Electrostatic chuck device

Abstract

To provide an electrostatic chuck device with high heat uniformity. [Solution] 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 electrostatic adsorption electrodes provided inside; and a base portion that is disc-shaped with a central axis and supports the electrostatic chuck portion from the opposite side of the mounting surface on a support surface, wherein a refrigerant flow path is provided inside the base portion, extending along the support surface, and the base portion has a wall portion that divides the refrigerant flow path radially and defines it in a spiral shape with a central axis, the radial dimension of the wall portion decreasing as it moves away from the central axis.

Description

Technical Field

[0001] The present invention relates to an electrostatic chuck device.

Background Art

[0002] In semiconductor manufacturing apparatuses using plasma, such as plasma etching apparatuses and plasma CVD apparatuses, an electrostatic chuck device is used as a device for easily attaching and fixing a wafer to a mounting surface and maintaining the wafer at a desired temperature. Patent Document 1 discloses a configuration including a plate-shaped ceramic body including a mounting surface and a base member provided with a cooling passage through which a cooling medium flows inside.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, devices using semiconductors tend to be highly integrated. Therefore, at the time of manufacturing the devices, microfabrication techniques for wiring and three-dimensional mounting techniques are required. In carrying out such processing techniques, semiconductor manufacturing apparatuses are required to reduce the in-plane temperature distribution (temperature difference) of the wafer. In the prior art, it may not be possible to reduce the in-plane temperature distribution of the wafer to a desired temperature difference, and improvement has been demanded.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide an electrostatic chuck device having high heat uniformity.

Means for Solving the Problems

[0006] That is, the present invention includes the inventions of the following [1] to [6]. The following inventions may be combined in two or more ways as needed. [1] 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 electrostatic adsorption electrodes provided inside; and a base portion which is disc-shaped with respect to a central axis and supports the electrostatic chuck portion from the opposite side of the mounting surface on a support surface, wherein a refrigerant flow path is provided inside the base portion which extends along the support surface, and the base portion has a wall portion which divides the refrigerant flow path radially and defines a spiral shape with respect to the central axis, the radial dimension of the wall portion which decreases as it moves away from the central axis. [2] The electrostatic chuck device according to [1], wherein the wall portion is continuously spaced away from the central axis while increasing the radius of curvature along the circumferential direction, and the radial dimension is continuously decreased as it moves radially outward. [3] The electrostatic chuck device according to [1] or [2], wherein the wall portion has a plurality of arc-shaped walls that extend in an arc shape with respect to the central axis and are arranged concentrically, and the arc-shaped walls located radially outward among the plurality of arc-shaped walls have a smaller radial dimension than the arc-shaped walls located radially inward. [4] The wall portion has a first circular arc wall, a second circular arc wall, and a third circular arc wall that extend in an arc shape around the central axis and are arranged concentrically, The first circular arc wall, the second circular arc wall, and the third circular arc wall each have a uniform radial dimension along their entire length. The refrigerant flow path is The first arc portion of the refrigerant flow path, A second arc portion located radially outward from the first arc portion, A third arc portion located radially outward from the second arc portion, The third arc portion has an outer peripheral flow channel located radially outward, The first arc portion, the second arc portion, the third arc portion, and the outer peripheral flow channel portion are arranged concentrically with respect to the central axis and each extends in an arc shape. The first circular arc wall is located radially between the first circular arc portion and the second circular arc portion. The second circular arc wall is located radially between the second circular arc portion and the third circular arc portion. The third circular arc wall is located radially between the third circular arc portion and the outer peripheral flow channel portion. The radial dimension of the second circular arc wall is smaller than the radial dimension of the first circular arc wall. The electrostatic chuck device according to [1], wherein the radial dimension of the third arc wall is smaller than the radial dimension of the second arc wall. [5] The electrostatic chuck device according to [4], wherein the first arc wall, the second arc wall, and the third arc wall each extend in an arc shape for at least 3 / 4 of a turn with respect to the central axis. [6] The refrigerant flow path is A first connecting portion that connects one end of the first arc portion and one end of the second arc portion by folding them back in a hairpin shape, A second connecting portion that connects the other end of the first arc portion and one end of the third arc portion by folding them back in a hairpin shape, The electrostatic chuck device according to [4] or [5], having a third connecting portion which connects the other end of the second arc portion and one end of the outer peripheral flow channel portion by folding them back in a hairpin shape. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide an electrostatic chuck device with high heat uniformity. [Brief explanation of the drawing]

[0008] [Figure 1] This is a cross-sectional view showing an electrostatic chuck device according to the first embodiment. [Figure 2] This is a schematic diagram showing the refrigerant flow path of the first embodiment. [Figure 3] This is a schematic diagram showing the refrigerant flow path of the second embodiment. [Modes for carrying out the invention]

[0009] The electrostatic chuck device according to this embodiment will be described below based on the drawings. Note that in all the following drawings, the dimensions and proportions of each component have been appropriately altered for clarity.

[0010] In this specification, the "degree of in-plane temperature distribution (temperature difference) of the electrostatic chuck portion (or mounting surface)" may be referred to as "thermal uniformity". "High thermal uniformity" means that the in-plane temperature distribution in the region of the mounting surface of the electrostatic chuck portion where the plate-shaped sample is mounted is small.

[0011] <First Embodiment> FIG. 1 is a cross-sectional view showing the electrostatic chuck device 1 of the first embodiment. The electrostatic chuck device 1 includes a plate-shaped electrostatic chuck portion 2, a heater element 5, and a disk-shaped base portion 30. The electrostatic chuck device 1 has a disk shape centered on the central axis J. The electrostatic chuck portion 2, the heater element 5, and the base portion 30 are laminated in this order along the axial direction of the central axis J.

[0012] In the following description, the directions of each part of the electrostatic chuck device 1 are described with the central axis J as the center. 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". Further, in the following description, the vertical direction of each part is defined in a posture where the direction in which the central axis J extends coincides with the vertical direction. However, the posture of the electrostatic chuck device 1 during use is not limited.

[0013] (Electrostatic Chuck Portion) The electrostatic chuck portion 2 includes a mounting plate 11 having an upper surface as a mounting surface 11a for mounting a circular plate-shaped sample W such as a semiconductor wafer, a support plate 12 integrated with the mounting plate 11 and supporting the bottom side of the mounting plate 11, an electrostatic adsorption electrode 13 provided between the mounting plate 11 and the support plate 12, and an insulating material layer 14 that insulates the periphery of the electrostatic adsorption electrode 13. That is, the electrostatic chuck portion 2 has a mounting surface 11a for mounting the plate-shaped sample W and an electrostatic adsorption electrode 13 is provided inside.

[0014] The mounting plate 11 and the support plate 12 are disk-shaped members having the same shape on the overlapping surfaces. The mounting plate 11 and the support plate 12 are made of a ceramic sintered body having mechanical strength and durability against corrosive gases and their plasmas. The mounting plate 11 and the support plate 12 will be described in detail later.

[0015] On the mounting surface 11a of the mounting plate 11, a plurality of protrusions 11b having a diameter smaller than the thickness of the plate-like sample are formed at a plurality of predetermined intervals, and these protrusions 11b support the plate-like sample W.

[0016] Also, a peripheral wall 17 is formed at the periphery of the mounting surface 11a. The peripheral wall 17 is formed at the same height as the protrusions 11b and supports the plate-like sample W together with the protrusions 11b.

[0017] The electrostatic adsorption electrode 13 is used as an electrostatic chuck electrode for generating charges and fixing the plate-like sample W by electrostatic adsorption force. The shape and size of the electrostatic adsorption electrode 13 are appropriately adjusted according to its use.

[0018] The electrostatic adsorption electrode 13 can be composed of an arbitrarily selected material. For example, it is preferably formed of a conductive ceramic such as an aluminum oxide - tantalum carbide (Al2O3 - Ta4C5) conductive composite sintered body, an aluminum oxide - tungsten (Al2O3 - W) conductive composite sintered body, an aluminum oxide - silicon carbide (Al2O3 - SiC) conductive composite sintered body, an aluminum nitride - tungsten (AlN - W) conductive composite sintered body, an aluminum nitride - tantalum (AlN - Ta) conductive composite sintered body, a yttrium oxide - molybdenum (Y2O3 - Mo) conductive composite sintered body, or a high melting point metal such as tungsten (W), tantalum (Ta), molybdenum (Mo).

[0019] The electrostatic adsorption electrode 13 can be easily formed by a film formation method such as a sputtering method or a vapor deposition method, or a coating method such as a screen printing method.

[0020] The insulating layer 14 surrounds the electrostatic adsorption electrode 13, protecting it from corrosive gases and their plasma. The insulating layer 14 also joins and integrates the boundary between the mounting plate 11 and the support plate 12, i.e., the outer peripheral region other than the electrostatic adsorption electrode 13. The insulating layer 14 is made of an insulating material with the same composition or the same main component as the materials constituting the mounting plate 11 and the support plate 12.

[0021] (Heater element) The heater element 5 heats the electrostatic chuck portion 2. The heater element 5 is positioned on the lower side of the electrostatic chuck portion 2. The structure and material of the heater element 5 can be arbitrarily selected. For example, a non-magnetic metal sheet having a constant thickness of 0.2 mm or less, preferably about 0.1 mm, such as a titanium (Ti) sheet, a tungsten (W) sheet, or a molybdenum (Mo) sheet, can be processed by photolithography or laser processing to obtain a desired heater shape, such as a meandering shape of a strip-shaped conductive sheet with an overall contour of an annular shape.

[0022] The heater element 5 may be provided by bonding a thin non-magnetic metal plate to the electrostatic chuck portion 2 and then processing and molding it on the surface of the electrostatic chuck portion 2. Alternatively, the heater element 5 may be separately processed and molded at a different location from the electrostatic chuck portion 2 and then transferred and printed onto the surface of the electrostatic chuck portion 2.

[0023] The heater element 5 is bonded and fixed to the bottom surface of the support plate 12 by an adhesive 4 made of a sheet-like or film-like silicone resin or acrylic resin, which has uniform thickness and heat resistance and insulating properties.

[0024] The electrostatic chuck portion 2 and the base portion 30 are bonded together via an adhesive layer 8 provided between them. The adhesive layer 8 is formed, for example, from a cured body obtained by heat-curing a silicone resin composition or from an acrylic resin. Preferably, the adhesive layer 8 is formed by, for example, placing a fluid resin composition between the electrostatic chuck portion 2 and the base portion 30 and then heat-curing it. This fills any irregularities between the electrostatic chuck portion 2 and the base portion 30 with the adhesive layer 8, making it less likely for voids or defects to occur in the adhesive layer 8. As a result, the thermal conductivity characteristics of the adhesive layer 8 can be made uniform across the surface, improving the uniformity of the heat distribution of the electrostatic chuck portion 2.

[0025] (Base section) The base portion 30 cools the electrostatic chuck portion 2. The base portion 30 is disc-shaped with a central axis J at its center. The base portion 30 has a support surface 3a that supports the electrostatic chuck portion 2 and a bottom surface 3b that faces the opposite side of the support surface 3a. The electrostatic chuck portion 2 is supported on the support surface 3a from the opposite side of the mounting surface 11a.

[0026] The material constituting the base portion 30 is not particularly limited as long as it is a metal or composite material containing such metals that has excellent thermal conductivity, electrical conductivity, and workability. For example, aluminum (Al), aluminum alloys, copper (Cu), titanium (Ti), copper alloys, stainless steel (SUS), etc., are preferably used. At least the surface of the base portion 30 that is exposed to the plasma is preferably anodized or has an insulating film such as alumina deposited on it.

[0027] A refrigerant flow path 40 is provided inside the base portion 30. The refrigerant flow path 40 is provided with an inlet 40a for drawing refrigerant into the refrigerant flow path 40 from outside the base portion 30, and an outlet 40b for discharging the refrigerant in the refrigerant flow path 40 to the outside of the base portion 30. The inlet 40a and outlet 40b open to the bottom surface 3b of the base portion 30. Note that in Figure 1, the radial positions of the inlet 40a and outlet 40b are schematically shown and do not represent their actual arrangement.

[0028] 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 cross-section throughout its entire length. In this embodiment, the axial dimension Dx of the refrigerant flow path 40 is uniform throughout its entire length. The refrigerant flow path 40 has an upper member 35 and a lower member 36. The upper member 35 is a plate-shaped member with its thickness oriented axially. The lower member 36 is a plate-shaped member with a greater axial thickness dimension than the upper member 35.

[0029] The upper surface of the lower member 36 is provided with a groove 31g that opens upward. In the lower member 36, the portion between the grooves 31g constitutes a wall portion 50. That is, the base portion 30 has a wall portion 50. The wall portion 50 separates the grooves 31g.

[0030] The opening of the groove 31g is covered by the upper member 35. The refrigerant flows into the region enclosed by the inner surface of the groove 31g and the upper member 35. In other words, the refrigerant flow path 40 is formed in the region enclosed by the inner surface of the groove 31g and the lower surface of the upper member 35. The wall portion 50 also divides the refrigerant flow path 40 in the radial direction. The lower surface of the upper member 35 and the upper surface of the lower member 36 are joined to each other by a joining means such as brazing.

[0031] Figure 2 is a schematic diagram of the refrigerant flow path 40 in this embodiment. In this embodiment, the refrigerant flow path 40 is spiral-shaped, extending radially outward with respect to the central axis J. The refrigerant flow path 40 in this embodiment is continuous along its entire length. In this embodiment, the refrigerant flow path 40 continuously moves away from the central axis J while increasing the radius of curvature along the circumferential direction. Wall portions 50 are located between radially overlapping portions of the refrigerant flow path 40. The wall portions 50 define the refrigerant flow path 40 in a spiral shape centered on the central axis J.

[0032] The refrigerant flow path 40 has an outer circumferential flow path section 41 and an inner circumferential flow path section 42. The outer circumferential flow path section 41 is located in the outermost region of the total length of the refrigerant flow path 40 and extends circumferentially by one turn or less around the central axis J. On the other hand, the inner circumferential flow path section 42 is located radially inward of the outer circumferential flow path section 41 of the total length of the refrigerant flow path 40. The outer circumferential flow path section 41 and the inner circumferential flow path section 42 are connected to each other. In this embodiment, the inlet 40a is provided in the outer circumferential flow path section 41 and the outlet 40b is provided in the inner circumferential flow path section 42. Therefore, in this embodiment, the refrigerant flows through the refrigerant flow path 40 in the order of the outer circumferential flow path section 41 and then the inner circumferential flow path section 42.

[0033] The outer peripheral channel section 41 is located at the outermost periphery of the refrigerant channel 40. The outer peripheral channel section 41 extends in an arc shape for approximately 3 / 4 of its circumference with respect to the central axis J. An inlet 40a is provided at one end of the outer peripheral channel section 41. The other end of the outer peripheral channel section 41 is connected to the inner peripheral channel section 42. When viewed from the axial direction, the outer peripheral channel section 41 overlaps with the outer edge Wa of the plate-shaped sample W.

[0034] The outer peripheral flow channel 41 has a uniform width dimension along its entire length. In this embodiment, the refrigerant flow channel 40 has a rectangular flow channel cross-section along its entire length, and its axial dimension is uniform. Therefore, the outer peripheral flow channel 41 has a uniform flow channel cross-sectional area along its entire length.

[0035] The inner circumferential channel section 42 is spiral-shaped, extending in a rotation of approximately one and a half turns around the central axis J. One end of the inner circumferential channel section 42 is connected to the outer circumferential channel section 41. An outlet 40b is provided at the other end of the inner circumferential channel section 42.

[0036] The width of the inner circumferential flow channel 42 decreases continuously as it extends radially outward. As a result, the cross-sectional area of ​​the flow channel in the inner circumferential flow channel 42 decreases continuously as it extends radially outward.

[0037] The wall portion 50 is spiral-shaped, extending in a rotation of approximately 1 and 3 / 4 turns around the central axis J. In this embodiment, the wall portion 50 continuously moves away from the central axis J while increasing its radius of curvature along the circumferential direction. The wall portion 50 is located between the inner circumferential flow channels 42 in the inner circumferential region 50A and defines them. The wall portion 50 is also located between the outer circumferential flow channel 41 and the inner circumferential flow channel 42 in the outer circumferential region 50B and defines them.

[0038] The radial dimension of the wall portion 50 decreases continuously as it moves away from the central axis J. Therefore, the radial distance between portions of the refrigerant flow path 40 that overlap radially decreases continuously as they move away from the central axis J.

[0039] (Other configurations) The electrostatic chuck device 1 may have a gas supply hole (not shown) and a lift pin insertion hole that penetrate the electrostatic chuck portion 2 in the axial direction. The gas supply hole and the lift pin insertion hole open to the mounting surface 11a. A cooling gas such as He is supplied to the gas supply hole. The cooling gas introduced from the gas introduction 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, cooling the plate-shaped sample W. A lift pin (not shown) is inserted through the lift pin insertion hole to support the plate-shaped sample W and move the plate-shaped sample W up and down.

[0040] (Effects of the first embodiment) In this embodiment, the outer circumferential channel section 41 overlaps with the outer edge Wa of the plate-shaped sample W when viewed from the axial direction of the central axis J. In addition, the inner circumferential channel section 42 in this embodiment is positioned radially inward from the outer circumferential channel section 41. The base section 30 maintains a constant temperature of the plate-shaped sample W by actively cooling the region of the electrostatic chuck section 2 that overlaps with the plate-shaped sample W when viewed from the axial direction. According to this embodiment, the inner circumferential channel section 42 is positioned inside the outer edge Wa of the plate-shaped sample when viewed from the axial direction and cools the region of the electrostatic chuck section 2 that overlaps with the plate-shaped sample W when viewed from the axial direction. On the other hand, the outer circumferential channel section 41 cools the electrostatic chuck section 2 at the boundary between the inner and outer regions of the outer edge Wa of the plate-shaped sample W when viewed from the axial direction. According to this embodiment, by providing the inner circumferential channel section 42 and the outer circumferential channel section 41 and optimizing the respective channel configurations, the uniformity of the heat distribution of the electrostatic chuck section 2 can be improved up to the vicinity of the outer edge Wa of the plate-shaped sample W.

[0041] In this embodiment, at least a portion of the inner circumferential flow path 42 extends in a spiral shape around the central axis J. Furthermore, the cross-sectional area of ​​the inner circumferential flow path 42 decreases as it moves away from the central axis J. The flow velocity of the refrigerant in the flow path increases as the cross-sectional area of ​​the flow path decreases, and consequently, the frequency of collisions between the refrigerant molecules and the inner surface of the flow path increases, leading to more active heat transfer. On the other hand, in the spiral-shaped inner circumferential flow path 42, the radius of curvature decreases as it approaches the central axis J, resulting in greater pressure loss, and consequently, more active heat transfer between the refrigerant and the inner surface of the flow path. According to this embodiment, the decrease in cooling capacity due to the increase in the radius of curvature of the inner circumferential flow path 42 as it moves away from the central axis J can be offset by the increase in cooling capacity due to the reduction in the cross-sectional area of ​​the flow path. This reduces the difference in cooling capacity between the region close to the central axis J and the region further away. In other words, according to this embodiment, by reducing the cross-sectional area of ​​the inner circumferential flow channel 42 radially outward, the cooling capacity of the base 30 is increased in the region away from the central axis J, thereby improving the uniformity of heat on the mounting surface 11a of the electrostatic chuck 2.

[0042] In this embodiment, the width of the inner circumferential flow path 42 decreases as it moves away from the central axis J. That is, according to this embodiment, the flow path cross-sectional area of ​​the inner circumferential flow path 42 is changed by the change in the width dimension. For this reason, the inner circumferential flow path 42 in this embodiment can have a rectangular cross-sectional shape, and the dimensions along the axial direction of the inner circumferential flow path 42 can be made uniform. According to this embodiment, the refrigerant flow path 40 can be manufactured by machining a groove 31g (see Figure 1) of uniform depth using a tool such as an end mill, and the manufacturing process of the base portion 30 can be simplified.

[0043] In this embodiment, the inner circumferential flow channel 42 is continuously spaced away from the central axis J while increasing the radius of curvature along the circumferential direction, and its width is continuously reduced as it moves radially outward. According to this embodiment, by making the inner circumferential flow channel 42 spiral in shape with a continuously increasing radius of curvature along the circumferential direction, the inner circumferential flow channel 42 can be densely and uniformly arranged. As a result, the electrostatic chuck 2 can be uniformly cooled by the base 30, and the uniformity of the heat distribution on the mounting surface 11a of the electrostatic chuck 2 can be improved. In addition, in this embodiment, the width of the inner circumferential flow channel 42 is continuously reduced as the radius of curvature increases. As a result, the cooling capacity of the inner circumferential flow channel 42 can be continuously changed, suppressing the occurrence of singularities in the cooling capacity and improving the uniformity of the heat distribution on the mounting surface 11a of the electrostatic chuck 2.

[0044] In this embodiment, the cross-sectional area of ​​the outer peripheral channel section 41 is larger than the cross-sectional area of ​​the inner peripheral channel section 42. Therefore, the width dimension of the outer peripheral channel section 41 is larger than the width dimension of the inner peripheral channel section 42. Since the outer peripheral channel section 41 overlaps the outer edge Wa of the plate-shaped sample W when viewed from the axial direction, the plate-shaped sample W is not placed directly above the portion radially outside the outer edge Wa. Therefore, even if the cross-sectional area of ​​the outer peripheral channel section 41 is increased in the portion radially outside the outer edge Wa, the electrostatic chuck section 2 directly above it can be sufficiently cooled.

[0045] In the base portion 30 of this embodiment, the radial dimension of the wall portion 50 decreases as it moves away from the central axis J. As the radial dimension of the wall portion 50 decreases, the distance between the refrigerant flow paths 40 that are aligned radially through the wall portion 50 decreases. In other words, as the radial dimension of the wall portion 50 decreases, the density of the refrigerant flow paths 40 increases, and the cooling capacity of that region increases. According to this embodiment, by making the radial dimension of the wall portion 50 smaller on the radially outer side, the cooling capacity of the region away from the central axis J can be increased, and the uniformity of the heat distribution on the mounting surface 11a of the electrostatic chuck portion 2 can be increased.

[0046] In particular, in this embodiment, the wall portion 50 is continuously spaced away from the central axis J while increasing the radius of curvature along the circumferential direction, and its radial dimension is continuously decreased as it moves radially outward. This makes it possible to continuously change the cooling capacity of the inner circumferential flow channel portion 42 radially outward, and improve the uniformity of heat on the mounting surface 11a of the electrostatic chuck portion 2.

[0047] In this embodiment, the inlet 40a is provided at the radially outer end of the refrigerant flow path 40, and the outlet 40b is provided at the radially inner end of the refrigerant flow path 40. Therefore, the refrigerant in the refrigerant flow path 40 flows in a spiral shape from the radially outer end to the radially inner end. As described above, the refrigerant flow path 40 needs to have increased cooling capacity in regions that are far from the central axis J and have a large radius of curvature. According to this embodiment, the uniformity of the heat distribution in the electrostatic chuck section 2 can be improved by passing a lower-temperature refrigerant through the radially outer region where cooling is highly necessary.

[0048] <Second Embodiment> Figure 3 is a schematic diagram of the refrigerant flow path 140 of the second embodiment. The refrigerant flow path 140 of the second embodiment will be described below based on Figure 3. Note that components similar to those in the above-described embodiment are denoted by the same reference numerals, and detailed explanations are omitted.

[0049] The refrigerant flow path 140 in this embodiment is a double spiral that folds 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 in this embodiment is continuous along its entire length. The refrigerant flow path 140 in this embodiment has a rectangular cross-section along its entire length, and its axial dimensions are 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 as a spiral shape centered on the central axis J.

[0050] The refrigerant flow path 140 has an outer circumferential flow path section 141 and an inner circumferential flow path section 142 that is located radially inward from the outer circumferential flow path section 141. The outer circumferential flow path section 141 and the inner circumferential flow path section 142 are connected to each other. In this embodiment, the inlet 140a is provided in the inner circumferential flow path section 142, and the outlet 140b is provided in the outer circumferential flow path section 141. Therefore, in this embodiment, the refrigerant flows through the refrigerant flow path 40 in the order of the inner circumferential flow path section 142 and then the outer circumferential flow path section 141.

[0051] The outer peripheral channel section 141 is located at the outermost periphery of the refrigerant channel 140. The outer peripheral channel section 141 extends in an arc shape for approximately 3 / 4 of its circumference with respect to the central axis J. The inner peripheral channel section 142 is connected to one end of the outer peripheral channel section 141. An outlet 140b is provided at the other end of the outer peripheral channel section 141. Furthermore, the outer peripheral channel section 141 overlaps with the outer edge Wa of the plate-shaped sample W when viewed from the axial direction. The outer peripheral channel section 141 has a uniform width dimension along its entire length. Therefore, the outer peripheral channel section 141 has a uniform channel cross-sectional area along its entire length.

[0052] The inner circumferential flow channel 142 has a first arc section 142A, a second arc section 142B, a third arc section 142C, a first connecting section 143A, a second connecting section 143B, and a third connecting section 143C. The first arc section 142A, the second arc section 142B, and the third arc section 142C extend in an arc shape with respect to the central axis J. The first arc section 142A, the second arc section 142B, and the third arc section 142C are arranged concentrically with respect to the central axis J.

[0053] The first arc section 142A is located at the innermost circumference of the inner circumferential flow channel section 142. The first arc section 142A extends in an arc shape for approximately 3 / 4 of a turn with respect to the central axis J. The first connecting section 143A is connected to one end of the first arc section 142A. The second connecting section 143B is connected to the other end of the first arc section 142A. The width dimension of the first arc section 142A is uniform along its entire length. Therefore, the flow channel cross-sectional area of ​​the first arc section 142A is uniform along its entire length.

[0054] The second arc section 142B is located radially outward from the first arc section 142A. In the radial direction, the second arc section 142B is located between the first arc section 142A and the third arc section 142C. The second arc section 142B extends in an arc shape for approximately 3 / 4 of a turn with respect to the central axis J. The first connecting section 143A is connected to one end of the second arc section 142B. The third connecting section 143C is connected to the other end of the second arc section 142B. The width dimension of the second arc section 142B is uniform along its entire length. Therefore, the flow path cross-sectional area of ​​the second arc section 142B is uniform along its entire length.

[0055] The third arc section 142C is located radially outward from the second arc section 142B. In the radial direction, the third arc section 142C is located between the second arc section 142B and the outer peripheral flow channel section 141. The third arc section 142C extends in an arc shape for approximately 3 / 4 of a turn with respect to the central axis J. The second connecting section 143B is connected to one end of the third arc section 142C. An inlet 140a is provided at the other end of the third arc section 142C. The width dimension of the third arc section 142C is uniform along its entire length. Therefore, the flow channel cross-sectional area of ​​the third arc section 142C is uniform along its entire length.

[0056] 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). Also, 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). That is, among the plurality of arc portions 142A, 142B, 142C, the arc portion located radially outside the other arc portions has a smaller radial dimension than the other arc portions (D3 < D2 < D1). Further, the width dimension D4 of the outer peripheral flow path portion 141 is larger than the width dimension at any position of the inner peripheral flow path portion 142 (D4 > D1, D4 > D2, D4 > D3). That is, the width dimension D4 of the outer peripheral flow path portion 141 is larger than the width dimensions D1, D2, D3 of the inner peripheral flow path portion 142.

[0057] The first connecting portion 143A connects one end of the first arc portion 142A and one end of the second arc portion 142B. In the present 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 and the second arc portion 142B so as to fold back in a hairpin shape. The first connecting portion 143A gradually decreases in width dimension from the end on the first arc portion 142A side toward the end on the second arc portion 142B side.

[0058] The first connecting portion 143A has an inner corner surface 144 and an outer corner surface 145 that face each other. The inner corner surface 144 is a semi-circular arc surface centered on the center point C1. Also, the outer corner surface 145 is a semi-circular arc surface centered on the 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. Also, the center point C1 of the inner corner surface 144 and the center point C2 of the outer corner surface 145 are arranged at different positions from each other. That is, the inner corner surface 144 and the outer corner surface 145 are arc surfaces having different centers. Thereby, the first connecting portion 143A smoothly connects the first arc portion 142A and the second arc portion 142B having different width dimensions.

[0059] The second connecting section 143B connects the other end of the first arc section 142A to one end of the third arc section 142C. The second connecting section 143B connects the first arc section 142A and the third arc section 142C by folding back in a hairpin shape. The second connecting section 143B extends along the first connecting section 143A with a larger radius of curvature than the first connecting section 143A. The width dimension of the second connecting section 143B gradually decreases from the end on the first arc section 142A side to the end on the third arc section 142C side. The second connecting section 143B has an inner corner surface and an outer corner surface similar to the first connecting section 143A, thereby smoothly connecting the first arc section 142A and the third arc section 142C.

[0060] The third connecting section 143C connects the other end of the second arc section 142B to one end of the outer peripheral flow section 141. The third connecting section 143C connects the second arc section 142B and the outer peripheral flow section 141 by folding back in a hairpin shape. The third connecting section 143C extends along the second connecting section 143B with a larger radius of curvature than the second connecting section 143B. The width dimension of the third connecting section 143C gradually increases from the end on the second arc section 142B side to the end on the outer peripheral flow section 141 side. The third connecting section 143C has an inner corner surface and an outer corner surface similar to the first connecting section 143A, thereby smoothly connecting the second arc section 142B and the outer peripheral flow section 141.

[0061] The wall section 150 includes a first circular arc wall 150A, a second circular arc wall 150B, and a third circular arc wall 150C. The first circular arc wall 150A, the second circular arc wall 150B, and the third circular arc wall 150C extend in an arc shape with respect to the central axis J. Furthermore, the first circular arc wall 150A, the second circular arc wall 150B, and the third circular arc wall 150C are arranged concentrically with respect to the central axis J.

[0062] The first arc-shaped wall 150A extends in an arc shape for approximately 3 / 4 of a turn with respect to the central axis J. The first arc-shaped wall 150A is located between the first arc section 142A and the second arc section 142B in the radial direction and defines them. The radial dimensions of the first arc-shaped wall 150A are uniform along its entire length.

[0063] The second arc wall 150B extends in an arc shape for approximately three - quarters of a circle with respect to the central axis J. The second arc wall 150B is located between and defines the second arc portion 142B and the third arc portion 142C in the radial direction. The second arc wall 150B has a uniform radial dimension over its entire length.

[0064] The third arc wall 150C extends in an arc shape for approximately three - quarters of a circle with respect to the central axis J. The third arc wall 150C is located between and defines the third arc portion 142C and the outer peripheral flow path portion 141 in the radial direction. The third arc wall 150C has a uniform radial dimension over its entire length.

[0065] 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). Also, 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 plurality of arc walls 150A, 150B, 150C, the arc wall located radially outside other arc walls has a smaller radial dimension than other arc walls (E3 < E2 < E1).

[0066] (Operational effects of the second embodiment) According to the base portion 103 of the present embodiment, similar to the above - described embodiment, the flow path cross - sectional area of the inner peripheral flow path portion 142 decreases as it moves away from the central axis J, thereby enhancing the cooling capacity in the region away from the central axis J and enhancing the heat uniformity of the mounting surface 11a of the electrostatic chuck portion 2. Also, according to the base portion 103 of the present embodiment, similar to the above - described embodiment, the flow path cross - sectional area of the outer peripheral flow path portion 141 is smaller than the flow path cross - sectional area of the inner peripheral flow path portion 142. Thereby, the electrostatic chuck portion 2 can be sufficiently cooled.

[0067] The inner circumferential flow channel 142 of this embodiment has a plurality of arc sections 142A, 142B, and 142C that extend in an arc shape around the central axis J and are arranged concentrically. Furthermore, the arc sections located radially outward among the plurality of arc sections 142A, 142B, and 142C have a smaller width dimension than the arc sections located radially inward. According to this embodiment, because the plurality of arc sections 142A, 142B, and 142C are arranged concentrically, it is easy to arrange the plurality of arc sections 142A, 142B, and 142C precisely, and the electrostatic chuck section 2 can be cooled uniformly by the base section 103. In addition, by setting the width dimensions D1, D2, and D3 of the arc sections 142A, 142B, and 142C to the above-mentioned relationship (D1>D2>D3), the cooling capacity of the region away from the central axis J can be increased, thereby improving the uniformity of the heat distribution of the electrostatic chuck section 2. In addition, if the width direction of the multiple arc sections 142A, 142B, and 142C is made uniform along the circumferential direction, the manufacturing process of the arc sections 142A, 142B, and 142C can be simplified.

[0068] In the base portion 103 of this embodiment, the wall portion 150 has a plurality of arcuate walls 150A, 150B, and 150C that extend in an arc shape around the central axis J and are arranged concentrically. Among the plurality of arcuate walls 150A, 150B, and 150C, the arcuate wall located radially outward from the other arcuate walls has a smaller radial dimension than the other arcuate walls. According to this embodiment, because the plurality of arcuate walls 150A, 150B, and 150C are arranged concentrically, it is easy to arrange the arcuate walls 150A, 150B, and 150C precisely, and the electrostatic chuck portion 2 can be cooled uniformly by the base portion 103. Furthermore, by setting the radial dimensions E1, E2, and E3 of the arcuate portions 142A, 142B, and 142C to the above-mentioned relationship (E1>E2>E3), the cooling capacity of the region away from the central axis J can be increased, thereby improving the uniformity of the heat distribution of the electrostatic chuck portion 2.

[0069] In this embodiment, one of the inlet 140a and outlet 140b is located on the outermost periphery of the inner circumferential flow path 142, and the other is located on the outer circumferential flow path 141. That is, both the inlet 140a and outlet 140b are positioned biased toward the outer circumferential side of the refrigerant flow path 140. As a result, the inlet 140a and outlet 140b are not positioned near the central axis J of the base portion 103, making it easier to position other components such as through holes near the central axis J. Furthermore, the temperature of the refrigerant in the refrigerant flow path 140 gradually increases as it flows from the inlet 140a to the outlet 140b. According to this embodiment, by positioning both the inlet 140a and outlet 140b biased toward one side in the radial direction, it is possible to suppress the occurrence of a temperature gradient between the radially inside and outside of the electrostatic chuck portion 2 due to the temperature rise of the refrigerant, thereby improving the uniformity of the heat distribution of the electrostatic chuck portion 2.

[0070] Although preferred embodiments of the present invention have been described above with reference to the attached drawings, it goes without saying that the present invention is not limited to these examples. The shapes and combinations of the constituent members shown in the above examples are merely examples, and can be modified in various ways based on design requirements, etc., without departing from the spirit of the present invention.

[0071] For example, in the embodiments described above, the case in which the cross-sectional shape of the refrigerant flow path is rectangular and the axial dimension is uniform along its entire length was explained, but the cross-sectional shape of the refrigerant flow path is not limited to the embodiments described above. For example, the cross-sectional area of ​​the refrigerant flow path may be changed by varying the axial dimension. [Explanation of symbols]

[0072] 1...Electrostatic chuck device, 2...Electrostatic chuck part, 30, 103...Base part, 3a...Support surface, 11a...Placement surface, 13...Electrostatic adsorption electrode, 40, 140...Refrigerant flow path, 41, 141...Outer peripheral flow path part, 42, 142...Inner peripheral flow path part, 50, 150...Wall part, 142A, 142B, 142C...Arc part, 150A, 150B, 150C...Arc wall, D1, D2, D3, D4...Width dimension, E1, E2, E3...Radial dimension, J...Central axis, W...Plate-shaped sample, Wa...Outer edge

Claims

1. A plate-shaped electrostatic chuck portion having a mounting surface for placing a plate-shaped sample and having electrostatic adsorption electrodes provided inside, It comprises a disc-shaped base portion centered on a central axis, which supports the electrostatic chuck portion from the opposite side of the mounting surface described above on the support surface, A refrigerant flow path is provided inside the base portion, extending along the support surface. The base portion has a wall portion that divides the refrigerant flow path radially and defines it in a spiral shape with respect to the central axis, The radial dimension of the wall portion decreases as it moves away from the central axis. Electrostatic chuck device.

2. The aforementioned wall portion is continuously spaced apart from the central axis while increasing its radius of curvature along the circumferential direction, and its radial dimension continuously decreases as it moves radially outward. The electrostatic chuck device according to claim 1.

3. The aforementioned wall portion is It has a plurality of arc-shaped walls that extend in an arc shape around the central axis and are arranged concentrically, Of the multiple arc-shaped walls, the arc-shaped wall located radially outward has a smaller radial dimension than the arc-shaped wall located radially inward. The electrostatic chuck device according to claim 1.

4. The wall portion has a first circular arc wall, a second circular arc wall, and a third circular arc wall that extend in an arc shape around the central axis and are arranged concentrically. The first circular arc wall, the second circular arc wall, and the third circular arc wall each have a uniform radial dimension along their entire length. The refrigerant flow path is The first arc portion of the refrigerant flow path, A second arc portion located radially outward from the first arc portion, A third arc portion located radially outward from the second arc portion, The third arc portion has an outer peripheral flow channel located radially outward, The first arc portion, the second arc portion, the third arc portion, and the outer peripheral flow channel portion are arranged concentrically with respect to the central axis and each extends in an arc shape. The first circular arc wall is located radially between the first circular arc portion and the second circular arc portion. The second circular arc wall is located radially between the second circular arc portion and the third circular arc portion. The third circular arc wall is located radially between the third circular arc portion and the outer peripheral flow channel portion. The radial dimension of the second circular arc wall is smaller than the radial dimension of the first circular arc wall. The radial dimension of the third arc wall is smaller than the radial dimension of the second arc wall. The electrostatic chuck device according to claim 1.

5. The first circular arc wall, the second circular arc wall, and the third circular arc wall each extend in an arc shape for more than 3 / 4 of a turn with respect to the central axis. The electrostatic chuck device according to claim 4.

6. The refrigerant flow path is A first connecting portion that connects one end of the first arc portion and one end of the second arc portion by folding them back in a hairpin shape, A second connecting portion that connects the other end of the first arc portion and one end of the third arc portion by folding them back in a hairpin shape, It has a third connecting portion which connects the other end of the second arc portion and one end of the outer peripheral flow channel portion by folding it back in a hairpin shape, The electrostatic chuck device according to claim 4 or 5.

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