WO2024214659A1 - Electrostatic chuck device - Google Patents

Abstract

An electrostatic chuck device, comprising: a plate-form electrostatic chuck part that has a placement surface on which a plate-form sample is placed, and that has an electrostatic attraction electrode provided to the interior thereof; and a base part that is formed in a disc shape centered on a center axis line and that, on a support surface thereof, supports the electrostatic chuck part from the side opposite from the placement surface. Inside the base part, a refrigerant flow path is provided extending along the support surface. The refrigerant flow path has a first flow path part that is centered on at least one through-hole penetrating the base part in the axial direction of the center axis line and that is formed at an interval from the hole on the radially outer side of the hole, and second flow path parts that are respectively positioned at the two sides of the first flow path part in the extension direction of the refrigerant flow path. The flow path cross-sectional area of the first flow path part is less than the flow path cross-sectional area of the second flow path part.

Description

Electrostatic Chuck Device

The present invention relates to an electrostatic chuck device.
This application claims priority based on Japanese Patent Application No. 2023-066281, filed on April 14, 2023, the contents of which are incorporated herein by reference.

In semiconductor manufacturing equipment that uses plasma, such as plasma etching equipment and plasma CVD equipment, an electrostatic chuck device is used to easily attach and secure a wafer to a mounting surface and to maintain the wafer at a desired temperature. Patent Document 1 discloses a configuration that includes a plate-shaped ceramic body that includes a mounting surface, and a base member that has a cooling passage inside for flowing a cooling medium.

JP 2007-035878 A

In recent years, there has been a trend towards higher integration of semiconductor devices. This has resulted in the need for fine wiring processing technology and three-dimensional packaging technology when manufacturing these devices. When implementing these processing technologies, semiconductor manufacturing equipment is required to reduce the temperature distribution (temperature difference) within the wafer surface. With conventional technology, it has sometimes been impossible to reduce the temperature distribution within the wafer surface to the desired temperature difference, and improvements were required.

The present invention was made in consideration of the above circumstances, and aims to provide an electrostatic chuck device with high thermal uniformity.

The present invention provides an electrostatic chuck device comprising: a plate-shaped electrostatic chuck portion having a mounting surface on which a plate-shaped sample is placed and an electrode for electrostatic attraction provided therein; and a base portion that is disk-shaped about a central axis and supports the electrostatic chuck portion on a support surface from an opposite side to the mounting surface, wherein the base portion has a through hole penetrating the base portion in an axial direction of the central axis, and a coolant flow path provided inside the base portion and extending along the support surface, the coolant flow path having a first flow path portion formed at an interval outward in a hole diameter direction centered on the through hole, and second flow path portions located on both sides of the first flow path portion in an extension direction of the coolant flow path, and a flow path cross-sectional area of the first flow path portion is smaller than a flow path cross-sectional area of the second flow path portion.
That is, the present invention includes the following inventions [1] to [8].
It is also preferable to combine two or more of the following inventions as necessary.
an electrostatic chuck device comprising: a plate-shaped electrostatic chuck portion having a mounting surface on which a plate-shaped sample is placed and having an electrode for electrostatic attraction provided therein; and a base portion which is disk-shaped about a central axis and supports the electrostatic chuck portion on a support surface opposite to the mounting surface, the base portion having at least one through hole penetrating the base portion in an axial direction of the central axis, and a coolant flow path provided inside the base portion and extending along the support surface, the coolant flow path having a first flow path portion and a second flow path portion coupled to both ends of the first flow path portion, the first flow path portion being formed on an outer side of the through hole in a hole diameter direction with a gap therebetween, the second flow path portions being located on both sides of the first flow path portion in an extension direction of the coolant flow path, and a flow path cross-sectional area of the first flow path portion being smaller than a flow path cross-sectional area of the second flow path portion.
[2] The electrostatic chuck device according to [1], wherein the first flow path portion has a smaller width dimension in a direction intersecting the axial direction and the extension direction than the second flow path portion.
[3] The electrostatic chuck device according to [1] or [2], wherein a flow passage cross-sectional area of the first flow passage portion is 0.5 times or more and less than 1.0 times a flow passage cross-sectional area of the second flow passage portion.
[4] The electrostatic chuck device according to any one of [1] to [3], wherein the first flow path portion has a first inner side surface and a second inner side surface facing each other, the first inner side surface being formed on the outer side of the through hole in the hole diameter direction at a distance from the through hole and facing outward in the hole diameter direction, the second inner side surface being formed on the outer side of the first inner side surface in the hole diameter direction at a distance from the first inner side surface and facing inward in the hole diameter direction, and the first inner side surface is formed in an arc shape concentric with an inner peripheral surface of the through hole.
[5] The electrostatic chuck device according to [4], wherein the second inner surface is formed into an arc shape concentric with an inner circumferential surface of the through hole.
[6] The electrostatic chuck device according to [5], wherein the first inner surface and the second inner surface are formed in a range of 20 to 300° about the through hole when viewed in the axial direction.
[7] The electrostatic chuck device described in any one of [4] to [6], wherein in the second flow path portion located on at least one side of the first flow path portion in the extension direction of the coolant flow path, a connection surface that is curved in an arc shape when viewed in the axial direction is formed between an inner surface of the second flow path portion connected to the first inner surface and the first inner surface.
[8] The electrostatic chuck device according to any one of [4] to [7], wherein a thickness of a wall portion formed between an inner peripheral surface of the through hole and the first inner side surface is 1 mm or more and 10 mm or less.
[9] An electrostatic chuck device according to any one of [1] to [8], wherein the coolant flow path has a continuous spiral shape in a plan view, the base portion further has a wall portion that partitions the coolant flow path, the through hole is circular in a plan view and penetrates at least a portion of the wall portion in the axial direction, the wall portion has a first portion having the through hole and a second portion on both sides of the first portion and not having a through hole, a width of the first portion is greater than a width of the second portion in a plan view, the width of the first portion gradually changes, a side surface of the first portion forms an inner surface of the first flow path, and a side surface of the second portion forms an inner surface of the second flow path.

The present invention provides an electrostatic chuck device with high thermal uniformity.

1 is a schematic cross-sectional view illustrating an example of an electrostatic chuck device according to an embodiment. FIG. 2 is a schematic plan view illustrating an example of a refrigerant flow path according to the embodiment. 5A to 5C are schematic diagrams illustrating examples of a first flow path portion and a second flow path portion formed around a through hole in a refrigerant flow path of the embodiment. 4 is a schematic cross-sectional view illustrating an example of a first flow path portion and a second flow path portion formed around a through hole in a refrigerant flow path of the embodiment. FIG. 1A to 1C are diagrams illustrating events that occur around a through hole during processing in a coolant flow path of an embodiment. FIG. 11 is a schematic plan view showing a refrigerant flow path in a modified example of the embodiment.

Below, a preferred example of an electrostatic chuck device according to this embodiment will be described with reference to the drawings. Note that in all of the following drawings, the dimensions and ratios of each component have been appropriately changed to make the drawings easier to understand.

In addition, the present embodiment is specifically described to allow a better understanding of the gist of the invention, and does not limit the present invention unless otherwise specified. For example, unless otherwise limited, conditions such as materials, amounts, types, numbers, sizes, shapes, ratios, and temperatures may be changed, added, or omitted as necessary. Preferred examples may be exchanged or shared between the embodiments described below.
In this specification, the "degree of in-plane temperature distribution (temperature difference) of the electrostatic chuck part (or mounting surface)" may be referred to as "thermal uniformity.""High thermal uniformity" means that the in-plane temperature distribution of the region of the mounting surface of the electrostatic chuck part where a plate-shaped sample is mounted is small.

<Embodiment>
FIG. 1 is a cross-sectional view showing a preferred example of an electrostatic chuck device 1 according to an embodiment.
The electrostatic chuck device 1 has a plate-shaped electrostatic chuck portion 2, a heater element 5, and a disk-shaped base portion 3. The electrostatic chuck device 1 is disk-shaped and centered on a central axis J. The electrostatic chuck portion 2, the heater element 5, and the base portion 3 are layered in this order along the axial direction of the central axis J.

In the following description, the direction of each part of the electrostatic chuck device 1 will be described with respect to the central axis J. In the following description, the axial direction of the central axis J may be simply referred to as the "axial direction", the radial direction centered on the central axis J may be simply referred to as the "radial direction", and the circumferential direction centered on the central axis J may be simply referred to as the "circumferential direction". In addition, in the following description, the up-down direction of each part is defined in a position where the direction in which the central axis J extends coincides with the up-down direction. However, the position of the electrostatic chuck device 1 during use is not limited.

(Electrostatic chuck part)
The electrostatic chuck unit 2 has a mounting plate 11 having an upper surface serving as a mounting surface 11a on which a circular plate-like sample W such as a semiconductor wafer is placed, a support plate 12 which is integrated with the mounting plate 11 and supports the bottom side of the mounting plate 11, an electrostatic attraction electrode 13 provided between the mounting plate 11 and the support plate 12, and an insulating layer 14 which insulates the periphery of the electrostatic attraction electrode 13. That is, the electrostatic chuck unit 2 has the mounting surface 11a on which the plate-like sample W is placed, and the electrostatic attraction electrode 13 is provided inside.

The mounting plate 11 and the support plate 12 are disk-shaped members with the same shape on the overlapping surfaces. The mounting plate 11 and the support plate 12 are made of a ceramic sintered body that has mechanical strength and is durable against corrosive gases and their plasma. The mounting plate 11 and the support plate 12 will be described in detail later.

The support surface 11a of the support plate 11 has multiple protrusions 11b formed at a predetermined interval and each protrusion has a diameter smaller than the thickness of the plate-shaped sample, and these protrusions 11b support the plate-shaped sample W.

Also, a peripheral wall 17 is formed on the periphery of the mounting surface 11a. The peripheral wall 17 is formed at the same height as the protrusion 11b, and supports the plate-shaped sample W together with the protrusion 11b.

The electrostatic adsorption electrode 13 is used as an electrode for an electrostatic chuck to generate an electric charge and fix the plate-shaped sample W by electrostatic adsorption force. The shape and size of the electrostatic adsorption electrode 13 are appropriately adjusted depending on the application.

The electrostatic attraction electrode 13 can be made of any material. For example, it is preferable that the electrode 13 is made of conductive ceramics such as aluminum oxide-tantalum carbide (Al ₂ O ₃ -Ta ₄ C ₅ ) conductive composite sintered body, aluminum oxide-tungsten (Al ₂ O ₃ -W) conductive composite sintered body, aluminum oxide-silicon carbide (Al ₂ O ₃ -SiC) conductive composite sintered body, aluminum nitride-tungsten (AlN-W) conductive composite sintered body, aluminum nitride-tantalum (AlN-Ta) conductive composite sintered body, or yttrium oxide-molybdenum (Y ₂ O ₃ -Mo) conductive composite sintered body, or a high melting point metal such as tungsten (W), tantalum (Ta), or molybdenum (Mo).

The electrostatic attraction electrode 13 can be easily formed by a film formation method such as sputtering or vapor deposition, or a coating method such as screen printing.

The insulating layer 14 surrounds the electrostatic attraction electrode 13 to protect it from corrosive gases and their plasma. The insulating layer 14 also bonds and integrates the boundary between the mounting plate 11 and the support plate 12, i.e., the peripheral area other than the electrostatic attraction electrode 13. The insulating layer 14 is made of an insulating material that has the same composition or the same main component as the material that constitutes the mounting plate 11 and the support plate 12.

(Heater element)
The heater element 5 heats the electrostatic chuck part 2. The heater element 5 is disposed on the lower surface side of the electrostatic chuck part 2. The structure and material of the heater element 5 can be selected arbitrarily. For example, the heater element 5 is obtained by processing a non-magnetic metal thin plate having a constant thickness of 0.2 mm or less, preferably about 0.1 mm, into a desired heater shape, such as a meandering shape of a strip-shaped conductive thin plate, with an overall contour of a circular ring shape. As the non-magnetic metal thin plate, for example, a titanium (Ti) thin plate, a tungsten (W) thin plate, a molybdenum (Mo) thin plate, etc. can be used. To form the heater element 5 into a predetermined heater shape, for example, a photolithography method or laser processing is used.

The heater element 5 may be provided by adhering a non-magnetic metal sheet to the electrostatic chuck portion 2 and then processing and molding it on the surface of the electrostatic chuck portion 2. The heater element 5 may also be separately processed and molded in a position different from the electrostatic chuck portion 2, and then transferred and printed on the surface of the electrostatic chuck portion 2.

The heater element 5 is adhered and fixed to the bottom surface of the support plate 12 by adhesive 4, which is a sheet or film of silicone resin or acrylic resin that has uniform thickness, heat resistance, and insulating properties.

The electrostatic chuck portion 2 and the base portion 3 are bonded via an adhesive layer 8 provided between the electrostatic chuck portion 2 and the base portion 3. The adhesive layer 8 is formed, for example, from a hardened body obtained by heating and hardening a silicone-based resin composition or from an acrylic resin. The adhesive layer 8 is preferably formed, for example, by placing a resin composition having fluidity between the electrostatic chuck portion 2 and the base portion 3 and then heating and hardening it. As a result, the unevenness between the electrostatic chuck portion 2 and the base portion 3 is filled with the adhesive layer 8, making it difficult for gaps or defects to occur in the adhesive layer 8. Therefore, the thermal conductivity characteristics of the adhesive layer 8 can be made uniform within the surface, and the thermal uniformity of the electrostatic chuck portion 2 can be improved.

(Base part)
The base portion 3 cools the electrostatic chuck portion 2. The base portion 3 is disk-shaped and centered on a central axis J. The base portion 3 has a support surface 3a that supports the electrostatic chuck portion 2, and a bottom surface 3b facing the opposite side to the support surface 3a. The electrostatic chuck portion 2 supports the electrostatic chuck portion 2 on the support surface 3a from the opposite side to the mounting surface 11a.

The material constituting the base portion 3 is not particularly limited as long as it is a metal with excellent thermal conductivity, electrical conductivity, and workability, or a composite material containing such a metal, and for example, aluminum (Al), aluminum alloy, copper (Cu), titanium (Ti), copper alloy, stainless steel (SUS), etc. are preferably used. At least the surface of the base portion 3 exposed to the plasma is preferably anodized or has an insulating film such as alumina formed thereon.

A refrigerant flow path 40 through which the refrigerant flows is provided inside the base portion 3. The refrigerant flow path 40 is provided with an inlet 40a that draws the refrigerant into the refrigerant flow path 40 from outside the base portion 3, and an outlet 40b that discharges the refrigerant in the refrigerant flow path 40 to outside the base portion 3. The inlet 40a and the outlet 40b open to the bottom surface 3b of the base portion 3. Note that in FIG. 1, the radial positions of the inlet 40a and the outlet 40b are illustrated in a schematic manner and do not represent their actual positions.

The refrigerant flow path 40 extends along the support surface 3a. That is, the refrigerant flow path 40 extends along a plane perpendicular to the central axis J. The refrigerant flow path 40 has a rectangular flow path cross section over its entire length. In the refrigerant flow path 40 of this embodiment, the axial dimension Dx (depth) of the refrigerant flow path 40 is uniform over the entire length of the refrigerant flow path 40. The refrigerant flow path 40 has an upper member 35 and a lower member 36. That is, the refrigerant flow path 40 may be formed from the upper member 35 and the lower member 36. The upper member 35 is a plate-shaped member whose thickness direction is in the axial direction. The lower member 36 is a plate-shaped member whose axial thickness dimension is greater than that of the upper member 35.

The upper surface of the lower member 36 is provided with grooves 31g that open upward. In the lower member 36, the portions between the grooves 31g form wall portions 50. That is, the base portion 3 has wall portions 50. The wall portions 50 separate the grooves 31g. The lower member 36 also has an outer periphery (outer edge portion) that surrounds the wall portions 50 and the groove portions 31g and is connected to a portion of the wall portions 50. The outer periphery has a constant thickness, and it is preferable that at least a portion of it is annular or approximately annular in plan view.

The opening of groove 31g is covered by upper member 35. The refrigerant flows within the area surrounded by the inner surface of groove 31g in lower member 36 and upper member 35. That is, refrigerant flow path 40 is formed in the area surrounded by the inner surfaces (bottom surface and two opposing side surfaces) of groove 31g and the lower surface of upper member 35. Wall portion 50 also divides refrigerant flow path 40 in the radial direction. The lower surface of upper member 35 and the upper surface of lower member 36 are joined to each other by any selected means, for example, a joining means such as brazing.

FIG. 2 is a schematic diagram of the coolant flow path 40 of the present embodiment as viewed from above.
The refrigerant flow path 40 of this embodiment has a spiral shape in a plan view, more specifically, a spiral shape that spreads radially outward from the central axis J. The refrigerant flow path 40 of this embodiment is continuous over its entire length. In this embodiment, the refrigerant flow path 40 is continuously spaced away from the central axis J while the radius of curvature increases along the circumferential direction. A wall portion 50 is located between flow path portions of the refrigerant flow path 40 that overlap in the radial direction. The wall portion 50 defines the refrigerant flow path 40 in a spiral shape centered on the central axis J.

The refrigerant flow path 40 has an outer peripheral flow path section 41 and an inner peripheral flow path section 42. The outer peripheral flow path section 41 is located in the outermost region of the entire length of the refrigerant flow path 40, and is a region that extends circumferentially for one revolution or less around the central axis J. On the other hand, the inner peripheral flow path section 42 is located radially inward of the outer peripheral flow path section 41 of the entire length of the refrigerant flow path 40. The outer peripheral flow path section 41 and the inner peripheral flow path section 42 are connected to each other. In this embodiment, the inlet 40a is provided in the outer peripheral flow path section 41, and the outlet 40b is provided in the inner peripheral flow path section 42. The inlet 40a and the outlet 40b are provided at or near the end of the refrigerant flow path 40, respectively. Therefore, the refrigerant in this embodiment flows through the refrigerant flow path 40 in the order of the outer peripheral flow path section 41 and the inner peripheral flow path section 42.

The outer peripheral flow passage section 41 is disposed at the outermost periphery of the refrigerant flow passage 40. In this example, the outer peripheral flow passage section 41 extends in an arc shape for approximately 3/4 of the circumference around the central axis J. An inlet 40a is provided at one end of the outer peripheral flow passage section 41. The other end of the outer peripheral flow passage section 41 is connected to the inner peripheral flow passage section 42.

The outer peripheral flow passage portion 41 has a uniform width dimension over its entire length. In the refrigerant flow passage 40 of this embodiment, the flow passage cross section is rectangular over its entire length, and the axial dimension (depth) is uniform. Therefore, the outer peripheral flow passage portion 41 has a uniform flow passage cross-sectional area over its entire length. The flow passage cross section may be considered as a cross section in a direction intersecting the axial direction and the extension direction of the flow passage.

The inner circumferential flow passage portion 42 is a spiral shape that extends approximately one and a half revolutions around the central axis J. One end of the inner circumferential flow passage portion 42 is connected to the outer circumferential flow passage portion 41. The other end of the inner circumferential flow passage portion 42 is provided with an outlet 40b.

The width dimension of the inner circumferential flow passage portion 42 is continuously reduced as it moves radially outward. Therefore, the flow passage cross-sectional area of the inner circumferential flow passage portion 42 is continuously reduced as it moves radially outward.

The wall portion 50 is spiral-shaped and extends around the central axis J by approximately one and three-quarters of a revolution. In this embodiment, the wall portion 50 moves continuously away from the central axis J while increasing its radius of curvature in the circumferential direction. In the inner region 50A of the wall portion 50, the wall portion 50 is positioned between and defines the inner circumferential flow passage portions 42. In the outer region 50B of the wall portion 50, the wall portion 50 is positioned between and defines the outer circumferential flow passage portion 41 and the inner circumferential flow passage portion 42.

The radial dimension of the wall portion 50 becomes continuously smaller as it moves away from the central axis J. Therefore, in the refrigerant flow path 40, the radial distance between the flow path portions that are arranged to overlap in the radial direction becomes continuously smaller as it moves away from the central axis J. The through hole 80 may be disposed at the center of the radial dimension of the wall portion 50. The radial dimension of the wall portion 50 may once widen around the through hole 80.

The electrostatic chuck device 1 has a through hole 80 that penetrates the electrostatic chuck portion 2 and the base portion 3 in the axial direction. The through hole 80 is formed, for example, as a lift pin insertion hole. The number of the through holes 80 can be selected arbitrarily, and a plurality of the through holes 80 may be provided. For example, the number of the through holes 80 may be 1 to 50, 2 to 30, 3 to 10, or 4 to 6. In this embodiment, the through holes 80 are formed at a plurality of locations, for example, three locations spaced apart in the circumferential direction centered on the central axis J. The number and arrangement of the through holes 80 are not limited in any way. A lift pin (not shown) for lifting up the plate-shaped sample W is inserted into the through hole 80 as a lift pin insertion hole. The lift pin rises and falls the plate-shaped sample W by appearing and disappearing from within the through hole 80 above the mounting surface 11a. The shape of the through hole 80 is, for example, circular in a plan view.
The through-hole 80 may be for other purposes, such as a gas supply hole. The through-hole 80 opens to the mounting surface 11a. When used as a gas supply hole, a cooling gas such as He is supplied to the through-hole 80. The cooling gas introduced from the gas supply hole flows through the gap between the mounting surface 11a and the lower surface of the plate-shaped sample W and between the multiple protrusions 11b to cool the plate-shaped sample W.

Each through hole 80 penetrates the base portion 3 in the axial direction. That is, the base portion 3 has a through hole 80 and a refrigerant flow path 40. The through hole 80 penetrates a part of the wall portion 50 of the base portion 3 in the axial direction. It is preferable that the through hole 80 and the refrigerant flow path 40 are not connected to each other. The through hole 80 is formed between the refrigerant flow paths 40 adjacent to each other in the radial direction. That is, each through hole 80 is provided in the wall portion 50 of the base portion 3. The through hole 80 may be located between the inner circumferential flow path portions 42 in the inner peripheral region 50A, and/or may be located between the outer peripheral flow path portion 41 and the inner circumferential flow path portion 42 in the outer peripheral region 50B.
In the following description, when the base portion 3 is viewed in the axial direction, the radial direction of the through hole 80 with the through hole 80 at the center may be referred to as the hole radial direction.

FIG. 3 is a schematic diagram showing a first flow path portion and a second flow path portion formed around a through hole in a refrigerant flow path of an embodiment. In FIG. 3, two combinations of the first flow path portion and the second flow path portion are shown through a wall portion 50. The wall portion 50 has a first portion in which a through hole 80 is provided and a second portion located on both sides of the first portion and in which no through hole is provided. In a plan view, the width of the first portion (the radial dimension including the through hole) is larger than the width of the second portion and gradually changes. The first portion has a convex outer wall. The outer surface of the first portion is the inner surface of the first flow path portion, and the outer surface of the second portion is the inner surface of the second flow path portion.
As shown in FIG. 3, the width of the refrigerant flow path 40 is narrowed around the through hole 80, so that the cross-sectional area of the flow path is narrowed. The refrigerant flow path 40 has a first flow path portion 40N and a second flow path portion 40W connected to both sides thereof. The length of the second flow path portion 40W in the extension direction can be selected arbitrarily, but may be, for example, about 1 to 5 times or 2 to 4 times the length of the first flow path portion 40N. The first flow path portion 40N is in contact with the wall portion 50 at the location where the through hole 80 is provided. That is, the first flow path portion 40N is formed on the outer side of the through hole 80 in the hole diameter direction with a space therebetween, with the through hole 80 as the center. The first flow path portion 40N is curved so as to follow the hole inner circumferential surface 80f of the through hole 80 outside the through hole 80, i.e., on the outer side in the hole diameter direction. The second flow path portion 40W is located on both sides of the first flow path portion 40N in the extension direction of the refrigerant flow path 40. The second flow path portion 40W is continuous with the first flow path portion 40N.

FIG. 4 is a cross-sectional view showing a first flow path portion formed around a through hole and a second flow path portion coupled to the first flow path portion in a refrigerant flow path of the embodiment.
As shown in FIG. 3, the width dimension Wn of the first flow path portion 40N is smaller than the width dimension Ww of the second flow path portion 40W. As shown in FIG. 4, the height (depth) of the first flow path portion 40N is the same as the height (depth) of the second flow path portion 40W. Therefore, the flow path cross-sectional area of the first flow path portion 40N is smaller than the flow path cross-sectional area of the second flow path portion 40W. In this way, since the flow path cross-sectional area of the first flow path portion 40N is smaller than the flow path cross-sectional area of the second flow path portion 40W, the flow velocity of the refrigerant flowing through the refrigerant flow path 40 is higher in the first flow path portion 40N having a smaller flow path cross-sectional area than in the second flow path portion 40W. As a result, heat is efficiently removed from the wall portion 50 around the through hole 80.

Here, the flow path cross-sectional area of the first flow path section 40N is preferably 0.5 times or more and less than 1.0 times the flow path cross-sectional area of the second flow path section 40W. If the flow path cross-sectional area of the first flow path section 40N is less than 0.5 times the flow path cross-sectional area of the second flow path section 40W, the pressure loss in the first flow path section 40N is likely to be excessively high. On the other hand, if the flow path cross-sectional area of the first flow path section 40N is 1 time or more the flow path cross-sectional area of the second flow path section 40W, the flow rate of the refrigerant in the first flow path section 40N becomes smaller than that in the second flow path section 40W. The flow path cross-sectional area of the first flow path section 40N is more preferably 0.6 times or more and less than 0.97 times the flow path cross-sectional area of the second flow path section 40W, and even more preferably 0.7 times or more and less than 0.95 times. It may be 0.75 times or more and less than 0.90 times, or 0.80 times or more and less than 0.85 times.

As shown in FIG. 3, the first flow path portion 40N has a first inner side surface 40s and a second inner side surface 40t facing each other.
The first inner side surface 40s is formed with a gap therebetween on the outer side in the hole diameter direction of the through hole 80, with the through hole 80 as the center. The first inner side surface 40s faces the outer side in the hole diameter direction, that is, in a direction away from the through hole 80. The first inner side surface 40s is formed in an arc shape that is concentric with the hole inner circumferential surface 80f of the through hole 80. As a result, the first inner side surface 40s protrudes outward in the hole diameter direction relative to the inner side surfaces 40g of the second flow path portions 40W located on both sides of the first flow path portion 40N in the extension direction of the refrigerant flow path 40.

The thickness T of the wall portion 50 formed between the first inner surface 40s and the inner peripheral surface 80f of the through hole 80 is selected arbitrarily, but is preferably 1 mm or more and 10 mm or less. It may be 1 mm or more and 3 mm or less, 3 mm or more and 6 mm or less, or 6 mm or more and 10 mm or less. If the thickness T is less than 1 mm, the mechanical strength of the wall portion 50 may be insufficient. Furthermore, if the thickness T exceeds 10 mm, the wall portion 50 becomes too thick, which may lead to a decrease in the cooling effect of the refrigerant flowing through the refrigerant flow path 40.

The second inner surface 40t is formed with a gap between it and the first inner surface 40s on the outer side in the hole diameter direction. The second inner surface 40t faces inward in the hole diameter direction, that is, the opposite direction to the direction away from the through hole 80. The second inner surface 40t is formed in an arc shape that is concentric with the hole inner surface 80f of the through hole 80. In other words, the first inner surface 40s and the second inner surface 40t are each formed concentric with the hole inner surface 80f of the through hole 80, as shown in FIG. 3.

Here, the first inner surface 40s and the second inner surface 40t are formed concentrically with the inner surface 80f of the through hole 80, but the present invention is not limited to these examples. For example, only one of the inner surfaces may be formed concentrically. These may be curved surfaces that are not concentric. For example, the first inner surface 40s and the second inner surface 40t may be curved with an appropriate curvature, rather than being concentric with the inner surface 80f of the through hole 80. In addition, from the viewpoint of making the flow path cross-sectional area of the first flow path section 40N smaller than the flow path cross-sectional area of the second flow path section 40W, only the first inner surface 40s may be made to protrude outward in the hole diameter direction relative to the inner surface 40g of the second flow path section 40W, and the second inner surface 40t may be formed to be smoothly continuous with the inner surface 40h of the second flow path section 40W without protruding.

When the first inner side surface 40s and the second inner side surface 40t are viewed from the axial direction, the angle θ formed by the concentrically formed portion and the center of the through hole 80 can be selected arbitrarily, but is preferably formed in the range of 20 to 300°. It may be in the range of 20 to 45°, 45 to 90°, 90 to 180°, or 180 to 300°. When the angle θ is less than 20°, the first inner side surface 40s will not contribute much to reducing the flow path cross-sectional area of the first flow path portion 40N by protruding outward in the hole diameter direction. When the angle θ exceeds 300°, the wall portion 50 between the hole inner peripheral surface 80f of the through hole 80 and the first inner side surface 40s will have a shape close to a cylinder that continues in the circumferential direction around the through hole 80. This increases the axial rigidity of the wall portion 50 around the through hole 80. Then, as shown by the two-dot chain line L1 in FIG. 5, when cutting the flat surface such as the support surface 3a of the base portion 3 with a machine tool, the portion P1 of the wall portion 50 around the through hole 80 is bent downwardly by the stress applied by the machine tool smaller than the portion P2 around the portion P1 where the refrigerant flow path 40 is formed under the upper member 35. The portion P2 is cut in a state where it is bent downwardly by the stress from the machine tool, so the amount of cutting of the upper member 35 is small. In contrast, the portion P1 of the wall portion 50 around the through hole 80 is bent downwardly by the stress from the machine tool smaller, so the amount of cutting is large accordingly. As a result, when the bending of the portion P2 where the refrigerant flow path 40 is formed is restored after the cutting process is completed, the portion P1 of the wall portion 50 around the through hole 80 is lower than the portion P2 where the refrigerant flow path 40 is formed. As a result, when the plate-shaped sample W is placed on the support surface 3a, a small gap may be generated between the portion P1 of the wall portion 50 around the through hole 80 and the plate-shaped sample W.
In contrast, by setting the angle θ to less than 300°, it is possible to prevent the above-mentioned phenomenon from occurring.

Also, as shown in FIG. 3, in the second flow path section 40W on both sides of the first flow path section 40N in the extension direction of the refrigerant flow path 40, a connection surface 40j that is curved in an arc shape when viewed in the axial direction is formed between the inner surface 40g connected to the first inner surface 40s and the first inner surface 40s. Also, a connection surface 40k that is curved in an arc shape when viewed in the axial direction is formed between the inner surface 40h of the second flow path section 40W that is connected to the second inner surface 40t and the second inner surface 40t.

(Effects of the embodiment)
In the electrostatic chuck device 1 of this embodiment, the coolant flow passage 40 has a first flow passage portion 40N formed at an interval on the outer side of the hole diameter direction of the through hole 80, and a second flow passage portion 40W located on both sides of the first flow passage portion 40N in the extension direction of the coolant flow passage 40. The flow passage cross-sectional area of the first flow passage portion 40N is smaller than that of the second flow passage portion 40W. As a result, the flow rate of the coolant in the coolant flow passage 40 is higher in the first flow passage portion 40N having a smaller flow passage cross-sectional area than in the second flow passage portion 40W having a larger flow passage cross-sectional area. As a result, the cooling performance in the first flow passage portion 40N is improved. A lift pin is inserted into the through hole 80 as necessary, or a cooling gas such as He is filled. An insulating part is preferably inserted into the through hole 80 to electrically insulate them from the base member. However, as a result, the heat insulation performance of the through hole 80 is increased, and the cooling performance is reduced. As a result, the cooling effect of the coolant around the through hole 80 is reduced, and the temperature is easily increased. In response to this, by making the flow passage cross-sectional area of the first flow passage portion 40N smaller than the flow passage cross-sectional area of the second flow passage portion 40W, it is possible to provide an electrostatic chuck device 1 with high thermal uniformity.

The first flow path section 40N of this embodiment has a smaller width dimension in the direction intersecting the axial direction and the extension direction than the second flow path section 40W. In this way, the flow path cross-sectional area of the first flow path section 40N can be easily made smaller than the flow path cross-sectional area of the second flow path section 40W.

In this embodiment, the flow path cross-sectional area of the first flow path section 40N is preferably 0.5 times or more and less than 1.0 times the flow path cross-sectional area of the second flow path section 40W. This makes it possible to efficiently improve thermal uniformity by reducing the flow path step area of the first flow path section 40N.

The first flow passage portion 40N of this embodiment has a first inner surface 40s and a second inner surface 40t, and the first inner surface 40s is preferably formed in an arc shape that is concentric with the hole inner surface 80f of the through hole 80. This makes it possible to make the thickness T of the wall portion 50 between the first inner surface 40s and the hole inner surface 80f constant and improve thermal uniformity.

In this embodiment, the second inner surface 40t is preferably formed in an arc shape that is concentric with the inner peripheral surface 80f of the through hole 80. As a result, the first inner surface 40s and the second inner surface 40t are formed concentrically, and the first flow passage portion 40N can be easily formed by a machine tool.

In this embodiment, the first inner surface 40s and the second inner surface 40t are preferably formed in a range of 20 to 300° from the center of the through hole 80 when viewed in the axial direction. This makes it possible to reduce the flow path step area of the first flow path section 40N while preventing the rigidity of the wall section 50 around the through hole 80 from becoming excessively high.

In this embodiment, a connection surface 40j is formed between the first inner surface 40s and the inner surface 40g connected to the first inner surface 40s. The connection surface 40j is preferably a curved surface in a plan view. This can prevent separation from occurring at the boundary between the first inner surface 40s and the inner surface 40g during the flow of refrigerant in the refrigerant flow path 40. This prevents areas with low cooling efficiency from occurring around the through hole 80, improving thermal uniformity.

In this embodiment, the thickness of the wall portion 50 formed between the inner circumferential surface of the through hole 80 and the first inner surface 40s is preferably 1 mm or more and 10 mm or less. This ensures the strength of the wall portion 50 while preventing a decrease in thermal uniformity.

In addition, the inner circumferential flow passage portion 42 in this embodiment is positioned radially inward from the outer circumferential flow passage portion 41. The base portion 3 actively cools the area of the electrostatic chuck portion 2 that overlaps with the plate-shaped sample W when viewed from the axial direction, thereby keeping the temperature of the plate-shaped sample W constant. According to this embodiment, by providing the inner circumferential flow passage portion 42 and the outer circumferential flow passage portion 41 and optimizing the configuration of each flow passage, it is possible to improve the thermal uniformity of the electrostatic chuck portion 2 up to the vicinity of the outer edge Wa of the plate-shaped sample W.

<Modifications of the embodiment>
In the above embodiment, the refrigerant flow passage 40 has the outer circumferential flow passage portion 41 and the inner circumferential flow passage portion 42, but is not limited to this.
Fig. 6 is a schematic diagram showing a refrigerant flow path 140 according to a modified example of the embodiment. The refrigerant flow path 140 according to the second embodiment will be described below with reference to Fig. 3. Note that the same components as those in the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

(Flow path)
The refrigerant flow path 140 of this embodiment has a double spiral shape that turns back near the central axis J. The double spiral of the refrigerant flow path 140 spreads radially outward with respect to the central axis J. The refrigerant flow path 140 of this embodiment is continuous over its entire length. The refrigerant flow path 140 of this embodiment has a rectangular flow path cross section over its entire length, and its axial dimension is uniform. The wall portion 150 is located between the radially overlapping portions of the refrigerant flow path 140. The wall portion 150 defines the refrigerant flow path 140 in a spiral shape centered on the central axis J.

The refrigerant flow path 140 has an outer circumferential flow path portion 141 with a constant width, and an inner circumferential flow path portion 142 that is disposed radially inward of the outer circumferential flow path portion 141. The outer circumferential flow path portion 141 and the inner circumferential flow path portion 142 are connected to each other. In this embodiment, the inlet 140a is provided in the inner circumferential flow path portion 142, and the outlet 140b is provided in the outer circumferential flow path portion 141. Therefore, the refrigerant in this embodiment flows through the refrigerant flow path 40 in the order of the inner circumferential flow path portion 142 and the outer circumferential flow path portion 141.

The outer peripheral flow passage portion 141 is disposed at the outermost periphery of the refrigerant flow passage 140. The outer peripheral flow passage portion 141 extends in an arc shape, for example, about 6/10 to 9/10 or about 7/10 to 8/10 of a circumference, or in a specific example, about 3/4 of a circumference, around the central axis J. The inner peripheral flow passage portion 142 is connected to one end of the outer peripheral flow passage portion 141. An outlet 140b is provided at the other end of the outer peripheral flow passage portion 141. It is also preferable that the outer peripheral flow passage portion 141 overlaps with the outer edge Wa of the plate-shaped sample W when viewed from the axial direction. As described above, the outer peripheral flow passage portion 141 has a uniform width dimension over its entire length. Therefore, the outer peripheral flow passage portion 141 has a uniform flow passage cross-sectional area over its entire length.

The inner circumferential flow passage portion 142 has, from the inside, a first arc portion 142A, a second arc portion 142B, and a third arc portion 142C, each of which has a constant width. The inner circumferential flow passage portion 142 further has a first connecting portion 143A, a second connecting portion 143B, and a third connecting portion 143C, which connect the arc portions together or connect the outer circumferential flow passage portion 141 and the second arc portion 142B. The first arc portion 142A, the second arc portion 142B, and the third arc portion 142C extend in an arc shape centered on the central axis J. The first arc portion 142A, the second arc portion 142B, and the third arc portion 142C are arranged concentrically centered on the central axis J.

The first arc portion 142A is located at the innermost circumference of the inner circumferential flow path portion 142. The first arc portion 142A extends in an arc shape for approximately 3/4 of the circumference around the central axis J. The first connecting portion 143A is connected to one end of the first arc portion 142A. The second connecting portion 143B is connected to the other end of the first arc portion 142A. The width dimension of the first arc portion 142A is uniform over its entire length. Therefore, the first arc portion 142A has a uniform flow path cross-sectional area over its entire length.

The second arc portion 142B is located radially outside the first arc portion 142A. The second arc portion 142B is located radially between the first arc portion 142A and the third arc portion 142C. The second arc portion 142B extends in an arc shape for approximately 3/4 of a circumference around the central axis J. The first connecting portion 143A is connected to one end of the second arc portion 142B. The third connecting portion 143C is connected to the other end of the second arc portion 142B. The second arc portion 142B has a uniform width dimension over its entire length. Therefore, the second arc portion 142B has a uniform flow passage cross-sectional area over its entire length.

The third arc portion 142C is located radially outside the second arc portion 142B. The third arc portion 142C is located radially between the second arc portion 142B and the outer peripheral flow passage portion 141. The third arc portion 142C extends in an arc shape for approximately 3/4 of a circumference around the central axis J. The second connecting portion 143B is connected to one end of the third arc portion 142C. The inlet 140a is provided at the other end of the third arc portion 142C. The width dimension of the third arc portion 142C is uniform over its entire length. Therefore, the third arc portion 142C has a uniform flow passage cross-sectional area over its entire length.

The width dimension D2 of the second arc portion 142B is smaller than the width dimension D1 of the first arc portion 142A (D2<D1). Furthermore, the width dimension D3 of the third arc portion 142C is smaller than the width dimension D2 of the second arc portion 142B (D3<D2). In other words, among the multiple arc portions 142A, 142B, and 142C, the arc portion located radially outward from the other arc portions has a smaller radial dimension (width) than the other arc portions located on the inner side (D3<D2<D1). Furthermore, the width dimension D4 of the outer circumferential flow passage portion 141 is larger than the width dimension at any position of the inner circumferential flow passage portion 142 (D4>D1, D4>D2, D4>D3). In other words, the width dimension D4 of the outer circumferential flow passage portion 141 is larger than the width dimensions D1, D2, and D3 of the inner circumferential flow passage portion 142.

The first connecting portion 143A connects one end of the first arc portion 142A to one end of the second arc portion 142B. In this embodiment, one end of the first arc portion 142A and one end of the second arc portion 142B are arranged side by side in the radial direction. The first connecting portion 143A connects the first arc portion 142A to the second arc portion 142B in a manner that bends back in a hairpin shape, i.e., in a U-shape. The width dimension of the first connecting portion 143A gradually decreases from the end on the first arc portion 142A side toward the end on the second arc portion 142B side.

The first connecting portion 143A is curved and has opposing side surfaces, i.e., an inner corner surface 144 and an outer corner surface 145. The inner corner surface 144 is a semicircular arc surface centered on a center point C1. The outer corner surface 145 is a semicircular arc surface centered on a center point C2. The radius of curvature of the inner corner surface 144 is smaller than the radius of curvature of the outer corner surface 145. The center point C1 of the inner corner surface 144 and the center point C2 of the outer corner surface 145 are located at different positions. In other words, the inner corner surface 144 and the outer corner surface 145 are arc surfaces with different centers. As a result, the first connecting portion 143A smoothly connects the first arc portion 142A and the second arc portion 142B, which have different width dimensions.

The second connecting portion 143B connects the other end of the first arc portion 142A to one end of the third arc portion 142C. The second connecting portion 143B connects the first arc portion 142A to the third arc portion 142C so as to bend back in a hairpin shape. The second connecting portion 143B extends along the first connecting portion 143A with a larger radius of curvature than the first connecting portion 143A. The second connecting portion 143B gradually reduces in width from the end on the first arc portion 142A side to the end on the third arc portion 142C side. The second connecting portion 143B has an inner corner surface and an outer corner surface that have the same relationship as the first connecting portion 143A, thereby smoothly connecting the first arc portion 142A to the third arc portion 142C.

The third connecting portion 143C connects the other end of the second arc portion 142B to one end of the outer circumferential flow passage portion 141. The third connecting portion 143C connects the second arc portion 142B to the outer circumferential flow passage portion 141 so as to bend back in a hairpin shape. The third connecting portion 143C extends along the second connecting portion 143B with a larger radius of curvature than the second connecting portion 143B. The third connecting portion 143C gradually increases in width from the end on the second arc portion 142B side to the end on the outer circumferential flow passage portion 141 side. The third connecting portion 143C has inner corner surfaces and outer corner surfaces that have the same relationship as the first connecting portion 143A, thereby smoothly connecting the second arc portion 142B to the outer circumferential flow passage portion 141.

(Wall section)
The wall portion 150 has, from the inside, a first arc-shaped wall 150A, a second arc-shaped wall 150B, and a third arc-shaped wall 150C, each of which has a certain width. The first arc-shaped wall 150A, the second arc-shaped wall 150B, and the third arc-shaped wall 150C extend in an arc shape centered on a central axis J. The first arc-shaped wall 150A, the second arc-shaped wall 150B, and the third arc-shaped wall 150C are also arranged concentrically with the central axis J as the center.

The first arc wall 150A extends in an arc shape for approximately 3/4 of the circumference around the central axis J. The first arc wall 150A is located radially between the first arc portion 142A and the second arc portion 142B and defines them. The first arc wall 150A has a uniform radial dimension over its entire length.

The second arc wall 150B extends in an arc shape for approximately 3/4 of the circumference around the central axis J. The second arc wall 150B is located radially between the second arc portion 142B and the third arc portion 142C and defines them. The second arc wall 150B has a uniform radial dimension over its entire length.

The third arc wall 150C extends in an arc shape for approximately 3/4 of the circumference around the central axis J. The third arc wall 150C is located radially between the third arc portion 142C and the outer peripheral flow passage portion 141, and defines them. The third arc wall 150C has a uniform radial dimension over its entire length.

The radial dimension E2 of the second arc wall 150B is smaller than the radial dimension E1 of the first arc wall 150A (E2<E1). The radial dimension E3 of the third arc wall 150C is smaller than the radial dimension E2 of the second arc wall 150B (E3<E2). That is, among the multiple arc walls 150A, 150B, and 150C, the arc wall located radially outward from the other arc walls has a smaller radial dimension than the other arc walls (E3<E2<E1). The wall portion 150 preferably also has a circular wall portion located at the center surrounded by the first arc portion 142A, a substantially semicircular wall portion surrounded by the first connecting portion 143A, a wall portion located between the first connecting portion 143A and the second connecting portion 143B, and a wall portion located between the second connecting portion 143B and the third connecting portion 143C.

In this modified coolant flow path 140, a first flow path portion 140N having the above-mentioned relationship and a second flow path portion 140W connected to the first flow path portion 140N may be provided near the through hole 80, as in the above embodiment. With this configuration, the flow path cross-sectional area is narrowed around the through hole 80. Therefore, the flow velocity of the coolant in the coolant flow path 140 is higher in the first flow path portion 140N, which has a smaller flow path cross-sectional area, compared to the second flow path portion 140W, which has a larger flow path cross-sectional area, and the cooling performance in the first flow path portion 140N is improved. As a result, an electrostatic chuck device 1 with high thermal uniformity can be provided.

Furthermore, according to the base portion 103 of this modified example, as in the above embodiment, the flow path cross-sectional area of the inner circumferential flow path portion 142 decreases with increasing distance from the central axis J, so that the flow rate increases with increasing distance from the central axis J, improving the cooling capacity in the area away from the central axis J and improving the thermal uniformity of the mounting surface 11a of the electrostatic chuck portion 2. Further, according to the base portion 103 of this modified example, as in the above embodiment, the flow path cross-sectional area of the outer circumferential flow path portion 141 is larger than the flow path cross-sectional area of the inner circumferential flow path portion 142. This allows the electrostatic chuck portion 2 to be sufficiently cooled.

The above describes preferred embodiments of the present invention with reference to the attached drawings, but it goes without saying that the present invention is not limited to these examples. The shapes and combinations of the components shown in the above examples are merely examples, and various modifications can be made based on design requirements, etc., without departing from the spirit of the present invention.

For example, in the above-described embodiment and modified example, the flow path cross-sectional area of the inner circumferential flow path portion 42, 142 is made smaller with increasing distance from the central axis J, and the flow path cross-sectional area of the outer circumferential flow path portion 41, 141 is made larger than the flow path cross-sectional area of the inner circumferential flow path portion 42, 142, but this is not limited to the above. For example, even if the flow path cross-sectional area is constant in the outer circumferential flow path portion 41, 141 and the inner circumferential flow path portion 42, 142, the configuration as shown above may be applied around the through hole 80.
Although the above embodiment has been described with the coolant flow passage having a rectangular cross section and a uniform axial dimension over the entire length, the cross-sectional shape of the coolant flow passage is not limited to the above embodiment. For example, the cross-sectional area of the coolant flow passage may be changed by varying the axial dimension of the coolant flow passage.

1 ... electrostatic chuck device 2 ... electrostatic chuck portion 3, 103 ... base portion 3a ... support surface 3b ... bottom surface 4 ... adhesive 5 ... heater element 8 ... adhesive layer 11 ... mounting plate 11a ... mounting surface 11b ... multiple protrusions 12 ... support plate 13 ... electrostatic attraction electrode 14 ... insulating material layer 17 ... peripheral wall 31g ... groove 35 ... upper member 36 ... lower member 40, 140 ... refrigerant flow path 40a, 140a ... inlet 40b, 140b of flow path ... outlet 40g of flow path, 40h... Inner surface of second flow path portion 40j, 40k... Connection surface between first flow path portion and second flow path portion 40N, 140N... First flow path portion 40W, 140W... Second flow path portion 40s... First inner surface of first flow path portion 40t... Second inner surface of first flow path portion 41, 141... Outer peripheral flow path portion 42, 142... Inner peripheral flow path portion 50, 150... Wall portion 50A... Inner peripheral region 50B... Outer peripheral region 80... Through hole 80f... Hole inner peripheral surface 142A... First arc portion (flow path portion)
142B: second arcuate portion (flow passage portion)
142C: Third arc portion (flow path portion)
143A: First connecting portion (flow path portion)
143B: Second connecting portion (flow path portion)
143C...Third connecting portion (flow path portion)
144: inner corner surface of the first connecting portion; 145: outer corner surface of the first connecting portion; 150: wall portion; 150A: first arc wall (wall portion);
150B: Second arc wall (wall portion)
150C...Third arc wall (wall portion)
C1, C2...center point D1...width dimension D2 of first arcuate portion...width dimension D3 of second arcuate portion...width dimension D4 of third arcuate portion...width dimension E1 of outer peripheral flow passage portion...radial dimension E2 of first arcuate wall...radial dimension E3 of second arcuate wall...radial dimension Dx of third arcuate wall...axial dimension J of refrigerant flow passage...center axis L1...two-dot chain line P1...wall portion P2 around through hole...portion T where refrigerant flow passage is formed...thickness W...plate-shaped sample,
Wa: Outer edge of plate-shaped sample Wn: Width dimension Ww: Width dimension θ: Angle centered on the center of the through hole

Claims (9)

a plate-shaped electrostatic chuck portion having a mounting surface on which a plate-shaped sample is mounted and having an electrode for electrostatic attraction provided therein;
a base portion having a disk shape centered on a central axis line and configured to support the electrostatic chuck portion on a support surface opposite to the placement surface,
The base portion is
At least one through hole penetrating the base portion in an axial direction of the central axis;
a coolant flow path provided inside the base portion and extending along the support surface;
The refrigerant flow path is
A first flow path portion and a second flow path portion respectively connected to both ends of the first flow path portion,
The first flow path portion is formed at a distance from the through hole, on the outer side of the through hole in a hole diameter direction, with the through hole as a center,
The second flow path portions are located on both sides of the first flow path portion in an extension direction of the refrigerant flow path,
The flow path cross-sectional area of the first flow path portion is smaller than the flow path cross-sectional area of the second flow path portion.
Electrostatic chuck device. The first flow path portion has a smaller width dimension in a direction intersecting the axial direction and the extension direction than the second flow path portion.
2. The electrostatic chuck device of claim 1. The flow path cross-sectional area of the first flow path portion is 0.5 times or more and less than 1.0 times the flow path cross-sectional area of the second flow path portion.
3. The electrostatic chuck device according to claim 1 or 2. The first flow path portion has a first inner surface and a second inner surface facing each other,
The first inner surface is formed at a distance from the through hole on the outer side in the hole radial direction of the through hole and faces the outer side in the hole radial direction,
The second inner surface is formed outwardly of the first inner surface in the hole radial direction and spaced apart from the first inner surface, and faces inwardly in the hole radial direction,
The electrostatic chuck device according to claim 1 , wherein the first inner surface is formed in an arc shape that is concentric with an inner circumferential surface of the through hole. The electrostatic chuck device according to claim 4, wherein the second inner surface is formed in an arc shape concentric with the inner peripheral surface of the through hole. The first inner surface and the second inner surface are formed in a range of 20 to 300° around the through hole when viewed in the axial direction.
6. The electrostatic chuck device according to claim 5. In the second flow path portion located on at least one side of the first flow path portion in the extension direction of the refrigerant flow path, a connection surface that is curved in an arc shape when viewed in the axial direction is formed between an inner surface of the second flow path portion that is connected to the first inner surface and the first inner surface.
5. The electrostatic chuck device according to claim 4. The thickness of the wall portion formed between the inner circumferential surface of the through hole and the first inner side surface is 1 mm or more and 10 mm or less.
5. The electrostatic chuck device according to claim 4. The refrigerant flow path has a continuous spiral shape in a plan view,
The base portion further includes a wall portion that defines the coolant flow path,
The through hole has a circular shape in a plan view and penetrates at least a portion of the wall portion in the axial direction.
the wall portion has a first portion in which the through hole is provided and a second portion located on both sides of the first portion in which no through hole is provided,
The width of the first portion is greater than the width of the second portion in a plan view,
the width of the first portion varies gradually;
A side surface of the first portion forms an inner surface of the first flow passage, and a side surface of the second portion forms an inner surface of the second flow passage.
2. The electrostatic chuck device of claim 1.

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