Holding device, and method for manufacturing a holding device

Abstract

This invention provides a technology for continuously performing stable plasma treatment on a substrate being held in a holding device. [Solution] The holding device comprises a substrate base formed in the shape of a plate from ceramics and having a mounting surface on which a substrate is placed; a focus ring base formed in the shape of a ring from ceramics and positioned on the outer circumference of the substrate base; a base having a first joining surface to which the substrate base is joined, a second joining surface to which the focus ring base is joined, and an intermediate portion located between the first joining surface and the second joining surface; and an insulating portion formed from ceramics and positioned in the gap formed between the substrate base and the focus ring base to cover the intermediate portion.

Description

Technical Field

[0001] The present invention relates to a holding device and a method for manufacturing the holding device.

Background Art

[0002] Conventionally, a holding device for holding a substrate has been known (for example, Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, even with prior arts such as Patent Documents 1 and 2, there is still room for improvement in the technology of continuously and stably forming plasma for processing a substrate in a holding device.

[0005] The present invention has been made to solve the above-described problems, and an object thereof is to provide a technology for continuously and stably forming plasma for processing a substrate in a holding device.

Means for Solving the Problems

[0006] The present invention has been made to solve at least a part of the above-described problems and can be realized in the following forms.

[0007] (1) According to one embodiment of the present invention, a holding device for holding a substrate is provided. The holding device comprises a substrate base formed in the shape of a plate from ceramics and having a mounting surface on which the substrate is placed; a focus ring base formed in the shape of an annular form from ceramics and disposed on the outer circumference of the substrate base; a base having a first joining surface to which the substrate base is joined, a second joining surface to which the focus ring base is joined, and an intermediate portion located between the first joining surface and the second joining surface; and an insulating portion formed from ceramics and disposed in the gap formed between the substrate base and the focus ring base to cover the intermediate portion.

[0008] In this configuration, the base has an intermediate portion located between a first bonding surface to which the substrate material is joined and a second bonding surface to which the focus ring material is joined. The intermediate portion is made of ceramics and is covered by an insulating portion that is placed in the gap formed between the substrate material and the focus ring material. As a result, for example, even if the holding device is used in a process that utilizes plasma, the intermediate portion will not be exposed to the environment in which the plasma is formed, and the plasma sheath will not change easily even if the holding device is used continuously. Therefore, the plasma can be formed continuously and stably.

[0009] (2) In the above-described holding device, the porosity of the ceramics forming the insulating portion may be greater than the porosity of the ceramics forming the substrate material and the porosity of the ceramics forming the focus ring material. With this configuration, the porosity of the ceramics forming the insulating portion is greater than the porosity of the ceramics forming the substrate material and the porosity of the ceramics forming the focus ring material. This difference in porosity is due to the insulating portion being formed to fill the gap between the substrate material and the focus ring material. That is, the insulating portion is formed according to the shape of the gap formed between the substrate material and the focus ring material, and exposure of the intermediate portion can be further suppressed. In addition, the insulating portion with a relatively large porosity has relatively high adhesion to the substrate material and the focus ring material, respectively. As a result, changes in the plasma sheath can be further suppressed, and the plasma can be formed more continuously and stably.

[0010] (3) In the above-described holding device, the thermal conductivity of the ceramics forming the insulating portion may be smaller than the thermal conductivity of the ceramics forming the substrate material and the thermal conductivity of the ceramics forming the focus ring material. With this configuration, the thermal conductivity of the ceramics forming the insulating portion is smaller than the thermal conductivity of the ceramics forming the substrate material and the thermal conductivity of the ceramics forming the focus ring material. This difference in thermal conductivity is due to the insulating portion being formed to fill the gap formed between the substrate material and the focus ring material, unlike the substrate material and the focus ring material. That is, the insulating portion is formed according to the shape of the gap formed between the substrate material and the focus ring material, and exposure of the intermediate portion can be further suppressed. In addition, the insulating portion with relatively low thermal conductivity can suppress heat transfer between the substrate material and the focus ring material. As a result, changes in the plasma sheath can be further suppressed, and the plasma can be formed more continuously and stably.

[0011] (4) In the above-described form of the holding device, the base has a step formed by the intermediate portion between the first bonding surface and the second bonding surface, and the intermediate portion may be formed so as to move away from the central axis of the holding device from the first bonding surface side toward the second bonding surface side. With this configuration, the base has a step formed by the intermediate portion between the first bonding surface and the second bonding surface, and the substrate material for the substrate that is bonded to the first bonding surface and the substrate material for the focus ring that is bonded to the second bonding surface are positioned at offset locations in the direction along the central axis of the holding device. Furthermore, since the intermediate portion is formed so as to move away from the central axis of the holding device from the first bonding surface side toward the second bonding surface side, the intermediate portion is more easily visible from between the substrate material for the substrate and the substrate material for the focus ring. This makes it easier to form an insulating portion that covers the intermediate portion, and thus further suppresses exposure of the intermediate portion. Therefore, the plasma can be formed more continuously and stably.

[0012] (5) In the above-described form of the holding device, the length of the intermediate portion in the cross-section including the central axis of the holding device may be 1 mm or more. With this configuration, the base has an intermediate portion with a length of 1 mm or more in the cross-section including the central axis of the holding device. This makes it easier for an insulating portion to be formed on the intermediate portion so as to cover it, and thus further suppresses exposure of the intermediate portion. Therefore, the plasma can be formed more continuously and stably.

[0013] (6) In the above-described holding device, the inner circumference of the focus ring substrate has a first chamfer on the side opposite to the side joined to the base, and in a cross section including the central axis of the holding device, if the thickness of the focus ring substrate in the stacking direction of the substrate and the focus ring substrate and the base is D and the length of the first chamfer is L, then the following equation (1) may be satisfied. 0.2 ≤ L / D ≤ ​​1.4 ···(1) In this configuration, the inner circumference of the focus ring substrate has a first chamfer on the side opposite to the side joined to the base. The first chamfer is formed such that, in a cross-section including the central axis of the holding device, the relationship between the thickness D of the focus ring substrate and the length L of the first chamfer satisfies equation (1). As a result, when forming an insulating portion to cover the intermediate portion, the material forming the insulating portion can easily pass between the substrate material and the focus ring substrate, making it easier to form an insulating portion on the intermediate portion. Therefore, exposure of the intermediate portion can be further suppressed, and the plasma can be formed more continuously and stably.

[0014] (7) In the above-described holding device, the base has a step formed by the intermediate portion between the first joining surface and the second joining surface, the intermediate portion is formed so as to move away from the central axis of the holding device from the first joining surface side toward the second joining surface side, the inner circumference of the focus ring substrate has a first chamfer on the side opposite to the side joined to the base, the outer circumference of the substrate has a second chamfer on the side joined to the base, and in a cross-section including the central axis of the holding device, the angle between the direction of the normal to the intermediate portion and the direction of the first normal to the first chamfer is 90 degrees or less, and the angle between the direction of the normal to the intermediate portion and the direction of the second normal to the second chamfer may also be 90 degrees or less. The angle between the direction of the normal to the intermediate section and the direction of the first normal to the first chamfered section, and the angle between the direction of the normal to the intermediate section and the direction of the second normal to the second chamfered section, are both 90 degrees or less. As a result, when forming an insulating section to cover the intermediate section, the material forming the insulating section can easily pass between the substrate material and the focus ring material, making it easier to form an insulating section on the intermediate section. Therefore, exposure of the intermediate section can be further suppressed, and the plasma can be formed more continuously and stably.

[0015] (8) According to another embodiment of the present invention, a method for manufacturing a holding device is provided, comprising: a substrate base formed in the shape of a plate from ceramics and having a mounting surface on which a substrate is placed; a focus ring base formed in the shape of an annular form from ceramics and disposed on the outer circumference of the substrate base; a base having a first bonding surface to which the substrate base is joined, a second bonding surface to which the focus ring base is joined, and an intermediate portion located between the first bonding surface and the second bonding surface; and an insulating portion formed from ceramics and disposed in the gap formed between the substrate base and the focus ring base to cover the intermediate portion. The method for manufacturing this holding device comprises a preparation step of preparing the substrate base, the focus ring base, and the base; a bonding step of joining the substrate base and the focus ring base to the base; and an insulating portion forming step, after the bonding step, of forming the insulating portion in the gap formed between the substrate base and the focus ring base using ceramic thermal spraying. In this configuration, after the substrate material for the substrate and the substrate material for the focus ring are joined to the base in the bonding process, an insulating part is formed to cover the middle part of the base using ceramic spraying in the insulating part formation process. As a result, exposure of the middle part is suppressed, and the plasma sheath is less likely to change even if the holding device is used continuously in processes using plasma. Therefore, it is possible to manufacture a holding device that can continuously and stably form plasma.

[0016] (9) In the method for manufacturing the holding device of the above form, the preparation step is to prepare: a focus ring substrate having a first chamfered portion on its inner circumference, wherein in a cross section including the central axis of the focus ring substrate, the relationship between its own thickness D and the length L of the first chamfered portion is 0.2 ≤ L / D ≤ ​​1.4; a substrate having a second chamfered portion on its outer circumference; and a base having a step formed by the intermediate portion between the first joining surface and the second joining surface, wherein the intermediate portion is formed so as to move away from the central axis of the base from the first joining surface side to the second joining surface side, and in a cross section including the central axis of the base, the length of the intermediate portion is 1 mm or more. Furthermore, in the joining step, the focus ring substrate may be positioned relative to the base such that the first chamfered portion is located on the side opposite to the side joined to the base, and the angle between the direction of the normal to the intermediate portion and the direction of the first normal to the first chamfered portion is 90 degrees or less in a cross-section including the central axis of the base, and the substrate for the base may be positioned relative to the base such that the second chamfered portion is located on the side joined to the base, and the angle between the direction of the normal to the intermediate portion and the direction of the second normal to the second chamfered portion is 90 degrees or less in a cross-section including the central axis of the base, and the substrate for the base and the focus ring substrate may be joined to the base. With this configuration, in the preparation step, a base having an intermediate portion with a length of 1 mm or more in a cross-section including the central axis of the holding device is prepared. This makes it easier to form an insulating portion on the intermediate portion so as to cover it in the insulating portion forming step. Furthermore, in the preparation process, a focus ring substrate having a first chamfered portion is prepared on the side opposite to the side that will be joined to the base of the inner circumference, and a substrate having a second chamfered portion is prepared on the side that will be joined to the base of the outer circumference. In the joining process, when the substrate and the focus ring substrate are joined to the base, the angle between the direction of the normal of the intermediate portion and the direction of the first normal of the first chamfered portion, and the angle between the direction of the normal of the intermediate portion and the direction of the second normal of the second chamfered portion, are both 90 degrees or less. As a result, the material that forms the insulating portion can easily pass between the substrate and the focus ring substrate, making it easier to form an insulating portion on the intermediate portion.Therefore, since the exposure of the intermediate portion is further suppressed, a holding device capable of forming plasma more continuously and stably can be manufactured.

[0017] Note that the present invention can be realized in various aspects. For example, a repair method of a holding device, a system including the holding device, a control method of the holding device and a system including the holding device, a computer program for causing a substrate to be held in the holding device and the system including the holding device, a server device for distributing the computer program, a non-transitory storage medium storing the computer program, and the like.

Brief Description of the Drawings

[0018] [Figure 1] It is a perspective view of the holding device of the first embodiment. [Figure 2] It is a cross-sectional view of the holding device of the first embodiment. [Figure 3] It is an enlarged view of part A in FIG. 2. [Figure 4] It is an enlarged view of part B in FIG. 3. [Figure 5] It is a first diagram for explaining the manufacturing method of the holding device of the first embodiment. [Figure 6] It is a second diagram for explaining the manufacturing method of the holding device of the first embodiment. [Figure 7] It is a cross-sectional view of the holding device of the second embodiment. [Figure 8] It is an enlarged view of part C in FIG. 7. [Figure 9] It is a cross-sectional view of the holding device of the third embodiment. [Figure 10] It is an enlarged view of part D in FIG. 9. [Figure 11] It is a cross-sectional view of the holding device of the fourth embodiment. [Figure 12] It is an enlarged view of part E in FIG. 11. <00C0099> [Figure 13] It is a cross-sectional view of the holding device of the fifth embodiment. <00CCCO2>It is an enlarged view of part F in FIG. 13. [Figure 15]This is a cross-sectional view of a first modified example of the holding device of the first embodiment. [Figure 16] This is a cross-sectional view of a second modified example of the holding device of the first embodiment. [Modes for carrying out the invention]

[0019] <First Embodiment> Figure 1 is a perspective view of the holding device 1 of this embodiment. Figure 2 is a cross-sectional view of the holding device 1 of this embodiment. Figure 3 is an enlarged view of part A in Figure 2. The holding device 1 of this embodiment is an electrostatic chuck that holds a substrate W by attracting it with electrostatic force. The electrostatic chuck is used, for example, as a table on which to place the substrate W in an etching process using plasma in a chamber equipped with the electrostatic chuck. The holding device 1 of this embodiment comprises a substrate base material 10, a focus ring base material 20, a base 30, and an insulating part 41. In the holding device 1, the substrate base material 10 and the focus ring base material 20 are stacked on the base 30, respectively. In Figures 1, 2, and 3, for convenience, the stacking direction of the substrate base material 10 and the focus ring base material 20 and the base 30 is shown as the z-axis direction, the direction perpendicular to the z-axis is shown as the x-axis direction, and the direction perpendicular to the z-axis and x-axis is shown as the y-axis direction. For the sake of explanation, the relative sizes of the substrate material 10, focus ring material 20, base 30, and insulating part 41 shown in Figures 1, 2, and 3 do not reflect the actual relationships.

[0020] The substrate base material 10 is formed in a plate shape from ceramics and has a mounting surface 11 on which the substrate W is placed. As shown in Figure 1, the substrate base material 10 has a disc shape. In this embodiment, the substrate base material 10 is made of aluminum nitride (AlN). The substrate base material 10 may be made of other ceramics such as aluminum oxide (Al2O3). The substrate base material 10 incorporates a chuck electrode 12 made of a conductive material. The chuck electrode 12 is connected to an external power supply via electrode terminals (not shown). When power is supplied from an external power supply, the chuck electrode 12 generates an electrostatic attraction force that is capable of adsorbing and holding the substrate W on the mounting surface 11. In addition to the chuck electrode 12, the substrate base material 10 may also have high-frequency electrodes or heater electrodes.

[0021] In this embodiment, the outer periphery 10a of the substrate material 10 has a second chamfered portion 13 on the side that is joined to the base 30, as shown in Figures 2 and 3. The second chamfered portion 13 is formed by chamfering the corner of the outer periphery 10a of the substrate material 10 that is joined to the base 30. The second chamfered portion 13 is formed around the entire circumference of the outer periphery 10a of the substrate material 10.

[0022] The focus ring substrate 20 is formed in an annular shape from ceramics and is positioned outside the outer circumference of the substrate 10. The focus ring substrate 20 has an annular shape. In this embodiment, the focus ring substrate 20 is made of aluminum nitride. However, the focus ring substrate 20 may be made of other ceramics such as silicon carbide. The focus ring substrate 20 has a mounting surface 21 on which the focus ring FR is placed and a chuck electrode 22. The mounting surface 21 is formed on the positive side in the z-axis direction of the focus ring substrate 20. The chuck electrode 22 is made of a conductive material. The chuck electrode 22 is connected to an external power supply via an electrode terminal (not shown). When power is supplied from an external power supply, the chuck electrode 22 generates an electrostatic attraction force capable of adsorbing and holding the focus ring FR to the mounting surface 21. In addition to the chuck electrode 22, the focus ring substrate 20 may also have high-frequency electrodes or heater electrodes.

[0023] In the holding device 1 of this embodiment, the inner circumference 20a of the focus ring base material 20 has a first chamfered portion 23 on the side opposite to the side joined to the base 30, as shown in Figures 2 and 3. The first chamfered portion 23 is formed by chamfering the corner of the inner circumference 20a of the focus ring base material 20 that is opposite to the side joined to the base 30. The first chamfered portion 23 is formed around the entire circumference of the inner circumference 20a of the focus ring base material 20.

[0024] Figure 4 is an enlarged view of part B in Figure 3. In this embodiment, the holding device 1 satisfies the following equation (1) in a cross-section including the central axis C1 of the holding device 1 as shown in Figure 2, where the thickness of the focus ring substrate 20 in the stacking direction (z-axis direction) of the substrate material 10 and the focus ring substrate 20 and the base 30 is thickness D, and the length of the first chamfered portion 23 is length L23. 0.2 ≤ L23 / D ≤ 1.4 ···(1)

[0025] The base 30 is a sintered body mainly composed of silicon carbide and has a substantially disc shape. Here, "main component" means the component with the highest proportion. The material forming the base 30 is not limited to a material mainly composed of silicon carbide, but may also be made of aluminum (Al), titanium (Ti), molybdenum (Mo), tungsten (W), alloys thereof, SUS, composites of metals and ceramics such as Al-SiC, or materials mainly composed of ceramics such as aluminum nitride (AlN) or alumina (Al2O3). The base 30 has a first bonding surface 31 to which the substrate material 10 for the circuit board is joined, a second bonding surface 32 to which the substrate material 20 for the focus ring is joined, and an intermediate portion 33 located between the first bonding surface 31 and the second bonding surface 32.

[0026] The first bonding surface 31 is a circular surface formed in the center of the base 30, including the center of the base 30, when the base 30 is viewed from the z-axis direction. As shown in Figures 2 and 3, when the mounting surface 11 of the substrate material 10 is located on the positive side of the z-axis direction of the holding device 1, the first bonding surface 31 is located on the most positive side of the z-axis direction of the base 30. The substrate material 10 and the first bonding surface 31 are joined by a first bonding portion 31a, which is a metal bonding material mainly composed of indium. Note that the first bonding portion 31a is not limited to a metal bonding material mainly composed of indium, but may also be a silicone-based organic adhesive, a brazing material containing hard or soft brazing materials, an inorganic bonding material, or a metal bonding material containing metals other than indium, such as gold or silver.

[0027] The second bonding surface 32 is an annular surface formed on the outer periphery of the first bonding surface 31 when the base 30 is viewed from the z-axis direction. As shown in Figures 2 and 3, when the mounting surface 11 of the substrate material 10 is located on the positive side of the z-axis direction of the holding device 1, the second bonding surface 32 is located on the negative side of the z-axis direction than the first bonding surface 31. The focus ring material 20 and the second bonding surface 32 are joined by a second bonding portion 32a, which is a metal bonding material mainly composed of indium. Note that the second bonding portion 32a is not limited to a metal bonding material mainly composed of indium, but may also be a silicone-based organic adhesive, a brazing material containing hard or soft brazing materials, an inorganic bonding material, or a metal bonding material containing metals other than indium, such as gold or silver.

[0028] The intermediate portion 33 is a so-called stepped portion formed so as to cause the positions of the first joining surface 31 and the second joining surface 32 to differ in the z-axis direction. The intermediate portion 33 in this embodiment has a first intermediate portion 331 and a second intermediate portion 332 (see Figure 3). The first intermediate portion 331 is a part of the portion of the base 30 that connects the first joining surface 31 and the second joining surface 32, and is formed so as shown in Figure 3, it moves away from the central axis C1 of the holding device 1 and toward the negative z-axis direction as it moves from the first joining surface 31 side toward the second joining surface 32 side. In a cross-section including the central axis C1 of the holding device 1, the length L33 of the first intermediate portion 331 is 1 mm or more (see Figure 4). The second intermediate portion 332 is the portion of the intermediate portion 33 toward the second joining surface 32, and is formed in a concave shape as shown in Figure 3.

[0029] In the holding device 1 of this embodiment, in a cross-section including the central axis C1 of the holding device 1 as shown in Figure 4, the angle θ1 formed by the direction of the normal V33 of the intermediate portion 33 and the direction of the first normal V23 of the first chamfered portion 23 is 90 degrees or less, and the angle θ2 formed by the direction of the normal V33 of the intermediate portion 33 and the direction of the second normal V13 of the second chamfered portion 13 is 90 degrees or less. Here, the normal V33 of the intermediate portion 33 refers to the normal of the first intermediate portion 331, which is represented by a straight line in the cross-section shown in Figure 4. The angle formed by the directions of the two normals refers to the angle between the directions to which each of the two normals is pointing. In the holding device 1, both angles θ1 and θ2 are 90 degrees.

[0030] The base 30 has a refrigerant channel 34 formed inside through which the refrigerant flows. The refrigerant flowing through the refrigerant channel 34 cools the substrate material 10 for the substrate and the substrate material 20 for the focus ring that are joined to the base 30, as well as the substrate W and focus ring FR that are placed on the mounting surfaces 11 and 21, via the base 30.

[0031] The insulating portion 41 is formed of ceramics and is placed in the gap formed between the substrate material 10 and the focus ring material 20, covering the intermediate portion 33. As shown in Figure 4, the insulating portion 41 is positioned between the substrate material 10 and the focus ring material 20, and is formed to connect to each of them. In this embodiment, the insulating portion 41 is formed by ceramic spraying. As a result, the ceramics forming the insulating portion 41 have different properties from the ceramics forming the substrate material 10 and the ceramics forming the focus ring material 20. In this embodiment, the porosity of the ceramics forming the insulating portion 41 is greater than the porosity of the ceramics forming the substrate material 10 and the porosity of the ceramics forming the focus ring material 20. Specifically, the porosity of the ceramics forming the insulating portion 41 is 3% to 10%, while the porosity of the ceramics forming the substrate material 10 and the porosity of the ceramics forming the focus ring material 20 are both 1% or less. Furthermore, the thermal conductivity of the ceramics forming the insulating portion 41 is lower than that of the ceramics forming the substrate material 10 and the ceramics forming the focus ring material 20. Specifically, the thermal conductivity of the ceramics forming the insulating portion 41 is 3 to 9 W / (m·K), while the thermal conductivity of the ceramics forming the substrate material 10 is 10 to 180 W / (m·K), and the thermal conductivity of the ceramics forming the focus ring material 20 is 10 to 180 W / (m·K).

[0032] As shown in Figures 3 and 4, the insulating portion 41 has a first insulating portion 411 and a second insulating portion 412. The first insulating portion 411 is mainly the portion surrounded by the first intermediate portion 331, the second chamfered portion 13 of the substrate material 10, and the first chamfered portion 23 of the focus ring material 20. The first insulating portion 411 is connected to the substrate material 10 and the focus ring material 20, respectively. The second insulating portion 412 is located in the negative z-axis direction relative to the first insulating portion 411 and is positioned further back than the first insulating portion 411. The second insulating portion 412 is the portion surrounded by the second intermediate portion 332 and the focus ring material 20.

[0033] Next, the manufacturing method of the holding device 1 of this embodiment will be described. The holding device 1 is manufactured by separately manufacturing the substrate material 10 for the substrate, the substrate material 20 for the focus ring, and the base 30, joining the substrate material 10 for the substrate and the substrate material 20 for the focus ring to the base 30, and then forming an insulating portion 41 between the substrate material 10 for the substrate and the substrate material 20 for the focus ring.

[0034] In the manufacturing method of the holding device 1, first, a substrate 10 for the substrate, a substrate 20 for the focus ring, and a base 30 are prepared (preparation step). In the production of the substrate 10 for the substrate, first, a slurry for green sheets containing aluminum nitride powder is formed into a sheet using a casting device, and the resulting molded product is dried to produce multiple green sheets. Next, a portion that will become the chuck electrode 12 is printed on a specific green sheet from among the multiple green sheets using a metallizing paste, for example, using a screen printing device. Next, a laminate of green sheets is produced by stacking multiple green sheets, including the specific green sheet on which the metallizing paste has been printed, and then fired. The substrate 10 for the substrate is produced by processing the portion that will become the second chamfer 13 of the fired laminate of green sheets. In the production of the substrate 20 for the focus ring, similar to the production of the substrate 10 for the substrate, first, multiple green sheets are produced using a slurry for green sheets containing aluminum nitride powder, and a portion that will become the chuck electrode 22 is printed on a specific green sheet from among the multiple green sheets using a metallizing paste. Next, a laminate of green sheets is created by stacking multiple green sheets, including a specific green sheet printed with metallized paste. After processing the portion that will become the first chamfered portion 23, the focus ring substrate 20 is produced by firing. However, the manufacturing method of the substrate 10 and the focus ring substrate 20 are not limited to these. For example, a binder is added to a raw material powder containing additives such as yttrium oxide to aluminum nitride powder to granulate powder, and the granulate powder is filled into a carbon mold and pressed into a flat plate shape. A foil-shaped or mesh-shaped planar electrode is placed on the flat plate-shaped molded body, and granulate powder is further filled onto the placed planar electrode. Then, the body is fired while applying pressure in a uniaxial direction with a carbon punch (powder hot press method). The substrate 10 and the focus ring substrate 20 can also be produced by such a powder hot press method.

[0035] In the production of the base 30, a binder is added to a raw material powder containing silicon carbide and other additives such as boron carbide (B4C) to granule powder. Using the granulated granule powder, an ingot of a molded body is produced by hydrostatic molding, and then multiple molded bodies that will become the base 30 are produced from the ingot of the molded body. The multiple molded bodies are fired to become multiple sintered bodies, and then a groove corresponding to the refrigerant channel 34 is machined into a specific sintered body. The base 30 is produced by joining a specific sintered body to another sintered body so that the groove corresponding to the refrigerant channel 34 machined into the specific sintered body is covered by another sintered body. If necessary, final shaping may be performed after joining the specific sintered body to another sintered body. Note that the manufacturing method of the base 30 is not limited to this. For example, a slurry for green sheets containing silicon carbide powder is molded into a sheet shape using a casting device, and multiple green sheets are produced by drying the resulting molded products. Next, a groove corresponding to the refrigerant flow path 34 is machined into a specific green sheet from among several green sheets. Then, the base 30 is manufactured by firing a laminate of green sheets, which includes the specific green sheet with the machined groove.

[0036] Figure 5 is the first diagram illustrating the manufacturing method of the holding device 1 of this embodiment. In the manufacturing method of the holding device 1, following the preparation step, the substrate material 10 for the substrate and the focus ring material 20 are joined to the base 30 (joining step). Specifically, a metal bonding material mainly composed of indium is applied to the first bonding surface 31 and the second bonding surface 32 of the base 30. Next, the substrate material 10 is joined to the base 30 by the metal bonding material applied to the first bonding surface 31, and the focus ring material 20 is joined to the base 30 by the metal bonding material applied to the second bonding surface 32. Figure 5 shows the gap Sp between the substrate material 10 and the focus ring material 20 that is formed when the substrate material 10 and the focus ring material 20 are joined to the base 30.

[0037] Figure 6 is a second diagram illustrating the manufacturing method of the holding device 1 of this embodiment. In the manufacturing method of the holding device 1, following the joining process, an insulating portion 41 is formed in the gap Sp formed between the substrate material 10 and the focus ring material 20 using ceramic spraying (insulating portion formation process). Specifically, molten ceramics Cm are supplied to the intermediate portion 33 from between the substrate material 10 and the focus ring material 20 using a thermal spray gun G as shown in Figure 6. The injection direction of the molten ceramics Cm ejected from the thermal spray gun G is preferably at an angle of ±45 degrees around the normal V33 of the intermediate portion 33, as viewed from the intermediate portion 33 where the molten ceramics Cm is deposited. In the manufacturing method of the holding device 1 of this embodiment, the positional relationship between the intermediate portion 33 and the first chamfered portion 23 and the second chamfered portion 13 is represented by the angles θ1 and θ2 shown in Figure 4, so the entrance to the gap Sp is relatively wide. This makes it easier to supply molten ceramics Cm to the intermediate portion 33.

[0038] The molten ceramics supplied to the intermediate section 33 are deposited on the intermediate section 33, forming a ceramic spray coating that serves as an insulating section 41. After the ceramic spray coating is formed, the surface of the ceramic spray coating may be processed to shape the outer form of the insulating section 41. At this time, by processing the surface roughness Ra of the surface 41a of the insulating section 41 to, for example, 1 μm or less, it is possible to suppress the adhesion of film deposition residue when the holding device 1 is used in the film deposition process on the substrate W, and to suppress the detachment of ceramic particles from the ceramic spray coating. In this way, the insulating section 41 covering the intermediate section 33 is formed, and the holding device 1 is manufactured. Note that the method of forming the insulating section 41 is not limited to this. In addition to the method using a thermal spray gun G, a directional film deposition method such as film deposition by aerosol deposition may also be used. Furthermore, the second insulating portion 412 of the insulating portion 41 may be formed not by using a thermal spray gun G, but by filling the portion surrounded by the second intermediate portion 332 and the focus ring substrate 20 with a heat-resistant inorganic bonding material or organic adhesive. Moreover, the portion corresponding to the second insulating portion 412 does not need to be formed if the first insulating portion 411 is connected to the substrate 10 and the focus ring substrate 20 respectively, and the intermediate portion 33 is completely covered by the first insulating portion 411.

[0039] As described above, according to the holding device 1 of this embodiment, the base 30 has an intermediate portion 33 located between a first bonding surface 31 to which the substrate material 10 is bonded and a second bonding surface 32 to which the focus ring material 20 is bonded. The intermediate portion 33 is made of ceramics and is covered by an insulating portion 41 which is placed in the gap formed between the substrate material 10 and the focus ring material 20. As a result, for example, even if the holding device 1 is used in a process that utilizes plasma, the intermediate portion 33 will not be exposed to the environment in which the plasma is formed, so the plasma sheath will not change easily even if the holding device 1 is used continuously. Therefore, the plasma can be formed continuously and stably.

[0040] Furthermore, according to the holding device 1 of this embodiment, since the intermediate portion 33 is covered by the insulating portion 41, it is not exposed to process gas used in, for example, the plasma etching process using the holding device 1, and thus damage to the intermediate portion 33 by process gas can be suppressed. As a result, the generation of foreign matter and contamination originating from the intermediate portion 33 can be suppressed, and the quality of the substrate held by the holding device 1 can be improved.

[0041] Furthermore, according to the holding device 1 of this embodiment, the porosity of the ceramics forming the insulating portion 41 is greater than that of the ceramics forming the substrate material 10 and the ceramics forming the focus ring material 20. This difference in porosity is due to the insulating portion 41 being formed to fill the gap between the substrate material 10 and the focus ring material 20. In other words, the insulating portion 41 is formed according to the shape of the gap formed between the substrate material 10 and the focus ring material 20, and the exposure of the intermediate portion 33 can be further suppressed. In addition, the insulating portion 41, which has a relatively large porosity, has relatively high adhesion to the substrate material 10 and the focus ring material 20, respectively. As a result, changes in the plasma sheath can be further suppressed, and the plasma can be formed more continuously and stably.

[0042] Furthermore, according to the holding device 1 of this embodiment, the thermal conductivity of the ceramics forming the insulating portion 41 is smaller than that of the ceramics forming the substrate material 10 and the ceramics forming the focus ring material 20. This difference in thermal conductivity is due to the fact that the insulating portion 41, unlike the substrate material 10 and the focus ring material 20, is formed to fill the gap formed between the substrate material 10 and the focus ring material 20. In other words, the insulating portion 41 is formed according to the shape of the gap formed between the substrate material 10 and the focus ring material 20, and the exposure of the intermediate portion 33 can be further suppressed. In addition, the insulating portion 41, which has relatively low thermal conductivity, can suppress heat transfer between the substrate material 10 and the focus ring material 20. As a result, changes in the plasma sheath can be further suppressed, and the plasma can be formed more continuously and stably.

[0043] Furthermore, according to the holding device 1 of this embodiment, the base 30 has a step formed between the first bonding surface 31 and the second bonding surface 32 by the intermediate portion 33, and the substrate material 10 for the substrate that is bonded to the first bonding surface 31 and the focus ring material 20 that is bonded to the second bonding surface 32 are positioned at offset locations in the direction along the central axis C1 of the holding device 1. In addition, since the intermediate portion 33 is formed to move away from the central axis C1 of the holding device 1 from the first bonding surface 31 side toward the second bonding surface 32 side, the intermediate portion 33 is easily visible from between the substrate material 10 and the focus ring material 20. This makes it easier to form an insulating portion 41 that covers the intermediate portion 33, and thus further suppresses the exposure of the intermediate portion 33. Therefore, plasma can be formed more continuously and stably.

[0044] Furthermore, according to the holding device 1 of this embodiment, the base 30 has an intermediate portion 33 with a length of 1 mm or more in a cross-section including the central axis C1 of the holding device 1. As a result, the insulating portion 41 that is formed to cover the intermediate portion 33 is more easily formed on the intermediate portion 33, so that the exposure of the intermediate portion 33 can be further suppressed. Therefore, the plasma can be formed more continuously and stably.

[0045] Furthermore, according to the holding device 1 of this embodiment, the inner circumference 20a of the focus ring base material 20 has a first chamfered portion 23 on the side opposite to the side joined to the base 30. The first chamfered portion 23 is formed such that, in a cross-section including the central axis C1 of the holding device 1, the relationship between the thickness D of the focus ring base material 20 and the length L of the first chamfered portion 23 satisfies equation (1). As a result, when forming the insulating portion 41 to cover the intermediate portion 33, the material forming the insulating portion 41 can easily pass between the substrate base material 10 and the focus ring base material 20, making it easier to form the insulating portion 41 on the intermediate portion 33. Therefore, exposure of the intermediate portion 33 can be further suppressed, and the plasma can be formed more continuously and stably.

[0046] Furthermore, according to the holding device 1 of this embodiment, the inner circumference 20a of the focus ring substrate 20 has a first chamfered portion 23 on the side opposite to the side joined to the base 30, and the outer circumference 10a of the substrate 10 has a second chamfered portion 13 on the side joined to the base 30. The angle θ1 between the direction of the normal V33 of the intermediate portion 33 and the direction of the first normal V23 of the first chamfered portion 23, and the angle θ2 between the direction of the normal V33 of the intermediate portion 33 and the direction of the second normal V13 of the second chamfered portion 13 are both 90 degrees or less. As a result, when forming an insulating portion 41 to cover the intermediate portion 33, the material forming the insulating portion 41 can pass more easily between the substrate 10 and the focus ring substrate 20, making it easier to form the insulating portion 41 on the intermediate portion 33. Therefore, the exposure of the intermediate portion 33 can be further suppressed, and the plasma can be formed more continuously and stably.

[0047] Furthermore, according to the manufacturing method of the holding device 1 of this embodiment, after joining the substrate material 10 for the substrate and the focus ring material 20 to the base 30 in the joining process, an insulating part 41 covering the intermediate part 33 of the base 30 is formed using ceramic thermal spraying in the insulating part formation process. This makes it possible to form an insulating part 41 covering the intermediate part 33 on the intermediate part 33. Therefore, even if the holding device 1 is used continuously in processes using plasma, the plasma sheath is less likely to change, and thus it is possible to manufacture a holding device 1 that can continuously and stably form plasma.

[0048] Furthermore, according to the manufacturing method of the holding device 1 of this embodiment, in the preparation step, a base 30 having an intermediate portion 33 with a length of 1 mm or more in a cross-section including the central axis C1 of the holding device 1 is prepared. This makes it easier for the insulating portion 41, which is formed to cover the intermediate portion 33, to be formed on the intermediate portion 33 in the insulating portion formation step. Also, in the preparation step, a focus ring base material 20 having a first chamfered portion 23 on the side of the inner circumference 20a opposite to the side joined to the base 30, and a substrate base material 10 having a second chamfered portion 13 on the side of the outer circumference 10a joined to the base 30 are prepared. In the bonding process, when the substrate material 10 and the focus ring material 20 are bonded to the base 30, the angle θ1 formed by the direction of the normal V33 of the intermediate portion 33 and the direction of the first normal V23 of the first chamfered portion 23, and the angle θ2 formed by the direction of the normal V33 of the intermediate portion 33 and the direction of the second normal V13 of the second chamfered portion 13, are both 90 degrees or less. As a result, the entrance to the gap Sp formed between the substrate material 10 and the focus ring material 20 becomes relatively wide, and it is easier to supply molten ceramics to the intermediate portion 33, so that an insulating portion 41 covering the intermediate portion 33 can be formed on the intermediate portion 33 relatively easily. Therefore, since the exposure of the intermediate portion 33 is further suppressed, it is possible to manufacture a holding device 1 that can form plasma more continuously and stably.

[0049] <Second Embodiment> Figure 7 is an enlarged cross-sectional view of the holding device of the second embodiment. Compared to the holding device 1 of the first embodiment (Figure 3), the holding device 2 of the second embodiment has a different relationship between the position of the mounting surface 11 of the substrate material 10 and the position of the mounting surface 21 of the focus ring material 20.

[0050] The holding device 2 of this embodiment is an electrostatic chuck that holds the substrate W by electrostatic attraction. The holding device 2 comprises a substrate base material 10, a focus ring base material 20, a base 30, and an insulating part 42. In the holding device 2, as shown in Figure 7, the mounting surface 11 of the substrate base material 10 and the mounting surface 21 of the focus ring base material 20 are located at the same position in the z-axis direction. That is, the mounting surface 11 and the mounting surface 21 are located on the same plane.

[0051] The insulating portion 42 is formed of ceramics and is positioned in the gap formed between the substrate material 10 and the focus ring material 20, covering the intermediate portion 33. The insulating portion 42 has a first insulating portion 421 and a second insulating portion 422. The first insulating portion 421 is mainly the portion surrounded by the intermediate portion 33, the second chamfered portion 13 of the substrate material 10, and the first chamfered portion 23 of the focus ring material 20. The first insulating portion 421 is connected to both the substrate material 10 and the focus ring material 20. The second insulating portion 422 is located in the negative z-axis direction relative to the first insulating portion 421 and is the portion surrounded by the intermediate portion 33 and the inner circumference 20a of the focus ring material 20. The insulating portion 42 is formed by ceramic thermal spraying.

[0052] Figure 8 is an enlarged view of section C in Figure 7. In the holding device 2, in a cross-section including the central axis of the holding device 2 as shown in Figure 8, the angle θ1 between the direction of the normal V33 of the intermediate section 33 and the direction of the first normal V23 of the first chamfered section 23 is 90 degrees or less, and the angle θ2 between the direction of the normal V33 of the intermediate section 33 and the direction of the second normal V13 of the second chamfered section 13 is 90 degrees or less. This makes it easier to deposit molten ceramics onto the intermediate section 33 when forming the insulating section 42 by ceramic spraying.

[0053] As described above, in the holding device 2 of this embodiment, the intermediate portion 33 located between the first bonding surface 31 to which the substrate material 10 is bonded and the second bonding surface 32 to which the focus ring material 20 is bonded in the base 30 is made of ceramics and is covered by an insulating portion 41 that is placed in the gap formed between the substrate material 10 and the focus ring material 20. As a result, even if the holding device 2 is used in a process that utilizes plasma, the intermediate portion 33 is not exposed to the environment in which the plasma is formed, so the plasma sheath is less likely to change even if the holding device 2 is used continuously. Therefore, the plasma can be formed continuously and stably.

[0054] Furthermore, according to the manufacturing method of the holding device 2 of this embodiment, the positional relationship between the intermediate portion 33 and the first chamfered portion 23 and the second chamfered portion 13 is represented by the angles θ1 and θ2 shown in Figure 8, so the opening of the gap formed between the substrate material 10 and the focus ring material 20 is relatively wide. As a result, it is easy to supply molten ceramics to the intermediate portion 33, and an insulating portion 42 covering the intermediate portion 33 can be formed on the intermediate portion 33 relatively easily. Therefore, even if the holding device 2 is used continuously in a process using plasma, the plasma sheath is less likely to change, and a holding device 2 that can continuously and stably form plasma can be manufactured.

[0055] <Third Embodiment> Figure 9 is an enlarged cross-sectional view of the holding device of the third embodiment. Compared to the holding device 1 of the first embodiment (Figure 3), the holding device 3 of the third embodiment has a different positional relationship between the substrate material 10 for the substrate and the substrate material 20 for the focus ring.

[0056] The holding device 3 of this embodiment is an electrostatic chuck that holds the substrate W by electrostatic attraction. The holding device 3 comprises a substrate base material 10, a focus ring base material 20, a base 30, and an insulating part 43. In the holding device 3, as shown in Figure 9, the outer circumference 10a of the substrate base material 10 and the inner circumference 20a of the focus ring base material 20 overlap in the z-axis direction.

[0057] The insulating portion 43 is made of ceramics and is positioned in the gap formed between the substrate material 10 and the focus ring material 20, covering the intermediate portion 33. The insulating portion 43 has a first insulating portion 431 and a second insulating portion 432. The first insulating portion 431 is mainly the portion surrounded by the intermediate portion 33, the second chamfered portion 13 of the substrate material 10, and the first chamfered portion 23 of the focus ring material 20, and covers the first intermediate portion 331. The first insulating portion 431 is connected to the substrate material 10 and the focus ring material 20, respectively. The second insulating portion 432 is located in the negative z-axis direction relative to the first insulating portion 421 and is the portion surrounded by the intermediate portion 33 and the inner circumference portion 20a of the focus ring material 20. The second insulating portion 432 covers the concave second intermediate portion 332.

[0058] Figure 10 is an enlarged view of section D in Figure 9. In the holding device 3 of this embodiment, in a cross-section including the central axis of the holding device 3 as shown in Figure 10, the angle θ2 between the direction of the normal V33 of the intermediate section 33 (first intermediate section 331) and the direction of the second normal V13 of the second chamfered section 13 is 90 degrees or less, while the angle θ1 between the direction of the normal V33 of the intermediate section 33 and the direction of the first normal V23 of the first chamfered section 23 is greater than 90 degrees. When the relationship between the intermediate section 33, the first chamfered section 23, and the second chamfered section 13 is such that, for example, molten ceramics can be easily deposited on the intermediate section 33 by supplying molten ceramics from a direction along the second chamfered section 13. This makes it possible to form the first insulating section 431 using a thermal spray gun. On the other hand, since the second insulating portion 432 is located in a recessed position within the gap formed between the substrate material 10 for the substrate and the substrate material 20 for the focus ring, it is preferable to form it by filling it with a heat-resistant inorganic bonding material or an organic adhesive.

[0059] As described above, in the holding device 3 of this embodiment, the intermediate portion 33 located between the first bonding surface 31 to which the substrate material 10 is bonded and the second bonding surface 32 to which the focus ring material 20 is bonded in the base 30 is made of ceramics and is covered by an insulating portion 43 that is placed in the gap formed between the substrate material 10 and the focus ring material 20. As a result, even if the holding device 3 is used in a process that utilizes plasma, the intermediate portion 33 is not exposed to the environment in which the plasma is formed, so the plasma sheath is less likely to change even if the holding device 3 is used continuously. Therefore, the plasma can be formed continuously and stably.

[0060] Furthermore, according to the manufacturing method of the holding device 3 of this embodiment, the positional relationship between the intermediate portion 33 and the first chamfered portion 23 and the second chamfered portion 13 is represented by the angles θ1 and θ2 shown in Figure 10, so the opening of the gap formed between the substrate material 10 and the focus ring material 20 is relatively wide. As a result, it is easy to supply molten ceramics to the intermediate portion 33, and an insulating portion 43 covering the intermediate portion 33 can be formed on the intermediate portion 33 relatively easily. Therefore, even if the holding device 3 is used continuously in a process using plasma, the plasma sheath is less likely to change, and a holding device 3 that can continuously and stably form plasma can be manufactured.

[0061] <Fourth Embodiment> Figure 11 is an enlarged cross-sectional view of the holding device of the fourth embodiment. Compared to the holding device 1 of the first embodiment (Figure 3), the holding device 4 of the fourth embodiment has a different relationship between the position of the first joining surface 31 and the position of the second joining surface 32 on the base 30.

[0062] The holding device 4 of this embodiment is an electrostatic chuck that holds the substrate W by electrostatic attraction. The holding device 4 comprises a substrate material 10, a focus ring material 20, a base 30, and an insulating part 44. In the holding device 4, as shown in Figure 11, the first bonding surface 31 and the second bonding surface 32 of the base 30 are located at the same position in the z-axis direction. That is, the first bonding surface 31 and the second bonding surface 32 are located on the same plane.

[0063] The insulating portion 44 is formed of ceramics and is positioned in the gap formed between the substrate material 10 and the focus ring material 20, covering the intermediate portion 33. The insulating portion 44 has a first insulating portion 441 and a second insulating portion 442. The first insulating portion 441 is mainly the portion surrounded by the intermediate portion 33, the second chamfered portion 13 of the substrate material 10, and the first chamfered portion 23 of the focus ring material 20. The first insulating portion 441 is connected to both the substrate material 10 and the focus ring material 20. The second insulating portion 442 is the portion surrounded by the intermediate portion 33 and the inner circumference portion 20a of the focus ring material 20. The insulating portion 44 is formed by ceramic thermal spraying.

[0064] Figure 12 is an enlarged view of section E in Figure 11. In the holding device 4, in a cross-section including the central axis of the holding device 4 as shown in Figure 12, the angle θ1 between the direction of the normal V33 of the intermediate section 33 and the direction of the first normal V23 of the first chamfered section 23 is 90 degrees or less. On the other hand, the angle θ2 between the direction of the normal V33 of the intermediate section 33 and the direction of the second normal V13 of the second chamfered section 13 is greater than 90 degrees. When the relationship between the intermediate section 33, the first chamfered section 23 and the second chamfered section 13 is as described above, for example, molten ceramics can be easily deposited on the intermediate section 33 by supplying molten ceramics from the direction along the normal V33 and the direction along the first chamfered section 23. This makes it possible to form an insulating section 44 using a thermal spray gun.

[0065] As described above, in the holding device 4 of this embodiment, the intermediate portion 33 located between the first bonding surface 31 to which the substrate material 10 is bonded and the second bonding surface 32 to which the focus ring material 20 is bonded in the base 30 is made of ceramics and is covered by an insulating portion 44 that is placed in the gap formed between the substrate material 10 and the focus ring material 20. As a result, even if the holding device 4 is used in a process that utilizes plasma, the intermediate portion 33 is not exposed to the environment in which the plasma is formed, so the plasma sheath is less likely to change even if the holding device 4 is used continuously. Therefore, the plasma can be formed continuously and stably.

[0066] Furthermore, according to the manufacturing method of the holding device 4 of this embodiment, the positional relationship between the intermediate portion 33 and the first chamfered portion 23 and the second chamfered portion 13 is represented by the angles θ1 and θ2 shown in Figure 12, so the opening of the gap formed between the substrate material 10 and the focus ring material 20 is relatively wide. As a result, it is easy to supply molten ceramics to the intermediate portion 33, and an insulating portion 44 covering the intermediate portion 33 can be formed on the intermediate portion 33 relatively easily. Therefore, even if the holding device 4 is used continuously in a process using plasma, the plasma sheath is less likely to change, and a holding device 4 that can continuously and stably form plasma can be manufactured.

[0067] <Fifth Embodiment> Figure 13 is an enlarged cross-sectional view of the holding device of the fifth embodiment. Compared to the holding device 1 of the first embodiment (Figure 3), the holding device 5 of the fifth embodiment differs in the shape of the outer peripheral portion 10a of the substrate material 10 and the inner peripheral portion 20a of the focus ring material 20.

[0068] The holding device 5 of this embodiment is an electrostatic chuck that holds the substrate W by electrostatic attraction. The holding device 5 comprises a substrate base material 10, a focus ring base material 20, a base 30, and an insulating part 45. In the holding device 5, as shown in Figure 13, the entire outer circumference 10a of the substrate base material 10 is a second chamfered portion 13, and the entire inner circumference 20a of the focus ring base material 20 is a first chamfered portion 23.

[0069] The insulating portion 45 is formed of ceramics and is positioned in the gap formed between the substrate material 10 and the focus ring material 20, covering the intermediate portion 33. The insulating portion 45 is the portion surrounded by the intermediate portion 33 of the base 30, the second chamfered portion 13 of the substrate material 10, and the first chamfered portion 23 of the focus ring material 20. The insulating portion 45 is connected to both the substrate material 10 and the focus ring material 20. The insulating portion 45 is formed by ceramic thermal spraying.

[0070] Figure 14 is an enlarged view of section F in Figure 13. In the holding device 5, as shown in Figure 14, in a cross-section including the central axis of the holding device 5, the angle θ1 between the direction of the normal V33 of the intermediate section 33 and the direction of the first normal V23 of the first chamfered section 23 is 90 degrees or less, and the angle θ2 between the direction of the normal V33 of the intermediate section 33 and the direction of the second normal V13 of the second chamfered section 13 is 90 degrees or less. This makes it easier to deposit molten ceramics onto the intermediate section 33 when forming the insulating section 45 by ceramic spraying. In the holding device 5, as shown in Figure 14, the entrance to the gap between the substrate material 10 for the substrate and the substrate material 20 for the focus ring is relatively large. This makes it easier to form the entire insulating section 45 by ceramic spraying.

[0071] As described above, in the holding device 5 of this embodiment, the intermediate portion 33 located between the first bonding surface 31 to which the substrate material 10 is bonded and the second bonding surface 32 to which the focus ring material 20 is bonded in the base 30 is made of ceramics and is covered by an insulating portion 45 that is placed in the gap formed between the substrate material 10 and the focus ring material 20. As a result, even if the holding device 5 is used in a process that utilizes plasma, the intermediate portion 33 is not exposed to the environment in which the plasma is formed, so the plasma sheath is less likely to change even if the holding device 5 is used continuously. Therefore, the plasma can be formed continuously and stably.

[0072] Furthermore, according to the manufacturing method of the holding device 5 of this embodiment, the positional relationship between the intermediate portion 33 and the first chamfered portion 23 and the second chamfered portion 13 is represented by the angles θ1 and θ2 shown in Figure 14, so the opening of the gap formed between the substrate material 10 and the focus ring material 20 is relatively wide. As a result, it is easy to supply molten ceramics to the intermediate portion 33, and an insulating portion 45 covering the intermediate portion 33 can be formed on the intermediate portion 33 relatively easily. Therefore, even if the holding device 5 is used continuously in a process using plasma, the plasma sheath is less likely to change, and a holding device 5 that can continuously and stably form plasma can be manufactured.

[0073] <Modified form of this embodiment> The present invention is not limited to the embodiments described above, and can be implemented in various forms without departing from its spirit, for example, the following modifications are also possible.

[0074] [Example 1] In the above-described embodiment, the holding device is an electrostatic chuck that attracts and holds the substrate W by electrostatic force. The technical field to which the holding device is applied is not limited to this. It can also be applied to technical fields where it is necessary to maintain a state in which an object to be held, including a substrate, is held.

[0075] [Differentiation 2] In the above-described embodiment, the holding device comprises a substrate material 10 for the substrate, a substrate material 20 for the focus ring, a base 30, and an insulating part. However, the configuration of the holding device is not limited to this. For example, a layer different from the first joint portion 31a may be arranged between the substrate material 10 and the base 30, or a layer different from the second joint portion 32a may be arranged between the substrate material 20 for the focus ring and the base 30. The substrate material 10, the substrate material 20 for the focus ring, and the base 30 are each described as a single plate-shaped member as shown in Figure 2, etc., but they may be formed by laminating multiple plate-shaped members.

[0076] [Difference 3] In the above-described embodiment, the porosity of the ceramics forming the insulating portion is assumed to be greater than the porosity of the ceramics forming the substrate material 10 and the porosity of the ceramics forming the focus ring material 20, and the thermal conductivity of the ceramics forming the insulating portion is assumed to be less than the thermal conductivity of the ceramics forming the substrate material 10 and the thermal conductivity of the ceramics forming the focus ring material 20. However, the relationship between the properties of the ceramics forming the insulating portion, the properties of the ceramics forming the substrate material 10, and the properties of the ceramics forming the focus ring material 20 is not limited to this. The properties may be the same.

[0077] [Differentiation Example 4] In the above embodiment, the length of the intermediate portion in the cross-section including the central axis of the retaining device was set to 1 mm or more. The length of the intermediate portion is not limited to this, but a longer length makes it easier to form an insulating portion.

[0078] [Difference 5] In the above-described embodiment, the relationship between the thickness D of the focus ring base material 20 and the length L23 of the first chamfered portion 23 was assumed to satisfy equation (1). However, the relationship between the thickness D of the focus ring base material 20 and the length L23 of the first chamfered portion 23 is not limited to this. L23 / D may be less than 0.2 or greater than 1.4. When L23 / D is relatively small, the area where it is difficult to supply molten ceramics by the thermal spray gun increases, so a value of 0.2 or greater is desirable. When L23 / D is relatively small, the mounting surface 21 on which the focus ring FR is placed becomes smaller, so a value of 1.4 or greater is desirable.

[0079] [Modification 6] In the above-described embodiment, at least one of the angle θ1 formed by the direction of the normal V33 of the intermediate portion 33 and the direction of the first normal V23 of the first chamfered portion 23, and the angle θ2 formed by the direction of the normal V33 of the intermediate portion 33 and the direction of the second normal V13 of the second chamfered portion 13, was assumed to be 90 degrees or less. However, both angles θ1 and θ2 may be greater than 90 degrees. When both angles θ1 and θ2 are 90 degrees or less, as described in the fifth embodiment, for example, the entrance to the gap between the substrate material 10 and the focus ring material 20 becomes relatively larger as you move in the direction of the z-axis direction, making it easier to form the entire insulating portion by ceramic spraying.

[0080] [Difference 7] In the above-described embodiment, the substrate material 10 for the substrate has a second chamfered portion 13 on its outer peripheral portion 10a, and the substrate material 20 for the focus ring has a first chamfered portion 23 on its inner peripheral portion 20a. However, at least one of the substrate material 10 for the substrate and the substrate material 20 for the focus ring does not need to have a chamfered portion.

[0081] Figure 15 is a cross-sectional view of a first modified example of the holding device 1 of the first embodiment. In the holding device 1 shown in Figure 15, the outer peripheral portion 10a of the substrate material 10 does not have a chamfered portion and has an end face 10b that is formed along the z-axis direction. The first insulating portion 411 of the insulating portion 41 is connected to the substrate material 10 and the focus ring material 20, respectively. As a result, the intermediate portion 33 is covered by the insulating portion 41, which makes it difficult for the plasma sheath to change and suppresses damage to the intermediate portion 33 by process gas. Therefore, the generation of foreign matter and contamination originating from the intermediate portion 33 can be suppressed, and the plasma can be continuously and stably formed while improving the quality of the substrate.

[0082] Figure 16 is a cross-sectional view of a second modified example of the holding device 1 of the first embodiment. In the holding device 1 shown in Figure 16, the outer peripheral portion 10a of the substrate material 10 is not chamfered and has an end face 10b formed along the z-axis direction, and the inner peripheral portion 20a of the focus ring material 20 is not chamfered and has an end face 20b formed along the z-axis direction. The insulating portion 41 is connected to the substrate material 10 and the focus ring material 20, respectively. As a result, the intermediate portion 33 is covered by the insulating portion 41, which makes it difficult for the plasma sheath to change and suppresses damage to the intermediate portion 33 by process gas. Therefore, the generation of foreign matter and contamination originating from the intermediate portion 33 can be suppressed, and the plasma can be continuously and stably formed while improving the quality of the substrate.

[0083] The embodiments of this specification have been described above based on the embodiments and modifications described above. The embodiments described above are for the purpose of facilitating understanding of this specification and do not limit it. This specification may be modified and improved without departing from its spirit and the scope of the claims, and equivalents thereof are included in this specification. Furthermore, any technical features that are not described as essential in this specification may be deleted as appropriate.

[0084] <Application Example 1> A holding device for holding a substrate, A substrate base material formed in the shape of a plate from ceramics and having a mounting surface on which the substrate is placed, A focus ring substrate formed in a ring shape from ceramics and positioned on the outer periphery of the substrate material, A base having a first bonding surface to which the substrate material for the substrate is bonded, a second bonding surface to which the substrate material for the focus ring is bonded, and an intermediate portion located between the first bonding surface and the second bonding surface, It is characterized by comprising an insulating portion formed of ceramics, which is disposed in the gap formed between the substrate material for the substrate and the substrate material for the focus ring and covers the intermediate portion, holding device. <Application Example 2> The holding device described in Application Example 1, The porosity of the ceramics forming the insulating portion is greater than the porosity of the ceramics forming the substrate material and the porosity of the ceramics forming the focus ring material. holding device. <Application Example 3> A holding device as described in Application Example 1 or Application Example 2, The thermal conductivity of the ceramics forming the insulating portion is smaller than that of the ceramics forming the substrate material for the substrate and the thermal conductivity of the ceramics forming the substrate material for the focus ring. holding device. <Application Example 4> A holding device described in any one of the examples from Application Example 1 to Application Example 3, The base has a step between the first joining surface and the second joining surface, formed by the intermediate portion. The intermediate portion is characterized in that it is formed so as to move away from the central axis of the holding device from the first joining surface side toward the second joining surface side. holding device. <Application Example 5> The holding device described in Application Example 4, In a cross-section including the central axis of the holding device, The length of the aforementioned intermediate portion is characterized by being 1 mm or more. holding device. <Application Example 6> A holding device described in any one of Application Examples 1 to 5, The inner circumference of the base material for the focus ring has a first chamfered portion on the side opposite to the side joined to the base, In a cross-section including the central axis of the holding device, In the stacking direction of the substrate material for the substrate and the substrate material for the focus ring and the base, if the thickness of the substrate material for the focus ring is D and the length of the first chamfered portion is L, then the following equation (1) is satisfied, holding device. 0.2 ≤ L / D ≤ ​​1.4 ···(1) <Application Example 7> A holding device described in any one of the examples from Application Example 1 to Application Example 6, The base has a step between the first joining surface and the second joining surface, formed by the intermediate portion. The intermediate portion is formed so as to move away from the central axis of the holding device from the first joining surface side toward the second joining surface side, The inner circumference of the base material for the focus ring has a first chamfered portion on the side opposite to the side joined to the base, The outer periphery of the substrate material has a second chamfered portion on the side that is joined to the base, In a cross-section including the central axis of the holding device, The angle between the direction of the normal to the intermediate portion and the direction of the first normal to the first chamfered portion is 90 degrees or less. The angle between the direction of the normal to the intermediate portion and the direction of the second normal to the second chamfered portion is 90 degrees or less. holding device. <Application Example 8> A substrate base material formed in the shape of a plate from ceramics and having a mounting surface on which a substrate is placed, A focus ring substrate formed in a ring shape from ceramics and positioned on the outer periphery of the substrate material, A base having a first bonding surface to which the substrate material for the substrate is bonded, a second bonding surface to which the substrate material for the focus ring is bonded, and an intermediate portion located between the first bonding surface and the second bonding surface, A method for manufacturing a holding device comprising an insulating portion formed of ceramics, which is disposed in the gap formed between the substrate material for the substrate and the substrate material for the focus ring and covers the intermediate portion, A preparation step of preparing the substrate for the substrate, the substrate for the focus ring, and the base, A bonding step of joining the substrate material for the substrate and the substrate material for the focus ring to the base, The invention is characterized by comprising an insulating portion forming step, after the bonding step, in which the insulating portion is formed in the gap between the substrate material for the substrate and the substrate material for the focus ring using ceramic thermal spraying, after the bonding step. A method for manufacturing a holding device. <Application Example 9> A method for manufacturing a holding device as described in Application Example 8, In the aforementioned preparation step, A focus ring base material having a first chamfered portion on its inner circumference, wherein in a cross-section including the central axis of the focus ring base material, the relationship between its own thickness D and the length L of the first chamfered portion is 0.2 ≤ L / D ≤ ​​1.4, The substrate material having a second chamfered portion on its outer periphery, A base is prepared having a step formed by the intermediate portion between the first joint surface and the second joint surface, the intermediate portion being formed so as to move away from the central axis of the base from the first joint surface side to the second joint surface side, and the length of the intermediate portion being 1 mm or more in a cross-section including the central axis of the base. In the aforementioned joining process, The focus ring substrate is positioned relative to the base such that the first chamfered portion is located on the side opposite to the side joined to the base, and in a cross-section including the central axis of the base, the angle between the direction of the normal to the intermediate portion and the direction of the first normal to the first chamfered portion is 90 degrees or less. The substrate material is positioned relative to the base such that the second chamfered portion is located on the side to be joined to the base, and in a cross-section including the central axis of the base, the angle between the direction of the normal to the intermediate portion and the direction of the second normal to the second chamfered portion is 90 degrees or less. The substrate material for the substrate and the substrate material for the focus ring are joined to the base, A method for manufacturing a holding device. [Explanation of symbols]

[0085] 1,2,3,4,5…holding device W... Circuit board 10...Base material for substrate 10a...Outer periphery 11… Mounting surface 13…Second chamfered section 20…Base material for focus ring 20a...Inner circumference 23...First chamfered section 30…Base 31…First joint surface 32…Second joint surface 33...Middle section 41, 42, 43, 44, 45... Insulation part V13, V23, V33... Normal vectors θ1, θ2…Angle

Claims

1. A holding device for holding a substrate, A substrate base material formed in the shape of a plate from ceramics and having a mounting surface on which the substrate is placed, A focus ring substrate formed in a ring shape from ceramics and positioned on the outer periphery of the substrate material, A base having a first bonding surface to which the substrate material for the substrate is bonded, a second bonding surface to which the focus ring material is bonded, and an intermediate portion located between the first bonding surface and the second bonding surface, It comprises an insulating portion formed of ceramics, which is disposed in the gap formed between the substrate material for the substrate and the substrate material for the focus ring and covers the intermediate portion, The base has a step formed by the intermediate portion between the first joining surface and the second joining surface. The outer periphery of the substrate material for the substrate, on the side that is joined to the base, and at least one of the inner periphery of the focus ring material, on the side opposite to the side that is joined to the base, are characterized by having a chamfered portion. holding device.

2. A holding device according to claim 1, The porosity of the ceramics forming the insulating portion is greater than the porosity of the ceramics forming the substrate material and the porosity of the ceramics forming the focus ring material. holding device.

3. A holding device according to claim 1 or claim 2, The thermal conductivity of the ceramics forming the insulating portion is smaller than that of the ceramics forming the substrate material for the substrate and the thermal conductivity of the ceramics forming the substrate material for the focus ring. holding device.

4. A holding device according to claim 1 or claim 2, The intermediate portion is characterized in that it is formed so as to move away from the central axis of the holding device from the first joining surface side toward the second joining surface side. holding device.

5. A holding device according to claim 4, In a cross-section including the central axis of the holding device, The length of the aforementioned intermediate portion is characterized by being 1 mm or more. holding device.

6. A holding device according to claim 1 or claim 2, The inner circumference of the base material for the focus ring has a first chamfered portion on the side opposite to the side joined to the base, In a cross-section including the central axis of the holding device, In the stacking direction of the substrate material for the substrate and the substrate material for the focus ring and the base, if the thickness of the substrate material for the focus ring is D and the length of the first chamfered portion is L, then the following formula (1) is satisfied, holding device. 0.2 ≤ L / D ≤ ​​1.4 ... (1)

7. A holding device according to claim 1 or claim 2, The base has a step formed by the intermediate portion between the first joining surface and the second joining surface. The intermediate portion is formed so as to move away from the central axis of the holding device from the first joining surface side toward the second joining surface side, The inner circumference of the base material for the focus ring has a first chamfered portion on the side opposite to the side joined to the base, The outer periphery of the substrate material has a second chamfered portion on the side that is joined to the base, which serves as the chamfered portion. In a cross-section including the central axis of the holding device, The angle between the direction of the normal to the intermediate portion and the direction of the first normal to the first chamfered portion is 90 degrees or less. The angle between the direction of the normal to the intermediate portion and the direction of the second normal to the second chamfered portion is 90 degrees or less. holding device.

8. A holding device for holding a substrate, A substrate base material formed in the shape of a plate from ceramics and having a mounting surface on which the substrate is placed, A focus ring substrate formed in a ring shape from ceramics and positioned on the outer periphery of the substrate material, A base having a first bonding surface to which the substrate material for the substrate is bonded, a second bonding surface to which the focus ring material is bonded, and an intermediate portion located between the first bonding surface and the second bonding surface, It comprises an insulating portion formed of ceramics, which is disposed in the gap formed between the substrate material for the substrate and the substrate material for the focus ring and covers the intermediate portion, The inner circumference of the base material for the focus ring has a first chamfered portion on the side opposite to the side joined to the base, In a cross-section including the central axis of the holding device, In the stacking direction of the substrate material for the substrate and the substrate material for the focus ring and the base, if the thickness of the substrate material for the focus ring is D and the length of the first chamfered portion is L, then the following formula (1) is satisfied, holding device. 0.2 ≤ L / D ≤ ​​1.4 ... (1)

9. A holding device for holding a substrate, A substrate base material formed in the shape of a plate from ceramics and having a mounting surface on which the substrate is placed, A focus ring substrate formed in a ring shape from ceramics and positioned on the outer periphery of the substrate material, A base having a first bonding surface to which the substrate material for the substrate is bonded, a second bonding surface to which the focus ring material is bonded, and an intermediate portion located between the first bonding surface and the second bonding surface, It comprises an insulating portion formed of ceramics, which is disposed in the gap formed between the substrate material for the substrate and the substrate material for the focus ring and covers the intermediate portion, The base has a step formed by the intermediate portion between the first joining surface and the second joining surface. The intermediate portion is formed so as to move away from the central axis of the holding device from the first joining surface side toward the second joining surface side, The inner circumference of the base material for the focus ring has a first chamfered portion on the side opposite to the side joined to the base, The outer periphery of the substrate material has a second chamfered portion on the side that is joined to the base. In a cross-section including the central axis of the holding device, The angle between the direction of the normal to the intermediate portion and the direction of the first normal to the first chamfered portion is 90 degrees or less. The angle between the direction of the normal to the intermediate portion and the direction of the second normal to the second chamfered portion is 90 degrees or less. holding device.

10. A substrate base material formed in the shape of a plate from ceramics and having a mounting surface on which a substrate is placed, A focus ring substrate formed in a ring shape from ceramics and positioned on the outer periphery of the substrate material, A base having a first bonding surface to which the substrate material for the substrate is bonded, a second bonding surface to which the focus ring material is bonded, and an intermediate portion located between the first bonding surface and the second bonding surface, It comprises an insulating portion formed of ceramics, which is disposed in the gap formed between the substrate material for the substrate and the substrate material for the focus ring and covers the intermediate portion, The base has a step formed by the intermediate portion between the first joining surface and the second joining surface. A method for manufacturing a holding device in which at least one of the outer peripheral portion of the substrate material for the substrate that is joined to the base and the inner peripheral portion of the focus ring material opposite to the side that is joined to the base has a chamfered portion, A preparation step of preparing the substrate for the substrate, the substrate for the focus ring, and the base, A bonding step of joining the substrate material for the substrate and the substrate material for the focus ring to the base, The invention is characterized by comprising, after the bonding step, an insulating portion forming step in which the insulating portion is formed in the gap between the outer periphery of the substrate material to be bonded to the base and the inner periphery of the focus ring material material opposite to the side to be bonded to the base, using ceramic thermal spraying. A method for manufacturing a holding device.

11. A method for manufacturing a holding device according to claim 10, In the aforementioned preparation step, A focus ring substrate having a first chamfered portion on its inner circumference, wherein in a cross-section including the central axis of the focus ring substrate, the relationship between its own thickness D and the length L of the first chamfered portion is 0.2 ≤ L / D ≤ ​​1.4, The substrate material having a second chamfered portion on its outer periphery, A base is prepared having a step formed by the intermediate portion between the first joining surface and the second joining surface, the intermediate portion being formed so as to move away from the central axis of the base from the first joining surface side to the second joining surface side, and the length of the intermediate portion being 1 mm or more in a cross-section including the central axis of the base. In the aforementioned joining process, The focus ring substrate is positioned relative to the base such that the first chamfered portion is located on the side opposite to the side joined to the base, and in a cross-section including the central axis of the base, the angle between the direction of the normal to the intermediate portion and the direction of the first normal to the first chamfered portion is 90 degrees or less. The substrate material is positioned relative to the base such that the second chamfered portion is located on the side to be joined to the base, and in a cross-section including the central axis of the base, the angle between the direction of the normal to the intermediate portion and the direction of the second normal to the second chamfered portion is 90 degrees or less. The substrate material for the substrate and the substrate material for the focus ring are joined to the base, A method for manufacturing a holding device.

12. A substrate material formed in the shape of a plate from ceramics and having a mounting surface on which a substrate is placed, A focus ring substrate formed in a ring shape from ceramics and positioned on the outer periphery of the substrate material, A base having a first bonding surface to which the substrate material for the substrate is bonded, a second bonding surface to which the focus ring material is bonded, and an intermediate portion located between the first bonding surface and the second bonding surface, A method for manufacturing a holding device comprising an insulating portion formed of ceramics, which is disposed in the gap formed between the substrate material for the substrate and the substrate material for the focus ring and covers the intermediate portion, A preparation step of preparing the substrate for the substrate, the substrate for the focus ring, and the base, A bonding step of joining the substrate material for the substrate and the substrate material for the focus ring to the base, The process includes, after the bonding step, an insulating portion forming step in which the insulating portion is formed in the gap between the substrate material for the substrate and the substrate material for the focus ring using ceramic thermal spraying, In the aforementioned preparation step, A focus ring substrate having a first chamfered portion on its inner circumference, wherein in a cross-section including the central axis of the focus ring substrate, the relationship between its own thickness D and the length L of the first chamfered portion is 0.2 ≤ L / D ≤ ​​1.4, The substrate material having a second chamfered portion on its outer periphery, A base is prepared having a step formed by the intermediate portion between the first joining surface and the second joining surface, the intermediate portion being formed so as to move away from the central axis of the base from the first joining surface side to the second joining surface side, and the length of the intermediate portion being 1 mm or more in a cross-section including the central axis of the base. In the aforementioned joining process, The focus ring substrate is positioned relative to the base such that the first chamfered portion is located on the side opposite to the side joined to the base, and in a cross-section including the central axis of the base, the angle between the direction of the normal to the intermediate portion and the direction of the first normal to the first chamfered portion is 90 degrees or less. The substrate material is positioned relative to the base such that the second chamfered portion is located on the side to be joined to the base, and in a cross-section including the central axis of the base, the angle between the direction of the normal to the intermediate portion and the direction of the second normal to the second chamfered portion is 90 degrees or less. The substrate material for the substrate and the substrate material for the focus ring are joined to the base, A method for manufacturing a holding device.

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