Electrostatic chuck and semiconductor manufacturing equipment

Abstract

To provide an electrostatic chuck capable of improving uniformity of cooking gas distribution in a circumferential direction.SOLUTION: An electrostatic chuck comprises a ceramic dielectric substrate and a base plate. The ceramic dielectric substrate includes: first and second principal surfaces, and a groove part recessed from the first principal surface to the second principal surface; and a plurality of cooling gas holes penetrating between the groove part and the second principal surface. The groove part includes first and second circumferential grooves and first and second radial grooves. The plurality of cooling gas holes include first holes overlapping the first radial groove in a planar view and second holes overlapping the second radial groove in the planar view. The base plate includes a gas introduction path in which a cooling gas is supplied to the first holes and the second holes. The first circumferential groove includes a first end positioned at one end in a circumferential direction and a second end positioned at the other end side, and the second circumferential groove includes a third end positioned at one end side in the circumferential direction and a fourth end positioned at the other end side. The third end and the fourth end do not overlap the first end in a radial direction, respectively.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] Aspects of the present invention generally relate to electrostatic chucks and semiconductor manufacturing equipment. [Background technology]

[0002] Electrostatic chucks are used in plasma processing chambers for etching, CVD (Chemical Vapor Deposition), sputtering, ion implantation, ashing, etc. to attract and hold objects to be processed, such as semiconductor wafers and glass substrates. Electrostatic chucks apply electrostatic attraction power to built-in electrodes to attract substrates, such as silicon wafers, by electrostatic force.

[0003] With the recent trend toward miniaturization of semiconductor devices, there is a demand for even greater improvement in the precision of wafer processing, such as etching. It is known that wafer processing precision depends on the wafer temperature during processing. Therefore, in order to improve wafer processing precision, it is necessary to uniformly control the surface temperature of the electrostatic chuck.

[0004] As a means for controlling the surface temperature of an electrostatic chuck, a groove communicating with a cooling gas hole that supplies cooling gas to the surface of the electrostatic chuck (ceramic dielectric substrate) is provided, and the cooling gas is distributed over the surface of the electrostatic chuck through the groove. For example, Patent Document 1 discloses a groove pattern in which a plurality of circumferential grooves extending in the circumferential direction are arranged concentrically and further connected to radial grooves extending in the radial direction, thereby distributing the cooling gas over the surface of the electrostatic chuck.

[0005] However, in the groove pattern of Patent Document 1, each circumferential groove is interrupted midway, and the ends of each circumferential groove are aligned in a straight line in the radial direction. Therefore, with the groove pattern of Patent Document 1, the cooling gas does not reach the area where the ends of each circumferential groove meet, which may reduce the uniformity of the cooling gas distribution in the circumferential direction. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-110883 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made based on the recognition of the above problem, and has an object to provide an electrostatic chuck and a semiconductor manufacturing apparatus that can improve the uniformity of the cooling gas distribution in the circumferential direction. [Means for solving the problem]

[0008] A first invention includes a ceramic dielectric substrate that is circular in a plan view, and a base plate that supports the ceramic dielectric substrate, wherein the ceramic dielectric substrate has a first main surface on which an object to be processed is placed, a second main surface opposite to the first main surface, a groove portion recessed from the first main surface toward the second main surface, and a plurality of cooling gas holes that penetrate between the groove portion and the second main surface and allow a cooling gas to pass through, and the groove portion includes a first circumferential groove that extends in a circumferential direction, a second circumferential groove that extends in the circumferential direction and has at least a portion adjacent to the first circumferential groove in a radial direction, a first radial groove that extends in the radial direction and intersects with the first circumferential groove, and a second circumferential groove that extends in the radial direction and intersects with the second circumferential groove. and second radial grooves intersecting the first radial grooves, the plurality of cooling gas holes having first holes overlapping the first radial grooves in a plan view and second holes overlapping the second radial grooves in a plan view, the base plate having gas inlet passages that supply the cooling gas to the first holes and the second holes, the first circumferential groove having a first end located on one end side in the circumferential direction and a second end located on the other end side in the circumferential direction, the second circumferential groove having a third end located on the one end side in the circumferential direction and a fourth end located on the other end side in the circumferential direction, and the third end and the fourth end do not overlap the first end in the radial direction.

[0009] According to this electrostatic chuck, the third end and the fourth end of the second circumferential groove are arranged so as not to overlap with the first end of the first circumferential groove in the radial direction, thereby preventing the ends of the first circumferential groove and the second circumferential groove from being linearly aligned in the radial direction. This prevents the occurrence of regions where the cooling gas is difficult to reach, improving the uniformity of the cooling gas distribution in the circumferential direction. Furthermore, in recent years, the structure of ceramic dielectric substrates has become more complex in order to improve processing accuracy, and it is sometimes impossible to arrange multiple cooling gas holes on the same circumference. If multiple cooling gas holes are not arranged on the same circumference, depending on the shape of the groove pattern, the uniformity of the cooling gas distribution in the circumferential direction may be reduced. In contrast, according to this electrostatic chuck, the uniformity of the cooling gas distribution in the circumferential direction can be improved even when multiple cooling gas holes are not arranged on the same circumference.

[0010] A second invention provides a ceramic dielectric substrate having a circular shape in a plan view, and a base plate supporting the ceramic dielectric substrate, wherein the ceramic dielectric substrate has a first main surface on which an object to be processed is placed, a second main surface opposite to the first main surface, a groove portion recessed from the first main surface toward the second main surface, and a plurality of cooling gas holes penetrating between the groove portion and the second main surface and provided to allow a cooling gas to pass, the groove portion comprising a first circumferential groove extending in a circumferential direction, a second circumferential groove extending in the circumferential direction and at least a portion of which is adjacent to the first circumferential groove in a radial direction, a first radial groove extending in the radial direction and intersecting the first circumferential groove, and a second circumferential groove extending in the radial direction. and a second radial groove intersecting the first circumferential groove, the plurality of cooling gas holes having a first hole overlapping the first circumferential groove in a plan view and a second hole overlapping the second circumferential groove in a plan view, the base plate having a gas inlet passage for supplying the cooling gas to the first hole and the second hole, the first circumferential groove having a first end located on one end side in the circumferential direction and a second end located on the other end side in the circumferential direction, the second circumferential groove having a third end located on the one end side in the circumferential direction and a fourth end located on the other end side in the circumferential direction, the third end and the fourth end not overlapping the first end in the radial direction.

[0011] According to this electrostatic chuck, the third end and the fourth end of the second circumferential groove are arranged so as not to overlap with the first end of the first circumferential groove in the radial direction, thereby preventing the ends of the first circumferential groove and the second circumferential groove from being aligned linearly in the radial direction. This prevents the occurrence of areas where the cooling gas is difficult to reach, improving the uniformity of the cooling gas distribution in the circumferential direction. Furthermore, according to this electrostatic chuck, even if multiple cooling gas holes are not arranged on the same circumference, the uniformity of the cooling gas distribution in the circumferential direction can be improved.

[0012] A third invention is an electrostatic chuck according to the first or second invention, characterized in that the distance from the intersection of the first radial groove and the first circumferential groove to the first hole is equal to the distance from the intersection of the second radial groove and the second circumferential groove to the second hole.

[0013] According to this electrostatic chuck, by making the distance from the intersection of the first radial groove and the first circumferential groove to the first hole equal to the distance from the intersection of the second radial groove and the second circumferential groove to the second hole, the uniformity of the cooling gas distribution in the circumferential direction can be improved even if the first hole and the second hole are not arranged on the same circumference.

[0014] A fourth invention is an electrostatic chuck according to any one of the first to third inventions, characterized in that the third end and the fourth end do not overlap with the second end in the radial direction.

[0015] According to this electrostatic chuck, the third end and the fourth end of the second circumferential groove are arranged so as not to overlap with the second end of the first circumferential groove in the radial direction, thereby preventing the end of the first circumferential groove and the end of the second circumferential groove from being aligned linearly in the radial direction, thereby further preventing the occurrence of an area where the cooling gas is difficult to reach, and further improving the uniformity of the cooling gas distribution in the circumferential direction.

[0016] A fifth invention is an electrostatic chuck according to any one of the first to fourth inventions, characterized in that the first circumferential groove has a central region including the center in the circumferential direction, and the third end overlaps with the central region in the radial direction.

[0017] According to this electrostatic chuck, the third end of the second circumferential groove is disposed so as to overlap the central region of the first circumferential groove in the radial direction, thereby further improving the uniformity of the cooling gas distribution in the circumferential direction.

[0018] A sixth invention is an electrostatic chuck according to the fifth invention, characterized in that the third end is located closer to the other end in the circumferential direction than the center in the circumferential direction of the first circumferential groove.

[0019] According to this electrostatic chuck, the third end of the second circumferential groove is located closer to the other end in the circumferential direction than the center in the circumferential direction of the first circumferential groove, thereby further improving the uniformity of the cooling gas distribution in the circumferential direction.

[0020] A seventh invention is the electrostatic chuck according to the sixth invention, characterized in that the fourth end is located closer to the other end in the circumferential direction than the second end.

[0021] According to this electrostatic chuck, the fourth end of the second circumferential groove is located closer to the other end in the circumferential direction than the second end of the first circumferential groove, thereby further improving the uniformity of the cooling gas distribution in the circumferential direction.

[0022] An eighth invention is an electrostatic chuck according to any one of the first to seventh inventions, further comprising a heater for heating the ceramic dielectric substrate.

[0023] This electrostatic chuck can improve the uniformity of the cooling gas distribution in the circumferential direction even when a heater is provided.

[0024] A ninth invention is a semiconductor manufacturing apparatus comprising an electrostatic chuck according to any one of the first to eighth inventions, and a gas supply unit that supplies the cooling gas to the first hole and the second hole via the gas introduction path.

[0025] According to this semiconductor manufacturing apparatus, the surface temperature of the electrostatic chuck can be controlled more uniformly, and the precision of wafer processing such as etching can be improved. [Effects of the Invention]

[0026] According to aspects of the present invention, an electrostatic chuck and a semiconductor manufacturing apparatus are provided that can improve the uniformity of the cooling gas distribution in the circumferential direction. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a cross-sectional view schematically illustrating an electrostatic chuck according to a first embodiment. [Figure 2] 1 is a plan view schematically illustrating a ceramic dielectric substrate according to a first embodiment. [Figure 3] 1 is a plan view schematically illustrating a portion of a ceramic dielectric substrate according to a first embodiment. [Figure 4] FIG. 4 is a plan view schematically illustrating a portion of a ceramic dielectric substrate according to a modified example of the first embodiment. [Figure 5] FIG. 4 is a plan view schematically showing a ceramic dielectric substrate according to a second embodiment. [Figure 6] FIG. 4 is a plan view schematically illustrating a portion of a ceramic dielectric substrate according to a second embodiment. [Figure 7] FIG. 10 is a plan view schematically illustrating a portion of a ceramic dielectric substrate according to a modified example of the second embodiment. [Figure 8] FIG. 10 is a plan view schematically showing a ceramic dielectric substrate according to a third embodiment. [Figure 9] FIG. 11 is a plan view schematically showing a ceramic dielectric substrate according to a modified example of the third embodiment. [Figure 10]FIG. 10 is a plan view schematically showing a ceramic dielectric substrate according to a fourth embodiment. [Figure 11] FIG. 10 is a plan view schematically showing a ceramic dielectric substrate according to a fourth embodiment. [Figure 12] 1 is a cross-sectional view schematically illustrating a wafer processing apparatus including an electrostatic chuck according to a first embodiment. [Figure 13] 1 is a cross-sectional view schematically illustrating a wafer processing apparatus including an electrostatic chuck according to a first embodiment. [Figure 14] FIG. 10 is a cross-sectional view schematically showing a wafer processing apparatus including an electrostatic chuck according to a modified example of the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, like components are designated by like reference numerals and detailed descriptions thereof will be omitted where appropriate.

[0029] FIG. 1 is a cross-sectional view schematically illustrating an electrostatic chuck according to a first embodiment. As shown in FIG. 1, the electrostatic chuck 100 according to the first embodiment includes a ceramic dielectric substrate 10, a base plate 20, and a heater 30.

[0030] The ceramic dielectric substrate 10 is, for example, a flat base material made of a polycrystalline ceramic sintered body. Examples of crystalline materials contained in the ceramic dielectric substrate 10 include Al2O3, Y2O3, and YAG. By using such materials, the infrared transmittance, insulation resistance, and plasma durability of the ceramic dielectric substrate 10 can be improved.

[0031] The ceramic dielectric substrate 10 has a first main surface 11, a second main surface 12, a groove 13, and a plurality of cooling gas holes 14. The first main surface 11 is exposed to the outside and is the surface on which a processing object W, such as a semiconductor wafer, is placed. The second main surface 12 is the surface opposite the first main surface 11. The groove 13 is a recess that recesses from the first main surface 11 toward the second main surface 12. The plurality of cooling gas holes 14 penetrate between the groove 13 and the second main surface 12. The plurality of cooling gas holes 14 are provided to allow cooling gas to pass through. The plurality of cooling gas holes 14 communicate with the groove 13. As a result, the groove 13 diffuses the cooling gas supplied from the plurality of cooling gas holes 14 to the first main surface 11. The groove 13 and the plurality of cooling gas holes 14 will be described later.

[0032] In this specification, the direction perpendicular to the first main surface 11 is referred to as the Z direction. In other words, the Z direction is the direction connecting the first main surface 11 and the second main surface 12. One of the directions perpendicular to the Z direction is referred to as the X direction, and the direction perpendicular to the Z direction and the X direction is referred to as the Y direction. In this specification, "in-plane" refers to, for example, the XY plane. In this specification, "planar view" refers to a state viewed along the Z direction.

[0033] The first main surface 11 has, for example, a flat portion 11a and protruding portions 11b. The flat portion 11a is, for example, a surface parallel to the second main surface 12. The protruding portions 11b protrude from the flat portion 11a toward the side opposite the second main surface 12. The processing object W is placed on and supported by the protruding portions 11b. The protruding portions 11b contact the back surface of the processing object W. By providing the protruding portions 11b, a space can be formed between the back surface of the processing object W placed on the electrostatic chuck 100 and the flat portion 11a. By appropriately selecting the height, number, area ratio, shape, etc. of the protruding portions 11b, it is possible to, for example, make particles adhering to the processing object W in a preferable state.

[0034] An electrode layer 15 is provided inside the ceramic dielectric substrate 10. The electrode layer 15 is interposed between the first main surface 11 and the second main surface 12. That is, the electrode layer 15 is formed so as to be inserted into the ceramic dielectric substrate 10. The electrode layer 15 is integrally sintered with the ceramic dielectric substrate 10. Note that the electrode layer 15 is not limited to being interposed between the first main surface 11 and the second main surface 12, and may be provided on the second main surface 12.

[0035] The electrode layer 15 is provided with a connection portion 16 extending toward the second main surface 12 of the ceramic dielectric substrate 10. The connection portion 16 is a via (solid type) or a via hole (hollow type) that is electrically connected to the electrode layer 15, or a metal terminal that is connected by an appropriate method such as brazing.

[0036] The electrostatic chuck 100 generates an electric charge on the first main surface 11 side of the electrode layer 15 by applying a voltage (adsorption voltage) from the adsorption power source 505 to the electrode layer 15, and adsorbs and holds the workpiece W by electrostatic force.

[0037] The electrode layer 15 is provided along the first main surface 11 and the second main surface 12. The electrode layer 15 is an adsorption electrode for adsorbing and holding the processing target W. The electrode layer 15 may be a monopolar or bipolar type. The electrode layer 15 may also be a tripolar or other multipolar type. The number of electrode layers 15 and the arrangement of the electrode layers 15 are selected appropriately.

[0038] The base plate 20 is provided on the second main surface 12 side of the ceramic dielectric substrate 10, and supports the ceramic dielectric substrate 10. The base plate 20 is made of a metal such as aluminum.

[0039] The base plate 20 is divided into, for example, an upper portion 20a and a lower portion 20b. A communication passage 25 is provided between the upper portion 20a and the lower portion 20b. One end of the communication passage 25 is connected to the input passage 21, and the other end is connected to the output passage 22.

[0040] The base plate 20 also serves to adjust the temperature of the electrostatic chuck 100. For example, when cooling the electrostatic chuck 100, a cooling medium such as helium gas flows in through the input path 21, passes through the connecting path 25, and flows out through the output path 22. This allows the cooling medium to absorb heat from the base plate 20 and cool the ceramic dielectric substrate 10 attached thereto. On the other hand, when keeping the electrostatic chuck 100 warm, a heat-retaining medium can also be placed in the connecting path 25.

[0041] The base plate 20 is also provided with at least one gas inlet path 23. In this example, the base plate 20 is provided with a plurality of gas inlet paths 23. Each gas inlet path 23 is provided, for example, so as to penetrate the base plate 20 in the Z direction. The plurality of gas inlet paths 23 are respectively connected to the plurality of cooling gas holes 14 of the ceramic dielectric substrate 10. As a result, the cooling gas introduced from the gas inlet paths 23 of the base plate 20 passes through the cooling gas holes 14 of the ceramic dielectric substrate 10 and is diffused to the first main surface 11 along the grooves 13 connected to the cooling gas holes 14. The gas inlet paths 23 may be branched inside the base plate 20, as will be described later (see FIG. 14).

[0042] Cooling gas is supplied to the cooling gas holes 14 from a gas supply unit 24 (see FIGS. 13 and 14). The gas supply unit 24 is connected to a gas introduction path 23 and supplies cooling gas to the cooling gas holes 14 via the gas introduction path 23. The gas supply unit 24 controls, for example, the pressure of the cooling gas to be supplied and the start and stop of the supply of cooling gas.

[0043] In this example, multiple gas introduction paths 23 are connected to one gas supply unit 24. That is, in this example, cooling gas is supplied to multiple cooling gas holes 14 from one gas supply unit 24 via multiple gas introduction paths 23. In other words, in this example, multiple cooling gas holes 14 are controlled by one gas supply unit 24. The pressure of the cooling gas supplied to each cooling gas hole 14 is, for example, the same.

[0044] In the embodiment, one gas inlet path 23 may be connected (communicated) with a plurality of cooling gas holes 14. In this case, the plurality of cooling gas holes 14 connected to this one gas inlet path 23 are also controlled by one gas supply unit 24.

[0045] In this example, a first porous portion 41 and a second porous portion 42 are provided at the connection between the gas introduction path 23 and the cooling gas hole 14. The first porous portion 41 is provided inside the cooling gas hole 14. The second porous portion 42 is provided inside the gas introduction path 23. The first porous portion 41 and the second porous portion 42 face each other in the Z direction.

[0046] The material of the first porous portion 41 and the second porous portion 42 can be, for example, insulating ceramics. The first porous portion 41 and the second porous portion 42 contain, for example, at least one of aluminum oxide (Al2O3), titanium oxide (TiO2), and yttrium oxide (Y2O3). Note that the first porous portion 41 and the second porous portion 42 are provided as needed and can be omitted.

[0047] The heater 30 heats the ceramic dielectric substrate 10. The heater 30 heats the ceramic dielectric substrate 10, thereby heating the processing object W via the ceramic dielectric substrate 10. In this example, the heater 30 is separate from the ceramic dielectric substrate 10 and is provided between the ceramic dielectric substrate 10 and the base plate 20. The heater 30 is bonded to the base plate 20 via, for example, an adhesive layer. The heater 30 is bonded to the ceramic dielectric substrate 10 via, for example, an adhesive layer.

[0048] The heater 30 may be formed so as to be inserted into the ceramic dielectric substrate 10. In other words, the heater 30 may be built into the ceramic dielectric substrate 10. The heater 30 is provided as needed and may be omitted.

[0049] FIG. 2 is a plan view schematically illustrating the ceramic dielectric substrate according to the first embodiment. FIG. 3 is a plan view schematically illustrating a portion of the ceramic dielectric substrate according to the first embodiment. 2 and 3 are plan views of the ceramic dielectric substrate 10 as viewed from the first main surface 11 side. FIG. 3 is an enlarged view of the region R1 shown in FIG. As shown in FIGS. 2 and 3, the ceramic dielectric substrate 10 has a circular shape in a plan view.

[0050] Grooves 13 are provided on the first main surface 11 side of the ceramic dielectric substrate 10. The grooves 13 include circumferential grooves 60 and radial grooves 70. The circumferential grooves 60 include multiple circumferential grooves extending in the circumferential direction Dc and aligned in the radial direction Dr. The radial grooves 70 include multiple radial grooves extending in the radial direction Dr and aligned in the circumferential direction Dc. At least some of the multiple radial grooves intersect with at least some of the multiple circumferential grooves. The circumferential direction Dc is a direction along the circumference of a circle centered at the center CT of the ceramic dielectric substrate 10. The radial direction Dr is a direction from the center CT of the ceramic dielectric substrate 10 toward the outer edge 10a of the ceramic dielectric substrate 10.

[0051] In this example, the circumferential groove portion 60 has a plurality of circumferential grooves 60a to 60e aligned in the radial direction Dr. The circumferential grooves 60a to 60e are aligned in the radial direction Dr from the outermost periphery toward the center CT in the following order: circumferential groove 60a, circumferential groove 60b, circumferential groove 60c, circumferential groove 60d, and circumferential groove 60e. The circumferential grooves 60a to 60e are provided on the circumferences of concentric circles having different radii centered at the center CT. The circumferential grooves 60a to 60e are provided at equal intervals in the radial direction Dr. Of these circumferential grooves 60a to 60e, two adjacent to each other in the radial direction Dr are referred to as a first circumferential groove 61 and a second circumferential groove 62.

[0052] In the following description, the circumferential groove 60b will be referred to as the first circumferential groove 61, and the circumferential groove 60c, which is located more inward in the radial direction Dr than the first circumferential groove 61 and adjacent to the first circumferential groove 61, will be referred to as the second circumferential groove 62. However, the first circumferential groove 61 and the second circumferential groove 62 are not limited to these. The first circumferential groove 61 and the second circumferential groove 62 may be any two circumferential grooves adjacent to each other in the radial direction Dr. That is, for example, the circumferential groove 60c may be the first circumferential groove 61, and the circumferential groove 60d may be the second circumferential groove 62. Furthermore, the second circumferential groove 62 may be a circumferential groove located more outward in the radial direction Dr than the first circumferential groove 61 and adjacent to the first circumferential groove 61. That is, for example, the circumferential groove 60c may be the first circumferential groove 61, and the circumferential groove 60b may be the second circumferential groove 62.

[0053] At least a portion of the second circumferential groove 62 overlaps with the first circumferential groove 61 in the radial direction Dr. The entire second circumferential groove 62 may overlap with the first circumferential groove 61 in the radial direction Dr, or only a portion of the second circumferential groove 62 may overlap with the first circumferential groove 61 in the radial direction Dr. In other words, a portion of the second circumferential groove 62 does not have to overlap with the first circumferential groove 61 in the radial direction Dr. In this example, only a portion of the second circumferential groove 62 overlaps with the first circumferential groove 61 in the radial direction Dr.

[0054] The number of circumferential grooves aligned in the radial direction Dr is not limited to 5, but may be equal to or greater than 2. The intervals between the circumferential grooves aligned in the radial direction Dr do not have to be equal.

[0055] In this example, a plurality of circumferential grooves on each periphery are provided discontinuously on the same circumference. More specifically, two circumferential grooves 60a are provided discontinuously on the same circumference. The lengths of the circumferential grooves 60a provided on the same circumference in the circumferential direction Dc are the same. Five circumferential grooves 60b are provided discontinuously on the same circumference. The lengths of the circumferential grooves 60b provided on the same circumference in the circumferential direction Dc are the same. Five circumferential grooves 60c are provided discontinuously on the same circumference. The lengths of the circumferential grooves 60c provided on the same circumference in the circumferential direction Dc are the same. Five circumferential grooves 60d are provided discontinuously on the same circumference. The lengths of the circumferential grooves 60d provided on the same circumference in the circumferential direction Dc are the same. Ten circumferential grooves 60e are provided discontinuously on the same circumference. The circumferential grooves 60e provided on the same circumference have the same length in the circumferential direction Dc. The number of circumferential grooves provided on the same circumference is preferably, for example, two or more.

[0056] In this example, the radial groove portion 70 has a plurality of radial grooves 70a to 70j aligned in the circumferential direction Dc. The radial grooves 70a to 70j are aligned clockwise in the circumferential direction Dc in the following order: radial groove 70a, radial groove 70b, radial groove 70c, radial groove 70d, radial groove 70e, radial groove 70f, radial groove 70g, radial groove 70h, radial groove 70i, and radial groove 70j. The radial grooves 70a to 70j are provided at equal intervals in the circumferential direction Dc. Of these radial grooves 70a to 70j, one that intersects with the first circumferential groove 61 is referred to as the first radial groove 71, and one that intersects with the second circumferential groove 62 is referred to as the second radial groove 72. The intersection of the first radial groove 71 and the first circumferential groove 61 is referred to as intersection P1, and the intersection of the second radial groove 72 and the second circumferential groove 62 is referred to as intersection P2. The first radial groove 71 and the second radial groove 72 are adjacent to each other in the circumferential direction Dc, for example. In this example, the radial groove 70a is the first radial groove 71, and the radial groove 70j is the second radial groove 72.

[0057] It is preferable that at least a portion of the second radial grooves 72 overlap with the first radial grooves 71 in the circumferential direction Dc. In this example, all of the radial grooves 70a to 70j extend from the circumferential groove 60a to the circumferential groove 60e. That is, in this example, all of the second radial grooves 72 overlap with the first radial grooves 71 in the circumferential direction Dc.

[0058] The number of radial grooves aligned in the circumferential direction Dc is not limited to 10, but may be 2 or more. The number of radial grooves aligned in the circumferential direction Dc is equal to the sum of the number of first circumferential grooves 61 provided on the same circumference and the number of second circumferential grooves 62 provided on the same circumference, for example. The intervals between the radial grooves aligned in the circumferential direction Dc do not have to be equal.

[0059] As shown in FIG. 3, the first circumferential groove 61 has a first end 61a and a second end 61b. The first end 61a is located at one end of the first circumferential groove 61 in the circumferential direction Dc. The second end 61b is located at the other end of the first circumferential groove 61 in the circumferential direction Dc. The second circumferential groove 62 has a third end 62a and a fourth end 62b. The third end 62a is located at one end of the second circumferential groove 62 in the circumferential direction Dc. The fourth end 62b is located at the other end of the second circumferential groove 62 in the circumferential direction Dc. Note that in this example, the clockwise end is referred to as the one end and the counterclockwise end is referred to as the other end, but the one end and the other end may be reversed.

[0060] The third end 62a of the second circumferential groove 62 does not overlap with the first end 61a of the first circumferential groove 61 in the radial direction Dr. That is, an imaginary line IL3 connecting the third end 62a and the center CT intersects with an imaginary line IL1 connecting the first end 61a and the center CT. Furthermore, the fourth end 62b of the second circumferential groove 62 does not overlap with the first end 61a of the first circumferential groove 61 in the radial direction Dr. That is, an imaginary line IL4 connecting the fourth end 62b and the center CT intersects with the imaginary line IL1.

[0061] By arranging the third end 62a and the fourth end 62b of the second circumferential groove 62 so as not to overlap the first end 61a of the first circumferential groove 61 in the radial direction Dr, it is possible to prevent the end of the first circumferential groove 61 and the end of the second circumferential groove 62 from being aligned in a straight line in the radial direction Dr. This makes it possible to prevent the occurrence of an area where the cooling gas is difficult to reach, and improves the uniformity of the cooling gas distribution in the circumferential direction Dc.

[0062] Furthermore, in recent years, the structure of the ceramic dielectric substrate 10 has become more complex in order to improve processing accuracy, and it may not be possible to arrange multiple cooling gas holes 14 on the same circumference. For example, if a heater 30 is provided in the ceramic dielectric substrate 10, multiple cooling gas holes 14 may be provided to avoid the heater 30, which may result in multiple cooling gas holes 14 not being arranged on the same circumference. If multiple cooling gas holes 14 are not arranged on the same circumference, the uniformity of the cooling gas distribution in the circumferential direction Dc may be reduced depending on the shape of the groove pattern. In contrast, with this electrostatic chuck 100, the uniformity of the cooling gas distribution in the circumferential direction Dc can be improved even when multiple cooling gas holes 14 are not arranged on the same circumference. For example, the uniformity of the cooling gas distribution in the circumferential direction Dc can be improved even in an electrostatic chuck 100 provided with a heater 30.

[0063] Furthermore, in this example, the third end 62a of the second circumferential groove 62 does not overlap with the second end 61b of the first circumferential groove 61 in the radial direction Dr. That is, in this example, the imaginary line IL3 intersects with the imaginary line IL2 connecting the second end 61b and the center CT. Also, in this example, the fourth end 62b of the second circumferential groove 62 does not overlap with the second end 61b of the first circumferential groove 61 in the radial direction Dr. That is, in this example, the imaginary line IL4 intersects with the imaginary line IL2.

[0064] By arranging the third end 62a and the fourth end 62b of the second circumferential groove 62 so as not to overlap the second end 61b of the first circumferential groove 61 in the radial direction Dr, it is possible to prevent the end of the first circumferential groove 61 and the end of the second circumferential groove 62 from being aligned in a straight line in the radial direction Dr. This further prevents the occurrence of an area where the cooling gas is difficult to reach, and further improves the uniformity of the cooling gas distribution in the circumferential direction Dc.

[0065] The third end 62a may overlap the second end 61b in the radial direction Dr. That is, the imaginary line IL3 may be located on the same line as the imaginary line IL2. The fourth end 62b may overlap the second end 61b in the radial direction Dr. That is, the imaginary line IL4 may be located on the same line as the imaginary line IL2.

[0066] In this example, the multiple cooling gas holes 14 are provided at positions that overlap with the radial grooves 70a to 70j in a plan view. The multiple cooling gas holes 14 include a first hole 14a that overlaps with the first radial groove 71 in a plan view and a second hole 14b that overlaps with the second radial groove 72 in a plan view. The first hole 14a communicates with the first radial groove 71. The second hole 14b communicates with the second radial groove 72. In this example, the multiple cooling gas holes 14, including the first hole 14a and the second hole 14b, are arranged on the same circumference about a center CT.

[0067] The first hole 14a and the second hole 14b are connected to one gas introduction path 23. That is, the first hole 14a and the second hole 14b are connected to the same gas introduction path 23. In other words, the first hole 14a and the second hole 14b are connected to one gas supply unit 24. In other words, the first hole 14a and the second hole 14b are controlled by one gas supply unit 24. The pressure of the cooling gas supplied to the first hole 14a is, for example, the same as the pressure of the cooling gas supplied to the second hole 14b. In this example, all of the cooling gas holes 14, including the first hole 14a and the second hole 14b, are connected to one gas supply unit 24.

[0068] Furthermore, a distance D1 from an intersection P1 between the first radial groove 71 and the first circumferential groove 61 to the first hole 14a is equal to a distance D2 from an intersection P2 between the second radial groove 72 and the second circumferential groove 62 to the second hole 14b. By making the distance D1 equal to the distance D2, it is possible to improve the uniformity of the cooling gas distribution in the circumferential direction Dc even when the first hole 14a and the second hole 14b are not arranged on the same circumference.

[0069] Note that distance D1 and distance D2 may be different from each other. Furthermore, distance D1 and distance D2 may both be 0. That is, first hole 14a may be provided at a position overlapping intersection P1, and second hole 14b may be provided at a position overlapping intersection P2. Such an example will be described with reference to FIGS. 8 and 9.

[0070] Furthermore, at least a portion of the second circumferential groove 62 overlaps with the first circumferential groove 61 in the radial direction Dr. That is, at least one of the third end 62a and the fourth end 62b of the second circumferential groove 62 overlaps with the first circumferential groove 61 in the radial direction Dr. In this example, the third end 62a of the second circumferential groove 62 overlaps with the first circumferential groove 61 in the radial direction Dr, and the fourth end 62b of the second circumferential groove 62 does not overlap with the first circumferential groove 61 in the radial direction Dr. That is, a portion of the second circumferential groove 62 overlaps with the first circumferential groove 61 in the radial direction Dr, and another portion of the second circumferential groove 62 does not overlap with the first circumferential groove 61 in the radial direction Dr. In other words, the second circumferential groove 62 is disposed so as to be offset from the first circumferential groove 61 in the radial direction Dr.

[0071] The first circumferential groove 61 has a central region 61c, a first end region 61d, and a second end region 61e. The first end region 61d is located on one end side in the circumferential direction Dc and includes the first end portion 61a. The second end region 61e is located on the other end side in the circumferential direction Dc and includes the second end portion 61b. The central region 61c is located between the first end region 61d and the second end region 61e in the circumferential direction Dc. The central region 61c includes the center of the first circumferential groove 61 in the circumferential direction Dc. In FIG. 3, a center line CL that passes through the center of the first circumferential groove 61 in the circumferential direction Dc and extends in the radial direction Dr is represented by a dashed dotted line. In this example, the center of the first circumferential groove 61 in the circumferential direction Dc coincides with the intersection point P1. For example, if the first circumferential groove 61 is divided equally into three regions in the circumferential direction Dc, the region located closest to one end can be considered as the first end region 61d, the region located closest to the other end can be considered as the second end region 61e, and the region located in the center can be considered as the central region 61c.

[0072] For example, the third end 62a of the second circumferential groove 62 overlaps with the central region 61c of the first circumferential groove 61 in the radial direction Dr. By arranging the third end 62a of the second circumferential groove 62 so as to overlap with the central region 61c of the first circumferential groove 61 in the radial direction Dr, the uniformity of the cooling gas distribution in the circumferential direction Dc can be further improved.

[0073] In this case, the third end 62a of the second circumferential groove 62 is preferably located closer to the other end in the circumferential direction Dc than the center (center line CL) of the first circumferential groove 61 in the circumferential direction Dc. In other words, the second circumferential groove 62 does not preferably overlap with the center line CL in a plan view. By having the third end 62a of the second circumferential groove 62 located closer to the other end in the circumferential direction Dc than the center (center line CL) of the first circumferential groove 61 in the circumferential direction Dc, the uniformity of the cooling gas distribution in the circumferential direction Dc can be further improved.

[0074] In this case, the fourth end 62b of the second circumferential groove 62 is preferably located closer to the other end in the circumferential direction Dc than the second end 61b of the first circumferential groove 61. In other words, the fourth end 62b of the second circumferential groove 62 does not preferably overlap with the first circumferential groove 61 in the radial direction Dr. By having the fourth end 62b of the second circumferential groove 62 located closer to the other end in the circumferential direction Dc than the second end 61b of the first circumferential groove 61, the uniformity of the cooling gas distribution in the circumferential direction Dc can be further improved.

[0075] The third end 62a of the second circumferential groove 62 may overlap with the first end region 61d of the first circumferential groove 61 in the radial direction Dr, or may overlap with the second end region 61e of the first circumferential groove 61. The third end 62a of the second circumferential groove 62 may be located closer to one end in the circumferential direction Dc than the center (center line CL) of the first circumferential groove 61 in the circumferential direction Dc. That is, the second circumferential groove 62 may overlap with the center line CL in a plan view. The fourth end 62b of the second circumferential groove 62 may be located closer to one end in the circumferential direction Dc than the second end 61b of the first circumferential groove 61. That is, the fourth end 62b of the second circumferential groove 62 may overlap with the first circumferential groove 61 in the radial direction Dr.

[0076] In this example, an end portion of the circumferential groove 60d on one end side in the circumferential direction Dc overlaps with an end portion (first end portion 61a) of the circumferential groove 60b (first circumferential groove 61) on one end side in the circumferential direction Dc in the radial direction Dr. An end portion of the circumferential groove 60d on the other end side in the circumferential direction Dc overlaps with an end portion (second end portion 61b) of the circumferential groove 60b (first circumferential groove 61) on the other end side in the circumferential direction Dc in the radial direction Dr. In this way, when another circumferential groove is disposed between two circumferential grooves (i.e., when the two circumferential grooves are not adjacent to each other), the ends of the two circumferential grooves may overlap with each other in the radial direction Dr.

[0077] FIG. 4 is a plan view schematically illustrating a portion of a ceramic dielectric substrate according to a modified example of the first embodiment. FIG. 4 is a plan view of the ceramic dielectric substrate 10A as viewed from the first main surface 11 side. FIG. 4 is an enlarged view of a region corresponding to region R1 shown in FIG. As shown in Fig. 4, in this example, the first holes 14a and the second holes 14b are not arranged on the same circumference. Except for this, the ceramic dielectric substrate 10 according to the first embodiment is the same as that shown in Figs. 2 and 3.

[0078] In this example, the third end 62a and the fourth end 62b of the second circumferential groove 62 are positioned so as not to overlap with the first end 61a and the second end 61b of the first circumferential groove 61 in the radial direction Dr, thereby improving the uniformity of the cooling gas distribution in the circumferential direction Dc.

[0079] Also in this example, the distance D1 from the intersection P1 between the first radial groove 71 and the first circumferential groove 61 to the first hole 14a is equal to the distance D2 from the intersection P2 between the second radial groove 72 and the second circumferential groove 62 to the second hole 14b. By making the distance D1 equal to the distance D2, the uniformity of the cooling gas distribution in the circumferential direction Dc can be improved even if the first holes 14a and the second holes 14b are not arranged on the same circumference.

[0080] FIG. 5 is a plan view schematically illustrating a ceramic dielectric substrate according to the second embodiment. FIG. 6 is a plan view schematically illustrating a portion of the ceramic dielectric substrate according to the second embodiment. 5 and 6 are plan views of the ceramic dielectric substrate 10B as viewed from the first main surface 11 side. FIG. 5 is an enlarged view of the region R2 shown in FIG. 5 and 6, in this example, the multiple cooling gas holes 14 are provided at positions overlapping with the circumferential grooves 60a, 60b in a plan view. The multiple cooling gas holes 14 include a first hole 14a that overlaps with the first circumferential groove 61 in a plan view and a second hole 14b that overlaps with the second circumferential groove 62 in a plan view. The first hole 14a communicates with the first circumferential groove 61. The second hole 14b communicates with the second circumferential groove 62. Other than that, the ceramic dielectric substrate 10 according to the first embodiment is the same as that shown in FIGS. 2 and 3.

[0081] In this example as well, the third end 62a of the second circumferential groove 62 does not overlap with the first end 61a of the first circumferential groove 61 in the radial direction Dr. Moreover, the fourth end 62b of the second circumferential groove 62 does not overlap with the first end 61a of the first circumferential groove 61 in the radial direction Dr. Moreover, the third end 62a of the second circumferential groove 62 does not overlap with the second end 61b of the first circumferential groove 61 in the radial direction Dr. Moreover, the fourth end 62b of the second circumferential groove 62 does not overlap with the second end 61b of the first circumferential groove 61 in the radial direction Dr.

[0082] By arranging the third end 62a and the fourth end 62b of the second circumferential groove 62 so as not to overlap the first end 61a and the second end 61b of the first circumferential groove 61 in the radial direction Dr, the end of the first circumferential groove 61 and the end of the second circumferential groove 62 can be prevented from being aligned in a straight line in the radial direction Dr. This prevents the occurrence of an area where the cooling gas is difficult to reach, and improves the uniformity of the cooling gas distribution in the circumferential direction Dc. Furthermore, even if the cooling gas holes 14 are not arranged on the same circumference, the uniformity of the cooling gas distribution in the circumferential direction Dc can be improved.

[0083] Also in this example, the distance D1 from the intersection P1 between the first radial groove 71 and the first circumferential groove 61 to the first hole 14a is equal to the distance D2 from the intersection P2 between the second radial groove 72 and the second circumferential groove 62 to the second hole 14b. By making the distance D1 equal to the distance D2, the uniformity of the cooling gas distribution in the circumferential direction Dc can be improved even if the first holes 14a and the second holes 14b are not arranged on the same circumference.

[0084] FIG. 7 is a plan view schematically illustrating a portion of a ceramic dielectric substrate according to a modified example of the second embodiment. FIG. 7 is a plan view of the ceramic dielectric substrate 10C as viewed from the first main surface 11 side. FIG. 7 is an enlarged view of a region corresponding to region R2 shown in FIG. 7, in this example, the first holes 14a and the second holes 14b are provided at positions that overlap in the radial direction Dr. Other than that, the ceramic dielectric substrate 10B according to the second embodiment is the same as that shown in FIGS.

[0085] In this example, the third end 62a and the fourth end 62b of the second circumferential groove 62 are positioned so as not to overlap with the first end 61a and the second end 61b of the first circumferential groove 61 in the radial direction Dr, thereby improving the uniformity of the cooling gas distribution in the circumferential direction Dc.

[0086] Also in this example, the distance D1 from the intersection P1 between the first radial groove 71 and the first circumferential groove 61 to the first hole 14a is equal to the distance D2 from the intersection P2 between the second radial groove 72 and the second circumferential groove 62 to the second hole 14b. By making the distance D1 equal to the distance D2, it is possible to improve the uniformity of the cooling gas distribution in the circumferential direction Dc even when the first hole 14a and the second hole 14b are provided at positions that overlap in the radial direction Dr.

[0087] FIG. 8 is a plan view schematically showing a ceramic dielectric substrate according to a third embodiment. FIG. 8 is a plan view of the ceramic dielectric substrate 10D as viewed from the first main surface 11 side. 8, in this example, the first holes 14a are provided at positions overlapping with the intersection point P1, and the second holes 14b are provided at positions overlapping with the intersection point P2. Other than that, the ceramic dielectric substrate 10 according to the first embodiment is the same as that shown in FIGS. 2 and 3.

[0088] In this example, the third end 62a and the fourth end 62b of the second circumferential groove 62 are positioned so as not to overlap with the first end 61a and the second end 61b of the first circumferential groove 61 in the radial direction Dr, thereby improving the uniformity of the cooling gas distribution in the circumferential direction Dc.

[0089] In this way, the cooling gas holes 14 may be provided at a position overlapping with the circumferential grooves (first circumferential groove 61 and second circumferential groove 62), or may be provided at a position overlapping with the radial grooves (first radial groove 71 and second radial groove 72), or may be provided at a position overlapping with the intersection of the circumferential groove and the radial groove (intersection P1 and intersection P2).

[0090] FIG. 9 is a plan view schematically illustrating a ceramic dielectric substrate according to a modified example of the third embodiment. FIG. 9 is a plan view of the ceramic dielectric substrate 10E as viewed from the first main surface 11 side. 9, in this example, in addition to the cooling gas holes 14 provided in the ceramic dielectric substrate 10D according to the third embodiment shown in FIG. 8, cooling gas holes 14 are also provided at positions overlapping with some of the other intersections between the circumferential grooves and the radial grooves. The cooling gas holes 14 provided at the positions overlapping with these other intersections are provided as needed and can be omitted.

[0091] In this example, the third end 62a and the fourth end 62b of the second circumferential groove 62 are positioned so as not to overlap with the first end 61a and the second end 61b of the first circumferential groove 61 in the radial direction Dr, thereby improving the uniformity of the cooling gas distribution in the circumferential direction Dc.

[0092] 10 and 11 are plan views schematically showing the ceramic dielectric substrate according to the fourth embodiment. 10 and 11 are plan views of the ceramic dielectric substrate 10F as viewed from the first main surface 11 side. 10 and 11, in this example, the ceramic dielectric substrate 10F has a first zone 210 and a second zone 220. Other than that, it is the same as the ceramic dielectric substrate 10A according to the modified example of the first embodiment shown in FIG.

[0093] In this example, the first zone 210 and the second zone 220 are aligned in the radial direction Dr. The second zone 220 is located inside the first zone 210 in the radial direction Dr. In this example, the first zone 210 is located outside the two-dot chain line, and the second zone 220 is located inside the two-dot chain line. The first zone 210 includes, for example, the outer edge 10a. The second zone 220 includes, for example, the center CT.

[0094] 10, the first zone 210 and the second zone 220 each have grooves 13 (circumferential grooves 60 and radial grooves 70) and a plurality of cooling gas holes 14. The grooves 13 of the first zone 210 and the grooves 13 of the second zone 220 do not communicate with each other.

[0095] The first zone 210 has a first hole 14a that overlaps with the first radial groove 71 in a plan view and a second hole 14b that overlaps with the second radial groove 72 in a plan view. In this example, the first hole 14a and the second hole 14b are not arranged on the same circumference. The first hole 14a and the second hole 14b may be arranged on the same circumference. Furthermore, the first hole 14a and the second hole 14b may be arranged at a position that overlaps with the circumferential groove portion 60 in a plan view, or at a position that overlaps with an intersection of the circumferential groove portion 60 and the radial groove portion 70.

[0096] In this example, the circumferential groove portion 60 has circumferential grooves 60a to 60e provided in the first zone 210, as well as circumferential grooves 60f to 60h provided in the second zone 220. The circumferential grooves 60f to 60h are arranged in the radial direction Dr from the outer periphery toward the center CT in the order of circumferential groove 60f, circumferential groove 60g, and circumferential groove 60h. The circumferential grooves 60f to 60h are provided on the circumferences of concentric circles having different radii centered at the center CT. The circumferential grooves 60f to 60h are provided at equal intervals in the radial direction Dr. Of these circumferential grooves 60f to 60h, two adjacent to each other in the radial direction Dr are referred to as a third circumferential groove 63 and a fourth circumferential groove 64.

[0097] The third circumferential groove 63 and the fourth circumferential groove 64 in the second zone 220 correspond to the first circumferential groove 61 and the second circumferential groove 62 in the first zone 210, respectively. For example, the relationship between the first circumferential groove 61 and the second circumferential groove 62 described above also applies to the relationship between the third circumferential groove 63 and the fourth circumferential groove 64.

[0098] In this example, the radial groove portion 70 has radial grooves 70a to 70j provided in the first zone 210, as well as radial grooves 70k to 70r provided in the second zone 220. The radial grooves 70k to 70r are arranged clockwise in the circumferential direction Dc in the following order: radial groove 70k, radial groove 70m, radial groove 70n, radial groove 70p, radial groove 70q, and radial groove 70r. The radial grooves 70k to 70r are provided at equal intervals in the circumferential direction Dc. Of these radial grooves 70k to 70r, one that intersects with the third circumferential groove 63 is referred to as the third radial groove 73, and one that intersects with the fourth circumferential groove 64 is referred to as the fourth radial groove 74.

[0099] The third radial groove 73 and the fourth radial groove 74 in the second zone 220 correspond to the first radial groove 71 and the second radial groove 72 in the first zone 210, respectively. For example, the relationship between the first radial groove 71 and the second radial groove 72 described above also applies to the relationship between the third radial groove 73 and the fourth radial groove 74.

[0100] The second zone 220 has a third hole 14c that overlaps with the third radial groove 73 in a plan view and a fourth hole 14d that overlaps with the fourth radial groove 74 in a plan view. In this example, the third hole 14c and the fourth hole 14d are not arranged on the same circumference. The third hole 14c and the fourth hole 14d may be arranged on the same circumference. Furthermore, the third hole 14c and the fourth hole 14d may be arranged at a position that overlaps with the circumferential groove portion 60 in a plan view, or at a position that overlaps with an intersection of the circumferential groove portion 60 and the radial groove portion 70.

[0101] 11, in this example, the gas introduction path 23 has a first gas introduction path 23a and a second gas introduction path 23b. In Fig. 11, the positions of the first gas introduction path 23a and the second gas introduction path 23b in a plan view are indicated by two-dot chain lines.

[0102] The first gas introduction passage 23a is provided in the first zone 210 and is connected to the cooling gas holes 14 provided in the first zone 210. The first hole 14a and the second hole 14b are connected to the first gas introduction passage 23a.

[0103] The second gas introduction passage 23b is provided in the second zone 220 and is connected to the cooling gas holes 14 provided in the second zone 220. The third hole 14c and the fourth hole 14d are connected to the second gas introduction passage 23b.

[0104] The first gas introduction path 23a and the second gas introduction path 23b are each provided in a substantially annular shape in a plan view. For example, the second gas introduction path 23b is located inside the first gas introduction path 23a in the radial direction Dr in a plan view.

[0105] The first gas introduction path 23a and the second gas introduction path 23b are connected to, for example, different gas supply units 24. That is, the gas supply unit 24 that supplies cooling gas to the third hole 14c and the fourth hole 14d is different from the gas supply unit 24 that supplies cooling gas to the first hole 14a and the second hole 14b. The cooling gas holes 14 (the third hole 14c and the fourth hole 14d) provided in the second zone 220 are controlled by, for example, a gas supply unit 24 that is different from the gas supply unit 24 that controls the cooling gas holes 14 (the first hole 14a and the second hole 14b) provided in the first zone 210. This makes it possible to separately control, for example, the cooling gas holes 14 (the first hole 14a and the second hole 14b) provided in the first zone 210 and the cooling gas holes 14 (the third hole 14c and the fourth hole 14d) provided in the second zone 220. The pressure of the cooling gas supplied to the third hole 14c and the fourth hole 14d may be the same as or different from the pressure of the cooling gas supplied to the first hole 14a and the second hole 14b, for example.

[0106] In this example, in the first zone 210, the third end 62a and the fourth end 62b of the second circumferential groove 62 are arranged so as not to overlap with the first end 61a and the second end 61b of the first circumferential groove 61 in the radial direction Dr, thereby improving the uniformity of the cooling gas distribution in the circumferential direction Dc. Furthermore, in the second zone 220, the third end 62a and the fourth end 62b of the fourth circumferential groove 64 are arranged so as not to overlap with the first end 61a and the second end 61b of the third circumferential groove 63 in the radial direction Dr, thereby improving the uniformity of the cooling gas distribution in the circumferential direction Dc.

[0107] Furthermore, by making it possible to separately control the cooling gas holes 14 (first hole 14a and second hole 14b) provided in the first zone 210 and the cooling gas holes 14 (third hole 14c and fourth hole 14d) provided in the second zone 220, the uniformity of the cooling gas distribution within the surface can be further improved.

[0108] FIG. 12 is a cross-sectional view schematically illustrating a wafer processing apparatus including an electrostatic chuck according to the embodiment. 12 , the wafer processing apparatus 500 includes a processing vessel 501, a radio-frequency power supply 504, a chucking power supply 505, an upper electrode 510, and an electrostatic chuck 100. A processing gas inlet 502 for introducing a processing gas into the processing vessel 501 and the upper electrode 510 are provided in the ceiling of the processing vessel 501. An exhaust port 503 for evacuating the interior of the processing vessel 501 is provided in the bottom plate of the processing vessel 501. The electrostatic chuck 100 is disposed below the upper electrode 510 inside the processing vessel 501. The base plate 20 and the upper electrode 510 of the electrostatic chuck 100 are connected to the radio-frequency power supply 504. The electrode layer 15 of the electrostatic chuck 100 is connected to the chucking power supply 505.

[0109] The base plate 20 and the upper electrode 510 are provided substantially parallel to each other with a predetermined gap therebetween. The processing object W is placed on the first main surface 11 located between the base plate 20 and the upper electrode 510.

[0110] When a voltage (high frequency voltage) is applied from the high frequency power supply 504 to the base plate 20 and the upper electrode 510, a high frequency discharge occurs, the processing gas introduced into the processing vessel 501 is excited and activated by the plasma, and the processing object W is processed.

[0111] When a voltage (adsorption voltage) is applied to the electrode layer 15 from the adsorption power supply 505, an electric charge is generated on the first main surface 11 side of the electrode layer 15, and the workpiece W is adsorbed and held by the electrostatic chuck 100 by electrostatic force.

[0112] FIG. 13 is a cross-sectional view schematically illustrating a wafer processing apparatus including an electrostatic chuck according to the first embodiment. 13, in this example, the multiple gas introduction paths 23 are connected to one gas supply unit 24. The cooling gas supplied from the gas supply unit 24 passes through each gas introduction path 23 and is supplied to each cooling gas hole 14. In this way, the multiple cooling gas holes 14 are controlled by one gas supply unit 24.

[0113] FIG. 14 is a cross-sectional view schematically showing a wafer processing apparatus including an electrostatic chuck according to a modified example of the first embodiment. 14, in this example, the gas introduction path 23 branches inside the base plate 20. The gas introduction path 23 has a plurality of first portions 26a (gas outlet paths) that communicate with each cooling gas hole 14, a second portion 26b (gas crossing path) that extends in the horizontal direction and aggregates the plurality of first portions 26a, and a third portion 26c (gas inlet path) that extends from the second portion 26b to the back surface of the base plate 20.

[0114] The third portion 26c is connected to the gas supply unit 24. The cooling gas supplied from the gas supply unit 24 passes through the third portion 26c, the second portion 26b, and each of the first portions 26a, and is supplied to each of the cooling gas holes 14. In this way, the multiple cooling gas holes 14 are controlled by a single gas supply unit 24.

[0115] As described above, according to the embodiments, an electrostatic chuck and a semiconductor manufacturing apparatus are provided that can improve the uniformity of the cooling gas distribution in the circumferential direction.

[0116] The above describes the embodiments of the present invention. However, the present invention is not limited to these descriptions. Design modifications made by a person skilled in the art to the above-described embodiments are also included within the scope of the present invention as long as they include the features of the present invention. For example, the shape, dimensions, materials, arrangement, installation form, etc. of each element of the electrostatic chuck are not limited to those exemplified and can be modified as appropriate. Furthermore, the elements of each of the above-described embodiments can be combined to the extent technically possible, and such combinations are also included within the scope of the present invention as long as they include the features of the present invention. [Explanation of symbols]

[0117] 10, 10A to 10F ceramic dielectric substrate, 10a outer edge, 11 first main surface, 11a flat portion, 11b protrusion portion, 12 second main surface, 13 groove portion, 14 cooling gas hole, 14a to 14d first to fourth holes, 15 electrode layer (attraction electrode), 16 connection portion, 20 base plate, 20a upper portion, 20b lower portion, 21 input path, 22 output path, 23 gas introduction path, 24 gas supply portion, 23a, 23b first and second gas introduction paths, 25 communication path, 30 heater, 41, 42 first and second porous portions, 60 circumferential groove portion, 26a to 26c first to third portions, 60a to 60h circumferential groove, 61 first circumferential groove 61a, 61b first and second end portions, 61c central region, 61d, 61e first and second end regions, 62 second circumferential groove, 62a, 62b third and fourth end portions, 63, 64 third and fourth circumferential grooves, 70 radial groove portion, 70a to 70r radial grooves, 71 to 74 first to fourth radial grooves, 100 electrostatic chuck, 210, 220 first and second zones, 500 semiconductor manufacturing apparatus, 501 processing vessel, 502 processing gas inlet, 503 exhaust port, 504 high frequency power source, 505 chucking power source, 510 upper electrode, CL center line, CT center, D1, D2 distance, Dc circumferential direction, Dr radial direction, IL1 to IL4 imaginary lines, P1, P2 Intersection, R1, R2 area, W processing object

Claims

1. a ceramic dielectric substrate that is circular in plan view; a base plate supporting the ceramic dielectric substrate; Equipped with the ceramic dielectric substrate has a first main surface on which an object to be processed is placed, a second main surface opposite to the first main surface, a groove portion recessed from the first main surface toward the second main surface, and a plurality of cooling gas holes that penetrate between the groove portion and the second main surface and allow a cooling gas to pass through; the groove portion includes a first circumferential groove extending in the circumferential direction, a second circumferential groove extending in the circumferential direction and at least a portion of which is adjacent to the first circumferential groove in the radial direction, a third circumferential groove extending in the circumferential direction and at least a portion of which is adjacent to the second circumferential groove in the radial direction, a first radial groove extending in the radial direction and intersecting with the first circumferential groove, and a second radial groove extending in the radial direction and intersecting with the second circumferential groove, the plurality of cooling gas holes include first holes overlapping with the first radial grooves in a plan view and second holes overlapping with the second radial grooves in a plan view, the base plate has a gas introduction passage for supplying the cooling gas to the first hole and the second hole; the first circumferential groove has a first end portion located on one end side in the circumferential direction and a second end portion located on the other end side in the circumferential direction, the second circumferential groove has a third end portion located on the one end side in the circumferential direction and a fourth end portion located on the other end side in the circumferential direction, the third circumferential groove has a fifth end portion located on the one end side in the circumferential direction and a sixth end portion located on the other end side in the circumferential direction, the third end and the fourth end do not overlap with the first end in the radial direction, and the fifth end and the sixth end do not overlap with the third end in the radial direction.

2. a ceramic dielectric substrate that is circular in plan view; a base plate supporting the ceramic dielectric substrate; Equipped with the ceramic dielectric substrate has a first main surface on which an object to be processed is placed, a second main surface opposite to the first main surface, a groove portion recessed from the first main surface toward the second main surface, and a plurality of cooling gas holes that penetrate between the groove portion and the second main surface and allow a cooling gas to pass through; the groove portion includes a first circumferential groove extending in the circumferential direction, a second circumferential groove extending in the circumferential direction and at least a portion of which is adjacent to the first circumferential groove in the radial direction, a third circumferential groove extending in the circumferential direction and at least a portion of which is adjacent to the second circumferential groove in the radial direction, a first radial groove extending in the radial direction and intersecting with the first circumferential groove, and a second radial groove extending in the radial direction and intersecting with the second circumferential groove, the plurality of cooling gas holes include a first hole overlapping with the first circumferential groove in a plan view and a second hole overlapping with the second circumferential groove in a plan view, the base plate has a gas introduction passage for supplying the cooling gas to the first hole and the second hole; the first circumferential groove has a first end portion located on one end side in the circumferential direction and a second end portion located on the other end side in the circumferential direction, the second circumferential groove has a third end portion located on the one end side in the circumferential direction and a fourth end portion located on the other end side in the circumferential direction, the third circumferential groove has a fifth end portion located on the one end side in the circumferential direction and a sixth end portion located on the other end side in the circumferential direction, the third end and the fourth end do not overlap with the first end in the radial direction, and the fifth end and the sixth end do not overlap with the third end in the radial direction.

3. 3. The electrostatic chuck according to claim 1, wherein a distance from an intersection of the first radial groove and the first circumferential groove to the first hole is equal to a distance from an intersection of the second radial groove and the second circumferential groove to the second hole.

4. 4. The electrostatic chuck according to claim 1, wherein the third end and the fourth end do not overlap with the second end in the radial direction.

5. the first circumferential groove has a central region including a center in the circumferential direction, 5. The electrostatic chuck according to claim 1, wherein the third end overlaps with the central region in the radial direction.

6. 6. The electrostatic chuck according to claim 5, wherein the third end portion is located closer to the other end portion in the circumferential direction than the center in the circumferential direction of the first circumferential groove.

7. 7. The electrostatic chuck according to claim 6, wherein the fourth end is located closer to the other end in the circumferential direction than the second end.

8. 8. The electrostatic chuck according to claim 1, further comprising a heater for heating the ceramic dielectric substrate.

9. An electrostatic chuck according to any one of claims 1 to 8; a gas supply unit that supplies the cooling gas to the first hole and the second hole through the gas introduction path; A semiconductor manufacturing apparatus comprising:

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