JP7730458B2 - Electrostatic chuck and semiconductor manufacturing equipment - Google Patents

Description

Aspects of the present invention generally relate to electrostatic chucks and semiconductor manufacturing equipment.

Electrostatic chucks are used in plasma processing chambers used for etching, CVD (Chemical Vapor Deposition), sputtering, ion implantation, ashing, and other processes to attract and hold semiconductor wafers, glass substrates, and other workpieces. Electrostatic chucks apply electrostatic attraction power to built-in electrodes, and use electrostatic force to attract substrates such as silicon wafers.

With the miniaturization of semiconductor devices in recent years, there is a demand for even greater improvement in the precision of wafer processing using processes 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.

One known method for controlling the surface temperature of an electrostatic chuck is to provide grooves that communicate with cooling gas holes that supply cooling gas to the surface of the electrostatic chuck (ceramic dielectric substrate), and distribute the cooling gas over the surface of the electrostatic chuck through these grooves. For example, Patent Document 1 discloses a groove pattern in which multiple circumferential grooves extending in the circumferential direction are arranged concentrically, and these circumferential grooves are further connected to radial grooves extending in the radial direction, thereby distributing cooling gas over the surface of the electrostatic chuck.

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 result in a decrease in the uniformity of the cooling gas distribution in the circumferential direction.

Japanese Patent Application Laid-Open No. 2001-110883

The present invention was developed based on the recognition of these issues, and aims to provide an electrostatic chuck and semiconductor manufacturing apparatus that can improve the uniformity of cooling gas distribution in the circumferential direction.

A first invention comprises a ceramic dielectric substrate that is circular in plan view, and a base plate that supports the ceramic dielectric substrate. The ceramic dielectric substrate has a first main surface on which an object to be processed is placed, a second main surface opposite the first main surface, a groove recessed from the first main surface toward the second main surface, and a plurality of cooling gas holes that penetrate between the groove and the second main surface and allow cooling gas to pass through. The groove comprises a first circumferential groove that extends in the 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 the radial direction, a first radial groove that extends in the radial direction and intersects the first circumferential groove, and a second circumferential groove that extends in the radial direction and intersects 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 for supplying the cooling gas to the first holes and the second holes, the first circumferential groove having a first end located at one end in the circumferential direction and a second end located at the other end in the circumferential direction, the second circumferential groove having a third end located at the one end in the circumferential direction and a fourth end located at the other end in the circumferential direction, the third end and the fourth end not overlapping the first end in the radial direction.

With this electrostatic chuck, the third and fourth ends of the second circumferential groove are positioned so as not to overlap the first end of the first circumferential groove in the radial direction, preventing the ends of the first and second circumferential grooves from being linearly aligned in the radial direction. This prevents the creation of areas where cooling gas is difficult to reach, improving the uniformity of 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, making it impossible to arrange multiple cooling gas holes on the same circumference. If multiple cooling gas holes are not arranged on the same circumference, the shape of the groove pattern may result in a decrease in the uniformity of cooling gas distribution in the circumferential direction. In contrast, with this electrostatic chuck, the uniformity of cooling gas distribution in the circumferential direction can be improved even when multiple cooling gas holes are not arranged on the same circumference.

A second invention comprises a ceramic dielectric substrate that is circular in 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 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 cooling gas to pass through, and the groove portion comprises a first circumferential groove that extends in the circumferential direction, a second circumferential groove that extends in the circumferential direction and at least a portion of which is adjacent to the first circumferential groove in the radial direction, a first radial groove that extends in the radial direction and intersects the first circumferential groove, and a second circumferential groove that extends in the radial direction and intersects the second circumferential groove. 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 at one end in the circumferential direction and a second end located at the other end in the circumferential direction, the second circumferential groove having a third end located at the one end in the circumferential direction and a fourth end located at the other end in the circumferential direction, the third end and the fourth end not overlapping the first end in the radial direction.

With this electrostatic chuck, the third and fourth ends of the second circumferential groove are positioned so that they do not overlap the first end of the first circumferential groove in the radial direction, preventing the ends of the first and second circumferential grooves from being aligned in a straight line in the radial direction. This prevents the creation of areas where the cooling gas is difficult to reach, improving the uniformity of the cooling gas distribution in the circumferential direction. Furthermore, with 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.

The 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.

With this electrostatic chuck, 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, thereby improving the uniformity of the cooling gas distribution in the circumferential direction even when the first hole and the second hole are not located on the same circumference.

The 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.

With this electrostatic chuck, the third and fourth ends of the second circumferential groove are positioned so that they do not overlap the second end of the first circumferential groove in the radial direction, preventing the ends of the first and second circumferential grooves from being aligned in a straight line in the radial direction. This further prevents areas where the cooling gas is difficult to reach, further improving the uniformity of the cooling gas distribution in the circumferential direction.

The 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 that includes the center in the circumferential direction, and the third end overlaps with the central region in the radial direction.

With this electrostatic chuck, the third end of the second circumferential groove is positioned to overlap the central region of the first circumferential groove in the radial direction, further improving the uniformity of the cooling gas distribution in the circumferential direction.

A sixth aspect of the present invention is an electrostatic chuck according to the fifth aspect of the present 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.

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

The seventh invention is an 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.

With 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, further improving the uniformity of the cooling gas distribution in the circumferential direction.

The 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.

This electrostatic chuck can improve the uniformity of cooling gas distribution in the circumferential direction, even when a heater is installed.

The ninth invention is a semiconductor manufacturing apparatus comprising the electrostatic chuck of 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.

This semiconductor manufacturing equipment allows for more uniform control of the surface temperature of the electrostatic chuck, improving the accuracy of wafer processing, such as etching.

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

1 is a cross-sectional view schematically illustrating an electrostatic chuck according to a first embodiment. 1 is a plan view schematically illustrating a ceramic dielectric substrate according to a first embodiment. FIG. FIG. 2 is a plan view schematically illustrating a portion of the ceramic dielectric substrate according to the first embodiment. 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. 10 is a plan view schematically showing a ceramic dielectric substrate according to a second embodiment. FIG. 10 is a plan view schematically illustrating a portion of a ceramic dielectric substrate according to a second embodiment. FIG. 10 is a plan view schematically illustrating a portion of a ceramic dielectric substrate according to a modified example of the second embodiment. FIG. 10 is a plan view schematically showing a ceramic dielectric substrate according to a third embodiment. FIG. 11 is a plan view schematically showing a ceramic dielectric substrate according to a modified example of the third embodiment. FIG. 10 is a plan view schematically showing a ceramic dielectric substrate according to a fourth embodiment. FIG. 10 is a plan view schematically showing a ceramic dielectric substrate according to a fourth embodiment. 1 is a cross-sectional view schematically illustrating a wafer processing apparatus including an electrostatic chuck according to a first embodiment. 1 is a cross-sectional view schematically illustrating a wafer processing apparatus including an electrostatic chuck according to a first embodiment. FIG. 10 is a cross-sectional view schematically illustrating a wafer processing apparatus including an electrostatic chuck according to a modified example of the first embodiment.

Embodiments of the present invention will be described below with reference to the drawings. Note that in each drawing, similar components will be designated by the same reference numerals and detailed descriptions will be omitted where appropriate.

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 .

The ceramic dielectric substrate 10 is a flat base material made of, for example, a polycrystalline ceramic sintered body. Examples of _the crystalline material 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.

The ceramic dielectric substrate 10 has a first main surface 11, a second main surface 12, a groove 13, and multiple 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 multiple cooling gas holes 14 penetrate between the groove 13 and the second main surface 12. The multiple cooling gas holes 14 are provided to allow cooling gas to pass through. The multiple cooling gas holes 14 are in communication with the groove 13. As a result, the groove 13 diffuses the cooling gas supplied from the multiple cooling gas holes 14 to the first main surface 11. The groove 13 and the multiple cooling gas holes 14 will be described later.

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 X-Y plane. In this specification, "planar view" refers to the state when viewed along the Z direction.

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 workpiece W is placed on and supported by the protruding portions 11b. The protruding portions 11b contact the back surface of the workpiece W. By providing the protruding portions 11b, a space can be formed between the back surface of the workpiece 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, maintain a desirable state of particles adhering to the workpiece W.

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. In other words, the electrode layer 15 is formed so as to be inserted into the ceramic dielectric substrate 10. The electrode layer 15 is sintered integrally 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 also be attached to the second main surface 12.

The electrode layer 15 has 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 via hole (hollow type) that is electrically connected to the electrode layer 15, or a metal terminal connected by an appropriate method such as brazing.

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

The electrode layers 15 are provided along the first main surface 11 and the second main surface 12. The electrode layers 15 are suction electrodes for suctioning and holding the workpiece W. The electrode layers 15 may be monopolar or bipolar. The electrode layers 15 may also be tripolar or other multipolar types. The number of electrode layers 15 and the arrangement of the electrode layers 15 can be selected appropriately.

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.

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 path 21, and the other end is connected to the output path 22.

The base plate 20 also serves to regulate 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 mounted on it. On the other hand, when keeping the electrostatic chuck 100 warm, a heat-retaining medium can also be placed in the connecting path 25.

The base plate 20 is also provided with at least one gas inlet channel 23. In this example, the base plate 20 is provided with multiple gas inlet channels 23. Each gas inlet channel 23 is provided, for example, to penetrate the base plate 20 in the Z direction. Each of the multiple gas inlet channels 23 is connected to multiple cooling gas holes 14 in the ceramic dielectric substrate 10. As a result, the cooling gas introduced from the gas inlet channel 23 in the base plate 20 passes through the cooling gas holes 14 in the ceramic dielectric substrate 10 and diffuses to the first main surface 11 along the grooves 13 connected to the cooling gas holes 14. The gas inlet channel 23 may branch inside the base plate 20, as described below (see Figure 14).

Cooling gas is supplied to the cooling gas holes 14 from a gas supply unit 24 (see Figures 13 and 14). The gas supply unit 24 is connected to the gas inlet path 23 and supplies cooling gas to the cooling gas holes 14 via the gas inlet path 23. The gas supply unit 24 controls, for example, the pressure of the cooling gas being supplied and the start and stop of the supply of cooling gas.

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

In an embodiment, one gas inlet path 23 may be connected (communicate) with multiple cooling gas holes 14. In this case, too, the multiple cooling gas holes 14 connected to this single gas inlet path 23 are controlled by a single gas supply unit 24.

In this example, a first porous portion 41 and a second porous portion 42 are provided at the connection between the gas inlet 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 inlet path 23. The first porous portion 41 and the second porous portion 42 face each other in the Z direction.

The first porous portion 41 and the second porous portion 42 may be made of, for example, insulating ceramics. The first porous portion 41 and the second porous portion 42 may contain, for example, at least one of aluminum oxide (Al ₂ O ₃ ), titanium oxide (TiO ₂ ), and yttrium oxide (Y ₂ O ₃ ). The first porous portion 41 and the second porous portion 42 may be provided as needed and may be omitted.

The heater 30 heats the ceramic dielectric substrate 10. By heating the ceramic dielectric substrate 10, the heater 30 heats the workpiece 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, for example, via an adhesive layer. The heater 30 is bonded to the ceramic dielectric substrate 10, for example, via an adhesive layer.

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 may be provided as needed and may be omitted.

FIG. 2 is a plan view schematically showing 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.

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 the direction along the circumference of a circle centered at the center CT of the ceramic dielectric substrate 10. The radial direction Dr is the direction from the center CT of the ceramic dielectric substrate 10 toward the outer edge 10a of the ceramic dielectric substrate 10.

In this example, the circumferential groove portion 60 has multiple circumferential grooves 60a-60e aligned in the radial direction Dr. The circumferential grooves 60a-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, circumferential groove 60e. The circumferential grooves 60a-60e are arranged on concentric circles with different radii centered on the center CT. The circumferential grooves 60a-60e are arranged at equal intervals in the radial direction Dr. Of these circumferential grooves 60a-60e, two adjacent ones in the radial direction Dr are referred to as the first circumferential groove 61 and the second circumferential groove 62.

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 radially inward of the first circumferential groove 61 in the radial direction Dr 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 located radially outward of the first circumferential groove 61 in the radial direction Dr 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.

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.

The number of circumferential grooves aligned in the radial direction Dr is not limited to five, but may be two or more. Furthermore, the spacing between the circumferential grooves aligned in the radial direction Dr does not have to be equal.

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

In this example, the radial groove portion 70 has multiple 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 arranged at equal intervals in the circumferential direction Dc. Of these radial grooves 70a to 70j, the one that intersects with the first circumferential groove 61 is referred to as the first radial groove 71, and the 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.

It is preferable that at least a portion of the second radial groove 72 overlaps with the first radial groove 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. In other words, in this example, all of the second radial grooves 72 overlap with the first radial groove 71 in the circumferential direction Dc.

The number of radial grooves aligned in the circumferential direction Dc is not limited to 10, but may be two 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. Furthermore, the spacing between the radial grooves aligned in the circumferential direction Dc does not have to be equal.

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.

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. In other words, the imaginary line IL3 connecting the third end 62a to the center CT intersects with the imaginary line IL1 connecting the first end 61a to 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. In other words, the imaginary line IL4 connecting the fourth end 62b to the center CT intersects with the imaginary line IL1.

By arranging the third end 62a and fourth end 62b of the second circumferential groove 62 so that they do not overlap with the first end 61a of the first circumferential groove 61 in the radial direction Dr, the ends of the first circumferential groove 61 and the second circumferential groove 62 are prevented from aligning in a straight line in the radial direction Dr. This prevents the creation of areas where the cooling gas is difficult to reach, improving the uniformity of the cooling gas distribution in the circumferential direction Dc.

In addition, 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 within the ceramic dielectric substrate 10, multiple cooling gas holes 14 may be provided to avoid the heater 30, making it impossible to arrange multiple cooling gas holes 14 on the same circumference. If multiple cooling gas holes 14 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 Dc may be reduced. 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.

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. In other words, 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. In other words, in this example, the imaginary line IL4 intersects with the imaginary line IL2.

By arranging the third end 62a and fourth end 62b of the second circumferential groove 62 so that they do not overlap with the second end 61b of the first circumferential groove 61 in the radial direction Dr, the ends of the first circumferential groove 61 and the second circumferential groove 62 are prevented from aligning in a straight line in the radial direction Dr. This further prevents the creation of areas where the cooling gas is difficult to reach, further improving the uniformity of the cooling gas distribution in the circumferential direction Dc.

The third end 62a may overlap the second end 61b in the radial direction Dr. In other words, 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. In other words, the imaginary line IL4 may be located on the same line as the imaginary line IL2.

In this example, the multiple cooling gas holes 14 are positioned so as to overlap the radial grooves 70a to 70j in a plan view. The multiple cooling gas holes 14 include a first hole 14a that overlaps the first radial groove 71 in a plan view, and a second hole 14b that overlaps 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 second hole 14b, are arranged on the same circumference centered on the center CT.

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.

Furthermore, 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 hole 14a and the second hole 14b are not arranged on the same circumference.

Note that distance D1 and distance D2 may be different from each other. Furthermore, distance D1 and distance D2 may both be zero. In other words, first hole 14a may be located at a position overlapping intersection point P1, and second hole 14b may be located at a position overlapping intersection point P2. Examples of this type are described in Figures 8 and 9.

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 positioned offset from the first circumferential groove 61 in the radial direction Dr.

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 at one end in the circumferential direction Dc and includes the first end 61a. The second end region 61e is located at the other end in the circumferential direction Dc and includes the second end 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 Figure 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 closest to one end can be considered the first end region 61d, the region closest to the other end can be considered the second end region 61e, and the region located in the center can be considered the central region 61c.

The third end 62a of the second circumferential groove 62 overlaps, for example, with the central region 61c of the first circumferential groove 61 in the radial direction Dr. By positioning the third end 62a of the second circumferential groove 62 so that it overlaps 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.

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 preferably does not 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.

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.

The third end 62a of the second circumferential groove 62 may overlap the first end region 61d of the first circumferential groove 61 in the radial direction Dr, or may overlap the second end region 61e of the first circumferential groove 61. Furthermore, 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. In other words, the second circumferential groove 62 may overlap the center line CL in a plan view. Furthermore, 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. In other words, the fourth end 62b of the second circumferential groove 62 may overlap the first circumferential groove 61 in the radial direction Dr.

In addition, in this example, the end portion of circumferential groove 60d on one side in the circumferential direction Dc overlaps with the end portion (first end portion 61a) of circumferential groove 60b (first circumferential groove 61) on one side in the circumferential direction Dc in the radial direction Dr. In addition, the end portion of circumferential groove 60d on the other side in the circumferential direction Dc overlaps with the end portion (second end portion 61b) of circumferential groove 60b (first circumferential groove 61) on the other 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 these two circumferential grooves may overlap in the radial direction Dr.

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 the 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, but otherwise the ceramic dielectric substrate 10 according to the first embodiment is the same as that shown in Figs.

In this example, the third end 62a and fourth end 62b of the second circumferential groove 62 are positioned so that they do not overlap with the first end 61a and 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.

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 hole 14a and the second hole 14b are not arranged on the same circumference.

FIG. 5 is a plan view schematically showing 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 .

In this example, 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. 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. Furthermore, 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. Furthermore, 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.

By positioning the third end 62a and fourth end 62b of the second circumferential groove 62 so that they do not overlap the first end 61a and second end 61b of the first circumferential groove 61 in the radial direction Dr, the ends of the first circumferential groove 61 and the second circumferential groove 62 are prevented from aligning linearly in the radial direction Dr. This prevents the creation of areas where the cooling gas is difficult to reach, improving 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.

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 hole 14a and the second hole 14b are not arranged on the same circumference.

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.

In this example, the third end 62a and fourth end 62b of the second circumferential groove 62 are positioned so that they do not overlap with the first end 61a and 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 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 when the first hole 14a and the second hole 14b are located at overlapping positions in the radial direction Dr.

FIG. 8 is a plan view schematically showing a ceramic dielectric substrate according to the 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 hole 14a is provided at a position overlapping with the intersection P1, and the second hole 14b is provided at a position overlapping with the intersection 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.

In this example, the third end 62a and fourth end 62b of the second circumferential groove 62 are positioned so that they do not overlap with the first end 61a and 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.

In this way, the cooling gas holes 14 may be provided at positions overlapping with circumferential grooves (first circumferential groove 61 and second circumferential groove 62), radial grooves (first radial groove 71 and second radial groove 72), or intersections between circumferential grooves and radial grooves (intersections P1 and P2).

FIG. 9 is a plan view schematically showing 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.

In this example, the third end 62a and fourth end 62b of the second circumferential groove 62 are positioned so that they do not overlap with the first end 61a and 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.

10 and 11 are plan views schematically showing a 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.

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.

As shown in FIG. 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.

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 also 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 the intersection of the circumferential groove portion 60 and the radial groove portion 70.

In this example, the circumferential groove portion 60 has circumferential grooves 60a-60e provided in the first zone 210, as well as circumferential grooves 60f-60h provided in the second zone 220. The circumferential grooves 60f-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-60h are arranged on concentric circles with different radii centered on the center CT. The circumferential grooves 60f-60h are arranged at equal intervals in the radial direction Dr. Of these circumferential grooves 60f-60h, two adjacent ones in the radial direction Dr are designated the third circumferential groove 63 and the fourth circumferential groove 64.

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.

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

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.

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 also 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 the intersection of the circumferential groove portion 60 and the radial groove portion 70.

As shown in FIG. 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.

The first gas inlet 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 inlet passage 23a.

The second gas inlet 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 inlet passage 23b.

The first gas introduction path 23a and the second gas introduction path 23b are each provided in a generally annular shape in a plan view. For example, the second gas introduction path 23b is located radially inward of the first gas introduction path 23a in a plan view.

The first gas inlet path 23a and the second gas inlet 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 (third hole 14c and 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 (first hole 14a and second hole 14b) provided in the first zone 210. This makes it possible to separately control, for example, 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 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.

In this example, in the first zone 210, the third end 62a and fourth end 62b of the second circumferential groove 62 are positioned so that they do not overlap with the first end 61a and 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 fourth end 62b of the fourth circumferential groove 64 are positioned so that they do not overlap with the first end 61a and 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.

In addition, 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.

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, an attraction power supply 505, an upper electrode 510, and an electrostatic chuck 100. A processing gas inlet 502 for introducing a processing gas into the interior 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 attraction power supply 505.

The base plate 20 and upper electrode 510 are arranged approximately parallel to each other at a predetermined distance. The workpiece W is placed on the first main surface 11 located between the base plate 20 and the upper electrode 510.

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

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 due to electrostatic force.

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 inlet paths 23 are connected to one gas supply unit 24. The cooling gas supplied from the gas supply unit 24 passes through each gas inlet path 23 and is supplied to each cooling gas hole 14. In this way, the multiple cooling gas holes 14 are controlled by the single gas supply unit 24.

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

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. As a result, multiple cooling gas holes 14 are controlled by a single gas supply unit 24.

As described above, the embodiments provide an electrostatic chuck and semiconductor manufacturing apparatus that can improve the uniformity of cooling gas distribution in the circumferential direction.

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.

10, 10A to 10F: Ceramic dielectric substrate; 10a: Outer edge; 11: First main surface; 11a: Planar portion; 11b: Protrusion; 12: Second main surface; 13: Groove; 14: Cooling gas hole; 14a to 14d: First to fourth holes; 15: Electrode layer (adsorption 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; 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 Adsorption power source, 510 Upper electrode, CL Center line, CT Center, D1, D2 Distance, Dc Circumferential direction, Dr Radial direction, IL1 to IL4 Virtual straight lines, P1, P2: Intersection, R1, R2: Area, W: Processing object

Claims (9)

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 . 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 . An electrostatic chuck as described in claim 1 or 2, 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. An electrostatic chuck according to any one of claims 1 to 3, characterized in that the third end and the fourth end do not overlap with the second end in the radial direction. 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. An electrostatic chuck as described in claim 5, characterized in that the third end is located closer to the other end in the circumferential direction than the circumferential center of the first circumferential groove. An electrostatic chuck as described in claim 6, characterized in that the fourth end is located closer to the other end in the circumferential direction than the second end. An electrostatic chuck according to any one of claims 1 to 7, further comprising a heater for heating the ceramic dielectric substrate. 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: