discharged from the gas discharge hole 12 connected to the gas jet flow path 138. In order to do this, the positioner 150 provided for the gas discharge hole 12 is deformed to displace the tip of the positioner 150 downward. On the other hand, if the pressure value detected for a certain gas jet channel 138 is higher than the specified value, the control circuit 148 controls the amount of inert gas discharged from the gas discharge hole 12 connected to the gas jet channel 138. In order to reduce the amount of gas, the positioner 150 provided for the gas discharge hole 12 is deformed to displace the tip of the positioner 150 upward. By performing such control, non-uniformity in the concentration of the inert gas at each position in the space between the wafer W and the suction surface S11 of the plate-like member 10 is alleviated and eliminated, and the non-uniformity caused by the non-uniformity Deterioration in the controllability of the temperature distribution of the wafer W (for example, deterioration in the in-plane uniformity of the temperature distribution of the wafer W) can be suppressed.

In addition, in the second embodiment as well, as illustrated in the first embodiment, in the space between the wafer W and the suction surface S11 of the plate member 10, the concentration of the inert gas at a specific position is intentionally increased. The temperature at each position of the wafer W can also be controlled to a desired temperature by lowering or lowering the temperature.

As described above, the electrostatic chuck 100 of the second embodiment includes the pressure gauge 143 that detects the pressure near each gas discharge hole 12. Further, each positioner 150 adjusts the amount of inert gas discharged from each gas discharge hole 12 based on the pressure detection result by the pressure gauge 143. Therefore, according to the electrostatic chuck 100 of the second embodiment, it is possible to further improve the controllability of the inert gas concentration at each position in the space between the wafer W and the suction surface S11 of the plate member 10. Therefore, the temperature controllability of the wafer W can be further improved. For example, the positioner 150 controls the inert gas discharge from each gas discharge hole 12 so that the amount of inert gas discharged from the gas discharge hole 12 whose pressure detected by the pressure gauge 143 is relatively low increases relatively. Adjust the discharge amount. In this way, the amount of inert gas discharged from each gas discharge hole 12 can be adjusted so that the pressure near each gas discharge hole 12 approaches uniformity, so that the wafer W and the plate-shaped member 10 It is possible to improve the uniformity of the concentration of the inert gas at each position in the space between the suction surface S11 and the in-plane temperature uniformity of the wafer W.

C. Third embodiment:
FIG. 6 is an explanatory diagram schematically showing the XZ cross-sectional configuration of the electrostatic chuck 100 in the third embodiment. In the following, among the configurations of the electrostatic chuck 100 of the third embodiment, the same configurations as those of the electrostatic chuck 100 of the first embodiment or the second embodiment described above are designated by the same reference numerals. Descriptions will be omitted as appropriate.

As shown in FIG. 6, the electrostatic chuck 100 of the third embodiment has a configuration for adjusting the amount of inert gas discharged from each gas discharge hole 12, but the electrostatic chuck 100 of the third embodiment has a structure for adjusting the amount of inert gas discharged from each gas discharge hole 12. This is different from the electric chuck 100. More specifically, the electrostatic chuck 100 of the third embodiment includes a pump 170 instead of the positioner 150. In this embodiment, the pump 170 is provided corresponding to each gas discharge hole 12 formed in the suction surface S11 of the plate-shaped member 10. That is, the electrostatic chuck 100 of this embodiment is provided with four pumps 170 corresponding to the four gas discharge holes 12. The pump 170 corresponds to a discharge amount adjusting section and a pump mechanism in the claims.

Each pump 170 is arranged within a pump hole 146 provided between each branch flow path 137 and each gas jet flow path 138. The connection point between the branch flow path 137 and the pump hole 146 allows gas to flow from the branch flow path 137 to the pump hole 146, and also allows gas to flow from the pump hole 146 to the branch flow path 137. A valve 176 is disposed that does not allow. Similarly, the connection point between the pump hole 146 and the gas jet flow path 138 allows gas to flow from the pump hole 146 to the gas jet flow path 138, and also allows gas to flow from the gas jet flow path 138 to the pump hole. A valve 176 is located that does not allow gas to enter 146. A substantially cylindrical fixing member 163 is fixed to the lower end of the pump hole 146. A lower end of the pump 170 is joined to an upper end of the fixing member 163. Further, the pump hole 146 is kept airtight by the O-ring 164 interposed between the fixing member 163 and the surface of the pump hole 146. Note that the pump holes 146 communicate with the branch channels 137 provided for each gas discharge hole 12, so they are part of the individual gas channels, and the pump holes 146 are connected to the plate member 10, the joint 30, and the base member. 20.

When the pump 170 is placed in the pump hole 146, a space 178 exists above the tip (upper end) of the pump 170. Moreover, the pump 170 of this embodiment is configured to be able to pulsate in the vertical direction. For example, the pump 170 is configured with a piezoelectric actuator as disclosed in Japanese Patent Application Publication No. 2015-115542 and Japanese Patent Application Publication No. 2015-122438. The piezoelectric actuator has a structure in which a plurality of piezoelectric elements (piezoelectric ceramics) such as piezo elements (piezoelectric ceramics) are stacked vertically and surrounded by a metal cover, and the piezoelectric actuator moves vertically depending on the supplied driving voltage. It pulsates. Similarly to the control of the positioner 150 in the second embodiment, control of the pulsation of the pump 170 is performed by a control circuit 148 to which the pressure detection result by the pressure gauge 143 is input, based on the input pressure value. This is achieved by controlling the supply voltage.

By pulsating, the pump 170 sucks inert gas from the branch flow path 137 into the space 178 in the pump hole 146, and further sends out the inert gas from the space 178 to the gas jet flow path 138. As a result, inert gas is discharged from the gas discharge hole 12 connected to the gas jet flow path 138.

The control circuit 148 is configured to increase the amount of inert gas discharged from the gas discharge hole 12 connected to the gas jet flow path 138 when the pressure value detected for a certain gas jet flow path 138 is lower than a specified value. , the amount of inert gas delivered by the pump 170 provided for the gas discharge hole 12 is increased. On the other hand, if the pressure value detected for a certain gas jet channel 138 is higher than the specified value, the control circuit 148 controls the amount of inert gas discharged from the gas discharge hole 12 connected to the gas jet channel 138. In order to reduce this, the amount of inert gas delivered by the pump 170 provided for the gas discharge hole 12 is reduced. By performing such control, non-uniformity in the concentration of the inert gas at each position in the space between the wafer W and the suction surface S11 of the plate-like member 10 is alleviated and eliminated, and the non-uniformity caused by the non-uniformity Deterioration in the controllability of the temperature distribution of the wafer W (for example, deterioration in the in-plane uniformity of the temperature distribution of the wafer W) can be suppressed.

In addition, in the third embodiment, as exemplified in the first embodiment, in the space between the wafer W and the suction surface S11 of the plate member 10, the concentration of the inert gas at a specific position is intentionally increased. The temperature at each position of the wafer W can also be controlled to a desired temperature by lowering or lowering the temperature.

As described above, the electrostatic chuck 100 of the third embodiment includes the pump 170 that is disposed in the individual gas flow path connected to each gas discharge hole 12 and delivers gas at a variable flow rate. Therefore, according to the electrostatic chuck 100 of the second embodiment, by changing the flow rate of the inert gas in each individual gas flow path using the pump 170 disposed in the individual gas flow path connected to each gas discharge hole 12, each The amount of inert gas discharged from the gas discharge holes 12 can be adjusted, and the amount of inert gas discharged from each gas discharge hole 12 can be adjusted with relatively high precision.

D. Variant:
The technology disclosed in this specification is not limited to the above-described embodiments, and can be modified into various forms without departing from the gist thereof. For example, the following modifications are also possible.

The configuration of the electrostatic chuck 100 in the above embodiment is merely an example, and can be modified in various ways. For example, in the embodiment described above, the positioner 150 and the pump 170 are used as a configuration for adjusting the amount of inert gas discharged from each gas discharge hole 12, but the amount of inert gas discharged from each gas discharge hole 12 is Other configurations for adjusting may be used. Further, in the embodiment described above, a configuration for adjusting the amount of inert gas discharged from the gas discharge holes 12 is provided for all gas discharge holes 12, but it is not necessarily provided for all gas discharge holes 12. There's no need. That is, if a configuration for adjusting the amount of inert gas discharged from the gas discharge holes 12 is provided for at least two gas discharge holes 12, the inert gas from at least two gas discharge holes 12 provided with the configuration is provided. The discharge amount of the gas can be adjusted, and the controllability of the inert gas concentration at each position in the space between the wafer W and the suction surface S11 of the plate-shaped member 10 can be improved. temperature controllability can be improved.

Note that the structure that adjusts the amount of inert gas discharged from each gas discharge hole 12 (the part of the structure that actually adjusts the amount of inert gas discharged (for example, the upper end of the positioner 150 or the pump 170) ) is preferably provided within the plate member 10. In this way, a portion responsible for adjusting the amount of inert gas discharged can be disposed near the gas discharge hole 12, and the amount of inert gas discharged can be adjusted more quickly.

Further, in the above embodiment, the positioner 150 and the pump 170 are configured by piezoelectric actuators, but the positioner 150 and the pump 170 can adjust the amount of inert gas discharged from each gas discharge hole 12. Other configurations are also possible.

Further, in the above embodiment, the pressure detection hole 142 provided to detect the pressure near each gas discharge hole 12 communicates with each gas ejection flow path 138, but the pressure detection hole 142 It may be opened directly near the gas discharge hole 12 on the suction surface S11 of the plate member 10 without communicating with the gas jet flow path 138. Even in this case, the pressure near each gas discharge hole 12 can be detected by the pressure gauge 143 via the pressure detection hole 142.

Further, in the above embodiment, the electrostatic chuck 100 includes the heater electrode 50, but the electrostatic chuck 100 does not need to include the heater electrode 50. Even if the electrostatic chuck 100 does not include the heater electrode 50, the temperature distribution of the wafer W can be controlled by supplying the coolant to the coolant flow path 21 formed in the base member 20. Even in such a configuration, by adjusting the amount of inert gas discharged from each gas discharge hole 12 using the positioner 150 and the pump 170, the space between the wafer W and the suction surface S11 of the plate member 10 can be reduced. The temperature controllability of the wafer W can be improved by improving the controllability of the concentration of the inert gas at each position within the wafer W.

Further, in the above embodiment, a monopolar method is adopted in which one chuck electrode 40 is provided inside the plate-like member 10, but a bipolar method is adopted in which a pair of chuck electrodes 40 are provided inside the plate-like member 10. method may be adopted. Further, the materials forming each member in the electrostatic chuck 100 of the above embodiment are merely examples, and each member may be formed of other materials. For example, in the above embodiment, the plate-like member 10 is made of a material containing ceramics, but the plate-like member 10 may be made of other materials.

10: Plate member 12: Gas discharge hole 20: Base member 21: Refrigerant channel 30: Joint portion 40: Chuck electrode 50: Heater electrode 70: Convex portion 72: Seal band 73: Columnar convex portion 79: Concave portion 100: Static Electric chuck 110: O-ring 120: O-ring 130: Gas channel 131: Base member gas channel 132: Through hole 133: Recess 134: Vertical channel 135: Horizontal channel 136: Connection channel 137: Branch channel 138: Gas ejection channel 140: Positioner hole 141: Female thread 142: Pressure detection hole 143: Pressure gauge 146: Pump hole 148: Control circuit 150: Positioner 158: Cap member 160: Ventilation plug 162: Fixing member 163: Fixing member 164: O-ring 170: Pump 176: Valve 178: Space IP: Inside part OP: Outer part S11: Adsorption surface S12: Outer periphery top surface S1: Top surface S2: Bottom surface S3: Top surface S4: Bottom surface W: Wafer

Claims (5)

a plate-like member having a first surface and a second surface opposite to the first surface;
a chuck electrode that is disposed inside the plate member and generates electrostatic attraction;
a base member having a third surface, arranged such that the third surface is located on the second surface side of the plate-like member, and having a cooling mechanism;
a joint portion disposed between the second surface of the plate-like member and the third surface of the base member to join the plate-like member and the base member;
Equipped with
An electrostatic chuck that holds an object on the first surface of the plate-like member,
A plurality of gas discharge holes and a continuous wall-shaped convex portion surrounding the plurality of gas discharge holes are formed on the first surface of the plate-like member,
A gas flow path communicating with the plurality of gas discharge holes is formed inside the electrostatic chuck,
The electrostatic chuck further includes a discharge amount adjusting unit provided for at least two of the plurality of gas discharge holes and adjusting the amount of gas discharged from each of the gas discharge holes ,
The gas flow path is
a common gas flow path;
a plurality of individual gas flow paths branching from the common gas flow path and connected to each of the gas discharge holes;
including;
The discharge amount adjustment section includes a flow path area adjustment mechanism that increases or decreases the flow path area at a predetermined position of the individual gas flow path connected to each of the gas discharge holes,
The passage area adjustment mechanism increases or decreases the passage area of the individual gas passage by displacing the position of the tip of the passage area adjustment mechanism facing the individual gas passage,
The plate-like member is made of ceramics,
The predetermined position of the individual gas flow path is a position inside the plate-like member,
At least a part of the tip of the flow path area adjustment mechanism is formed of metal,
The electrostatic chuck further includes a cap member formed of ceramics and arranged to cover at least a portion of the tip of the flow path area adjustment mechanism.
An electrostatic chuck characterized by: The electrostatic chuck according to claim 1 ,
The individual gas flow path is formed across the plate member, the joint portion, and the base member,
The electrostatic chuck further includes a protective member formed of an elastomer and interposed between the individual gas flow path and the end surface of the joint portion.
An electrostatic chuck characterized by: a plate-like member having a first surface and a second surface opposite to the first surface;
a chuck electrode that is disposed inside the plate member and generates electrostatic attraction;
a base member having a third surface, arranged such that the third surface is located on the second surface side of the plate-like member, and having a cooling mechanism;
a joint portion disposed between the second surface of the plate-like member and the third surface of the base member to join the plate-like member and the base member;
Equipped with
An electrostatic chuck that holds an object on the first surface of the plate-like member,
A plurality of gas discharge holes and a continuous wall-shaped convex portion surrounding the plurality of gas discharge holes are formed on the first surface of the plate-like member,
A gas flow path communicating with the plurality of gas discharge holes is formed inside the electrostatic chuck,
The electrostatic chuck further includes a discharge amount adjusting unit provided for at least two of the plurality of gas discharge holes and adjusting the amount of gas discharged from each of the gas discharge holes,
The gas flow path is
a common gas flow path;
a plurality of individual gas flow paths branching from the common gas flow path and connected to each of the gas discharge holes;
including;
The discharge amount adjustment unit includes a pump mechanism that is disposed in the individual gas flow path connected to each of the gas discharge holes and that delivers gas at a variable flow rate.
An electrostatic chuck characterized by: The electrostatic chuck according to any one of claims 1 to 3 ,
Furthermore, it includes a pressure detection unit that detects the pressure near each of the gas discharge holes,
The discharge amount adjustment section adjusts the amount of gas discharged from each of the gas discharge holes based on the pressure detection result by the pressure detection section.
An electrostatic chuck characterized by: The electrostatic chuck according to claim 4 ,
The discharge amount adjustment section adjusts the amount of gas discharged from each gas discharge hole so that the gas discharge amount of the gas discharge hole whose pressure detected by the pressure detection section is relatively low increases relatively. do,
An electrostatic chuck characterized by:

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