Holding device, and method for manufacturing a holding device

Abstract

This technology provides an improved degree of design freedom for holding devices. [Solution] A holding device comprising: a base having a fluid channel through which fluid flows and which includes a bent portion; a plate-shaped substrate for a substrate placed on the base, having a mounting surface on which a substrate is placed, an opening formed in the mounting surface, and a through hole connecting the fluid channel of the base to the opening; and a ceramic sintered body placed inside the through hole, having a porous portion and a cylindrical dense portion placed outside the porous portion, wherein the end of the ceramic sintered body reaches inside the fluid channel.

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 for improving the design freedom in the 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 improving the design freedom 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 base having a fluid channel through which fluid flows and which includes a bent portion; a plate-shaped substrate material disposed on the base, having a mounting surface on which the substrate is placed, an opening formed in the mounting surface, and a through hole connecting the fluid channel of the base to the opening; and a ceramic sintered body disposed inside the through hole, having a porous portion and a cylindrical dense portion disposed outside the porous portion, wherein the end of the ceramic sintered body reaches inside the fluid channel.

[0008] In this configuration, the ceramic sintered body, which has a porous portion and a cylindrical dense portion located outside the porous portion, has its ends extending into the flow channel inside the base. This prevents, for example, the fluid flowing through the flow channel from leaking and coming into contact with the conductive film when a conductive film is placed between the base and the substrate, thereby suppressing abnormal discharge due to ionization of the leaked fluid. Furthermore, the ceramic sintered body is positioned inside the through-hole through an opening formed in the mounting surface of the substrate. This allows the ceramic sintered body to be attached to the substrate regardless of the shape of the flow channel in the base. Therefore, the design flexibility of a holding device equipped with a ceramic sintered body that suppresses abnormal discharge can be improved.

[0009] (2) In the above-described holding device, the substrate material and the ceramic sintered body do not need to be joined by a bonding material. With this configuration, the ceramic sintered body is joined to the substrate material without the use of a bonding material. This makes it possible to suppress the generation of foreign matter and contamination originating from the bonding material in the environment in which the holding device is used.

[0010] (3) In the above-described holding device, the ceramic sintered body is positioned on the base side of the mounting surface described above, and in a cross-section including the central axis of the holding device, the length of the ceramic sintered body in the stacking direction between the base and the substrate material may be 1.5 times or more the thickness of the substrate material in the stacking direction. With this configuration, for example, when a conductive film is placed between the base and the substrate material, the end face of the ceramic sintered body on the base side is located relatively far from the conductive film. As a result, the fluid in the flow path, which tends to be relatively high pressure, has difficulty passing between the base and the ceramic sintered body, thus suppressing contact between the fluid and the conductive film. Therefore, the occurrence of abnormal discharge can be further suppressed.

[0011] (4) In the above-described holding device, the substrate material for the substrate has a reference surface and a plurality of protrusions erected on the reference surface, the mounting surface is formed by the tip surfaces of each of the plurality of protrusions, and the ceramic sintered body may be positioned on the base side of the reference surface. With this configuration, the ceramic sintered body is positioned on the base side of the reference surface. Since the mounting surface on which the substrate is placed is formed by the tip surfaces of the plurality of protrusions erected on the reference surface, the ceramic sintered body and the substrate are unlikely to come into contact. Therefore, the design tolerance of the holding device can be made relatively large, and the degree of freedom in designing the holding device can be improved.

[0012] (5) In the holding device of the above form, the opening has a recessed shape with respect to the mounting surface described above, and an opening surface is formed that is located on the base side of the mounting surface described above, and the end of the ceramic sintered body opposite to the base may be located on the mounting surface side of the opening surface. With this configuration, a groove is formed inside the opening around the end of the ceramic sintered body opposite to the base, through which airflow flows via the porous portion. As a result, for example, etching residue generated from the substrate in an etching process using plasma can be collected in the groove by airflow via the porous portion. In addition, since the distance between the substrate placed on the mounting surface and the ceramic sintered body is relatively small, the occurrence of abnormal discharge in an etching process using plasma can be suppressed.

[0013] (6) In the above-described holding device, the end face of the end of the ceramic sintered body opposite to the base may have a V-shaped curved surface. With this configuration, the distance between the substrate placed on the mounting surface and the end of the ceramic sintered body opposite to the base becomes relatively small, which can suppress the occurrence of abnormal discharge in the etching process using plasma.

[0014] (7) In the above-described holding device, the end of the porous portion opposite to the base may have a valley-shaped curved surface. With this configuration, for example, when sandblasting is used to form multiple protrusions on the reference surface of a substrate material, the end of the porous portion opposite to the base is processed to have a valley-shaped curved surface. That is, in the process of processing multiple protrusions, the end of the porous portion opposite to the base can be processed. Therefore, some of the steps included in the manufacturing method of the holding device can be simplified.

[0015] (8) In the above-described form of the holding device, the substrate material and the ceramic sintered body are joined by a bonding material, and in a cross-section including the central axis of the holding device, the ceramic sintered body may be formed such that its width decreases from the mounting surface side toward the base side. With this configuration, when the substrate material and the ceramic sintered body are joined by the bonding material, the adhesion between the inside of the through hole and the outside of the ceramic sintered body can be improved. This makes it possible to suppress fluid leakage in the bonding material.

[0016] (9) In the above-described form of the holding device, the porous portion has a communication hole that connects the inside of the flow path to the outside of the holding device, and the inner diameter of the communication hole may be 0.1 mm or less. With this configuration, fluid can easily move between the inside of the flow path and the outside of the holding device by passing through the communication hole. In addition, since the inner diameter of the communication hole is 0.1 mm or less, the occurrence of abnormal discharge via the fluid passing through the communication hole can be suppressed.

[0017] (10) In the above-described form of the holding device, the porous portion may have a recess at at least one of the end on the base side and the end on the opposite side of the base. With this configuration, the pressure loss of the fluid passing through the porous portion can be reduced to some extent, making it easier for the fluid to move between the inside of the flow path and the outside of the holding device.

[0018] (11) In the above-described holding device, the substrate material for the substrate is formed from a material mainly composed of aluminum nitride or alumina, and the base may be a sintered body formed from a material mainly composed of silicon carbide, or a sintered body formed from a material containing silicon carbide and having a thermal conductivity of 70 W / mK or more. With this configuration, the aluminum nitride, which is the main component forming the substrate material for the substrate, and the silicon carbide forming the base each have relatively high thermal conductivity. As a result, heat can be transferred from the mounting surface relatively quickly, and the occurrence of thermal problems can be suppressed even in processes that use relatively high-density energy.

[0019] (12) In the above-described holding device, the average linear thermal expansion coefficient of the material forming the ceramic sintered body may be greater than the average linear thermal expansion coefficient of the material forming the substrate for the substrate and the average linear thermal expansion coefficient of the material forming the base. With this configuration, when the temperature of the holding device rises, the ceramic sintered body expands to be larger than the size of the through-holes and flow channels. As a result, the ceramic sintered body receives compressive stress from the inner walls of the through-holes and flow channels, which improves the adhesion between the ceramic sintered body and the inner walls of the through-holes and flow channels. Therefore, the fluid flowing through the flow channels has difficulty passing between the base and the ceramic sintered body, which further suppresses the occurrence of abnormal discharges.

[0020] (13) In the above-described form of the holding device, the ceramic sintered body may be formed from a material mainly composed of alumina. With this configuration, the ceramic sintered body is formed from a material mainly composed of alumina of relatively high purity. This makes it possible to suppress the generation of foreign matter and contamination originating from the ceramic sintered body in the environment in which the holding device is used.

[0021] (14) According to another embodiment of the present invention, a method for manufacturing a holding device is provided. This method for manufacturing a holding device comprises a preparation step of preparing the base, the substrate material, and the ceramic sintered body; a joining step of joining the base and the substrate material; and a fixing step, after the joining step, of inserting the ceramic sintered body into the through-hole through the opening in the substrate material and fixing the ceramic sintered body to the substrate material. With this configuration, after the joining step of joining the base and the substrate material, the ceramic sintered body is inserted into the through-hole through the opening in the substrate material and fixed to the substrate material. This improves the degree of freedom of the shape of the flow path in the base having a flow path including a bent portion. Therefore, it is possible to improve the degree of freedom in designing a holding device equipped with a ceramic sintered body that suppresses abnormal discharge.

[0022] (15) In the method for manufacturing the holding device of the above-described embodiment, in the preparation step, a conductive film may be prepared, and in the bonding step, the substrate base material and the base may be bonded so that the conductive film is positioned between the substrate base material and the base. According to this configuration, the conductive film is positioned between the substrate base material and the base, and the end of the ceramic sintered body reaches the inside of the flow path inside the base. Thereby, contact between the fluid flowing through the flow path and the conductive film can be suppressed. Therefore, a holding device that can further suppress the occurrence of abnormal discharge can be manufactured.

[0023] Note that the present invention can be realized in various modes. For example, a method for repairing a holding device, a system including a holding device, a control method for a holding device and a system including the holding device, a computer program for causing a substrate to be held in a holding device and a system including the holding device, a server device for distributing the computer program, and a non-temporary storage medium storing the computer program.

Brief Description of Drawings

[0024] [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 a first diagram for explaining a method for manufacturing a ceramic sintered body. [[ID=)22]] [Figure 5] It is a second diagram for explaining a method for manufacturing a ceramic sintered body. [Figure 6] It is a first diagram for explaining a method for manufacturing the holding device of the first embodiment. [Figure 7] It is a second diagram for explaining a method for manufacturing the holding device of the first embodiment. [Figure 8] It is a third diagram for explaining a method for manufacturing the holding device of the first embodiment. [Figure 9] It is a fourth diagram for explaining a method for manufacturing the holding device of the first embodiment. [Figure 10] This is an enlarged cross-sectional view of the holding device of the second embodiment. [Figure 11] This is an enlarged cross-sectional view of the holding device of the third embodiment. [Figure 12] This is an enlarged cross-sectional view of the holding device according to the fourth embodiment. [Figure 13] This is an enlarged cross-sectional view of the holding device according to the fifth embodiment. [Figure 14] This is an enlarged cross-sectional view of the holding device according to the sixth embodiment. [Figure 15] This is an enlarged cross-sectional view of the holding device according to the seventh embodiment. [Figure 16] This is an enlarged cross-sectional view of the holding device according to the eighth embodiment. [Figure 17] This is an enlarged cross-sectional view of the holding device according to the ninth embodiment. [Figure 18] This is an enlarged cross-sectional view of the holding device according to the tenth embodiment. [Figure 19] This is an enlarged cross-sectional view of a modified example of the holding device of the first embodiment. [Modes for carrying out the invention]

[0025] <First Embodiment> Figure 1 is a perspective view of the holding device 1A of the first embodiment. Figure 2 is a cross-sectional view of the holding device 1A of the first embodiment. Figure 3 is an enlarged view of part A in Figure 2. The holding device 1A 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 1A of this embodiment comprises a base 10, a substrate material 20, a ceramic sintered body 30A, a joint 41, and a conductive film 42. In the holding device 1A, as shown in Figure 1, the base 10, conductive film 42, joint 41, and substrate material 20 are stacked in that order. In Figures 1 and 2, for convenience, the stacking direction of the base 10 and the substrate material 20 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 clarity, the size relationships of the base 10, substrate material 20, ceramic sintered body 30A, joint 41, and conductive film 42 in Figures 1, 2, and 3 differ from the actual relationships.

[0026] The base 10 is a roughly cylindrical member that forms the base of the holding device 1A. The base 10 is a sintered body mainly composed of silicon carbide (SiC). Here, "main component" means the component with the highest proportion. From the viewpoint of cooling function, the thermal conductivity of the material forming the base 10 is preferably 70 W / mK or higher. However, the material forming the base 10 is not limited to a material mainly composed of silicon carbide. The base 10 may be formed from a material to which at least one of metal carbides, metal nitrides, and metal silicides is added to silicon carbide, aluminum (Al), titanium (Ti), molybdenum (Mo), tungsten (W), alloys thereof, SUS, a composite of metal and ceramics such as Al-SiC, or a material mainly composed of ceramics such as aluminum nitride (AlN) or alumina (Al2O3).

[0027] As shown in Figures 2 and 3, which are cross-sections including the central axis C1 of the holding device 1A, the base 10 has a fluid passage 11 inside, which includes a bent portion 11a. The passage 11 has a first passage 11b that extends horizontally, including the x-axis and y-axis directions, and a plurality of second passages 11c, 11d that extend in the z-axis direction. The bent portion 11a connects the first passage 11b and the second passages 11c, 11d. As shown in Figure 2, the second passages 11c and 11d are formed so that their positions are offset in the z-axis direction. In other words, the passage 11 is not formed in a straight line on the base 10.

[0028] In this embodiment, the second channel 11c, which connects to the positive side in the z-axis direction of the first channel 11b, is formed such that the size of the positive side in the z-axis direction is larger. As a result, a stepped surface 10a is formed on the inner wall of the second channel 11c (see Figure 3). An inert gas such as helium gas flows through the channel 11. The base 10 of this embodiment has a refrigerant channel (not shown) through which a refrigerant such as a fluorine-based inert liquid or water flows. As shown in Figure 2, the base 10 is larger than the substrate material 20, which will be described later. However, the size relationship between the base 10 and the substrate material 20 is not limited to this. They may be the same size.

[0029] The substrate material 20 is a plate-shaped member placed on the base 10. In this embodiment, the substrate material 20 has a reference surface 20c, a plurality of protrusions 20d erected on the reference surface 20c, and an opening surface 20e on one of the pair of main surfaces 20a and 20b of the substrate material 20 that is opposite to the base 10. The reference surface 20c is located closer to the base 10 than one of the main surfaces 20a of the substrate material 20. The opening surface 20e is located closer to the base 10 than the reference surface 20c. The substrate material 20 is mainly composed of ceramics. In this embodiment, the substrate material 20 is formed from a material mainly composed of aluminum nitride. The substrate material 20 may also be formed from other ceramics such as alumina.

[0030] The substrate material 20 for the substrate has a mounting surface 21 on which the substrate W is placed, an opening 22 formed in the mounting surface 21, a through hole 23 that connects the flow path 11 of the base 10 to the opening 22, and a chuck electrode 24. In the substrate material 20 for the substrate of this embodiment, the mounting surface 21 is formed by the tip surfaces 20f of each of the multiple protrusions 20d, as shown in Figure 3. Specifically, when the holding device 1A holds the substrate W, as shown in Figure 2, the substrate W is in contact with the tip surfaces 20f of each of the multiple protrusions 20d and the outer peripheral surface 20g of one of the main surfaces 20a of the substrate material 20.

[0031] The opening 22 is an open portion in the opening surface 20e formed on one of the main surfaces 20a of the substrate material 20. The opening 22 has a recessed shape with respect to the reference surface 20c. The depth of the opening 22 in the stacking direction (z-axis direction) is, for example, 15 μm.

[0032] The through-hole 23 is located on the negative side in the z-axis direction relative to the opening 22 in the substrate material 20. The inner size of the through-hole 23 is the same as the inner size of the positive side in the z-axis direction of the second channel 11c of the channel 11 that the base 10 has.

[0033] The chuck electrode 24 is located inside the substrate material 20. The chuck electrode 24 is made of a conductive material such as tungsten or molybdenum. The chuck electrode 24 is connected to an external power source via electrode terminals (not shown). When power is supplied from the external power source, the chuck electrode 24 generates an electrostatic attraction force that allows the substrate W to be attracted and held to the mounting surface 21 of the substrate material 20. In addition to the chuck electrode 24, or in place of the chuck electrode 24, high-frequency electrodes or heater electrodes may be placed on the substrate material 20.

[0034] The ceramic sintered body 30A is a ceramic sintered body placed inside the through-hole 23 of the substrate material 20. In this embodiment, the ceramic sintered body 30A is formed from a material mainly composed of alumina and has a substantially cylindrical shape. The ceramic sintered body 30A has insulating properties and is provided to suppress discharge using the through-hole 23 and the flow path 11 as discharge paths in a plasma etching process. In this embodiment, the average linear thermal expansion coefficient of the material forming the ceramic sintered body 30A is greater than the average linear thermal expansion coefficient of the material forming the substrate material 20 and the average linear thermal expansion coefficient of the material forming the base 10.

[0035] The ceramic sintered body 30A has a porous portion 31 and a cylindrical dense portion 32 located outside the porous portion 31. The porous portion 31 is a substantially cylindrical portion having a relatively large number of pores. Some of the multiple pores formed in the porous portion 31 are in communication with each other, forming a channel through which the inert gas flowing through the channel 11 can pass. In other words, the porous portion 31 is gas permeable. The porosity of the porous portion 31 is preferably 50% or more, and more preferably 60% or more. The dense portion 32 is a portion of the ceramic sintered body 30A that is formed more densely than the porous portion 31 and has a substantially cylindrical shape. The ceramic sintered body 30A has a substantially cylindrical shape, and the porous portion 31 and the dense portion 32 are formed integrally. In this embodiment, the difference between the outer diameter of the ceramic sintered body 30A and the inner size of the through hole 23 in the substrate material 20 is 0.05 mm to 0.5 mm, and the outer diameter of the ceramic sintered body 30A is smaller than the inner diameter of the through hole 23 in the substrate material 20.

[0036] In this embodiment, the ceramic sintered body 30A and the substrate material 20 are joined by an adhesive layer 33. The adhesive layer 33 is formed from a heat-resistant material such as a silicone resin, and a filler such as alumina is added. This increases the glass phase transition temperature of the adhesive layer 33, thereby improving the heat resistance of the adhesive layer 33.

[0037] As shown in Figure 3, the ceramic sintered body 30A is positioned on the base 10 side of the reference surface 20c. Specifically, the ceramic sintered body 30A is positioned such that the end face of the positive z-axis end 301 is located in the negative z-axis direction relative to the reference surface 20c. That is, the ceramic sintered body 30A is positioned on the base 10 side of the mounting surface 21. In this embodiment, as shown in Figure 3, the end face of the end 301 of the ceramic sintered body 30A is located on substantially the same plane as the opening surface 20e.

[0038] As shown in Figure 3, in a cross-section including the central axis C1 of the holding device 1A, the length L of the ceramic sintered body 30A in the stacking direction between the base 10 and the substrate material 20 is 1.5 times or more the thickness D of the substrate material 20 in the stacking direction. For example, if the thickness D of the substrate material 20 in the stacking direction is 1.3 mm, the length L of the ceramic sintered body 30A will be about 3 mm, and the ratio of the length L of the ceramic sintered body 30A to the thickness D of the substrate material 20 in the stacking direction will be approximately 2.3. The negative end 302 in the z-axis direction of the ceramic sintered body 30A reaches the inside of the flow channel 11. Specifically, as shown in Figure 2, the ceramic sintered body 30A is positioned such that the end face of the negative end 302 in the z-axis direction of the ceramic sintered body 30A is in contact with the stepped surface 10a formed on the inner wall of the flow channel 11 of the base 10. Note that, for the sake of explanation, the relationship between the thickness D of the substrate material 20 and the length L of the ceramic sintered body 30A in Figure 3 differs from the actual relationship.

[0039] The joint portion 41 is positioned between the base 10 and the substrate material 20. The joint portion 41 is a metal bonding material mainly composed of indium (In), and it bonds the base 10 and the substrate material 20 via a conductive film 42, which will be described later. The joint portion 41 is not limited to a metal bonding material mainly composed of indium, but may also be a silicone-based organic bonding material, a soldering material containing hard solder or soft solder, an inorganic bonding material, or a metal bonding material containing metals other than indium, such as gold (Au) or aluminum.

[0040] The conductive film 42 is positioned between the joint 41 and the base 10. The conductive film 42 is made of aluminum. When the holding device 1A is used in a process involving plasma, the conductive film 42 can apply high-frequency power to the holding device 1A.

[0041] Next, the manufacturing method of the holding device 1A of this embodiment will be described. The holding device 1A is manufactured by separately manufacturing the base 10, the substrate material 20, and the ceramic sintered body 30A, joining the base 10 and the substrate material 20 by the joint 41, and then attaching the ceramic sintered body 30A to the substrate material 20.

[0042] In the manufacturing method of the holding device 1A, first, the base 10, the substrate 20 for the substrate, and the ceramic sintered body 30A are prepared (preparation step). In the production of the base 10, a binder is added to a raw material powder containing silicon carbide and an additive 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 10 are produced from the ingot of the molded body. Each of the multiple molded bodies becomes a sintered body by firing. A groove to form a flow channel 11 is machined into a specific sintered body among the multiple sintered bodies, and the base 10 having a flow channel 11 is produced by joining it with another sintered body. After joining the multiple sintered bodies, the final shape may be processed. Note that the manufacturing method of the base 10 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, holes or grooves corresponding to the flow path 11 are machined into a specific green sheet among the multiple green sheets. Then, the base 10 may be manufactured by firing a laminate of green sheets, which includes the specific green sheet with holes or grooves machined into it.

[0043] In the preparation of the substrate material 20, 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, using a metallizing paste, the portion that will become the chuck electrode 24 is printed onto a specific green sheet from among the multiple green sheets, for example, using a screen printing device. Next, the aluminum nitride plate, which will become the substrate material 20, is produced by firing a laminate of green sheets, which is made by stacking multiple green sheets, including the specific green sheet on which the metallizing paste has been printed. Note that the manufacturing method of the substrate material 20 is not limited to this. For example, a binder may be added to a raw material powder containing additives such as yttrium oxide to aluminum nitride powder to granulate powder, and the granulated powder may be 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 granulated powder is further filled onto the placed planar electrode, and then fired while applying pressure in a uniaxial direction with a carbon punch (powder hot press method). The substrate material 20 for the circuit board can also be manufactured by this powder hot pressing method.

[0044] Figure 4 is the first diagram illustrating the manufacturing method of the ceramic sintered body 30A. Figure 5 is the second diagram illustrating the manufacturing method of the ceramic sintered body 30A. In the production of the ceramic sintered body 30A, first, a plate-shaped molded body C30 mainly composed of alumina is prepared. The molded body C30 may be either a degreased body or a calcined body. Next, multiple through holes H31 are processed into the molded body C30, and each of the through holes H31 is filled with a porous body paste P31 (see the white arrow F1 in Figure 4). The porous body paste P31 is made by kneading a mixture containing, for example, alumina powder, a pore-forming material that disappears during firing such as resin beads, a binder, and an organic solvent. Methods for filling the through holes H31 with the porous body paste P31 include, for example, using an injection molding apparatus or a screen printing apparatus. Next, the molded body C30 with the porous body paste P31 filled into the through holes H31 is fired at atmospheric pressure. As a result, the molded body C30 and the alumina contained in the porous paste P31 are sintered, forming a sintered body S30 in which the porous portion 31, which is based on the porous paste P31, and the fired molded body C30 are integrated (see Figure 5). Next, the porous portion 31 is cut out from the sintered body S30 so as to include the portion in contact with the porous portion 31 (see the white arrow F2 in Figure 5). This produces a ceramic sintered body 30A in which the portion in contact with the porous portion 31 is a dense portion 32. In Figures 4 and 5, multiple through holes H31 are processed in the plate-shaped molded body C30, which is mainly composed of alumina, so that multiple ceramic sintered bodies 30A can be produced at once, but the number of ceramic sintered bodies 30A produced at once is not limited to this. Furthermore, the method for manufacturing the ceramic sintered body 30A is not limited to this.

[0045] Figure 6 is the first diagram illustrating the manufacturing method of the holding device of this embodiment. In the manufacturing method of the holding device 1A, after the preparation step, the base 10 and the aluminum nitride plate P20 which will become the substrate material 20 are joined (joining step). Specifically, as shown in Figure 6, a conductive sheet S42 which will become the conductive film 42 and a bonding sheet S41 which will become the joining portion 41 are placed on the surface of the base 10 in which the flow channel 11 is formed, and the aluminum nitride plate P20 is joined to the base 10 via the bonding sheet S41 (white arrow F3 in Figure 6).

[0046] Figure 7 is a second diagram illustrating the manufacturing method of the holding device of this embodiment. In the manufacturing method of the holding device 1A, after the joining process, the aluminum nitride plate P20 is processed to create openings 22 and the like (processing process). Specifically, the surface P20a of the aluminum nitride plate P20 is processed to form openings 22 and through holes 23. When processing the through holes 23, the joining portion 41 and the conductive film 42 are also processed simultaneously from the aluminum nitride plate P20 side to form a stepped surface 10a on the inner wall of the flow path 11 of the base 10. Alternatively, after the preparation process, the aluminum nitride plate P20 may be processed to form openings 22 and part of the through holes 23 (processing process), and then in the joining process, the base 10 and the aluminum nitride plate P20 which will become the substrate material 20 may be joined.

[0047] Figure 8 is a third diagram illustrating the manufacturing method of the holding device of this embodiment. In the manufacturing method of the holding device 1A, following the processing step, a plurality of protrusions 20d are formed on the aluminum nitride plate P20 (protrusion formation step). Specifically, the surface P20a of the aluminum nitride plate P20 is processed to form a plurality of protrusions 20d. As a result, a reference surface 20c is formed between the plurality of protrusions 20d.

[0048] Figure 9 is a fourth diagram illustrating the manufacturing method of the holding device of this embodiment. In the manufacturing method of the holding device 1A, following the projection formation step, the ceramic sintered body 30A is fixed to the aluminum nitride plate P20 (fixing step). Specifically, as shown in Figure 9, the ceramic sintered body 30A is inserted into the through hole 23 through the opening 22 of the aluminum nitride plate P20, thereby fixing the ceramic sintered body 30A to the aluminum nitride plate P20. More specifically, a bonding material containing a silicone resin and a filler formed from alumina is poured into the space Sp between the ceramic sintered body 30A and the aluminum nitride plate P20 (white arrow F4 in Figure 9) to bond the ceramic sintered body 30A and the aluminum nitride plate P20. This completes the manufacturing of the holding device 1A. Note that the manufacturing method of the holding device 1A is not limited to this.

[0049] As described above, in the holding device 1A of this embodiment, the ceramic sintered body 30A, which has a porous portion 31 and a cylindrical dense portion 32 located outside the porous portion 31, has its end portion 302 extending to the inside of the flow path 11 inside the base 10. This prevents the inert gas flowing through the flow path 11 from coming into contact with the conductive film 42, thereby suppressing abnormal discharge. Furthermore, the ceramic sintered body 30A is positioned inside the through hole 23 through an opening 22 formed in the mounting surface 21 of the substrate material 20. This allows the ceramic sintered body 30A to be attached to the substrate material 20 regardless of the shape of the flow path 11 of the base 10. Therefore, the design freedom of the holding device 1A equipped with the ceramic sintered body 30A that suppresses abnormal discharge can be improved.

[0050] Furthermore, according to the holding device 1A of this embodiment, the ceramic sintered body 30A is an insulating ceramic sintered body in which a porous portion 31 with a relatively high porosity and a dense portion 32 formed to cover the outer periphery of the porous portion 31 are integrally formed. As a result, as explained with reference to Figures 4 and 5, it is not necessary to separately create and combine the porous portion 31 and the dense portion 32, making it relatively easy to manufacture. In addition, since the porous portion 31 and the dense portion 32 are less likely to separate when the holding device 1A is in use, abnormal discharge due to leakage of inert gas between the porous portion 31 and the dense portion 32 can be suppressed.

[0051] Furthermore, according to the holding device 1A of this embodiment, the end face 302 of the end portion 302 of the ceramic sintered body 30A on the base 10 side is located relatively far from the conductive film 42 which is placed between the base 10 and the substrate material 20. As a result, the inert gas in the flow path 11, which tends to become high pressure, passes between the base 10 and the ceramic sintered body 30A and is less likely to come into contact with the conductive film 42. Therefore, the occurrence of abnormal discharge can be further suppressed.

[0052] Furthermore, according to the holding device 1A of this embodiment, the length L of the ceramic sintered body 30A is 1.5 times or more the thickness D of the substrate material 20, and the length L of the ceramic sintered body 30A is a certain length longer than the thickness D of the substrate material 20. As a result, even if the substrate material 20 is thin because the holding device 1A is used in a process that uses relatively high-density energy, the length of the ceramic sintered body 30A can be sufficiently secured, thereby suppressing abnormal discharge.

[0053] Furthermore, according to the holding device 1A of this embodiment, the ceramic sintered body 30A is positioned on the base 10 side of the reference surface 20c. Since the mounting surface 21 on which the substrate W is placed is formed by the tip surfaces 20f of a plurality of protrusions 20d erected on the reference surface 20c, the ceramic sintered body 30A and the substrate W are unlikely to come into contact. Therefore, the design tolerance of the holding device 1A can be made relatively large, thereby improving the design freedom of the holding device 1A.

[0054] Furthermore, in the holding device 1A of this embodiment, both aluminum nitride, which is the main component forming the substrate material 20, and silicon carbide, which is the main component forming the base 10, have relatively high thermal conductivity. As a result, heat on the mounting surface 21 can be transferred relatively quickly, and thus the occurrence of thermal problems can be suppressed even in processes that use relatively high-density energy.

[0055] Furthermore, according to the holding device 1A of this embodiment, the average linear thermal expansion coefficient of the material forming the ceramic sintered body 30A is greater than the average linear thermal expansion coefficient of the material forming the substrate material 20 and the average linear thermal expansion coefficient of the material forming the base 10. As a result, when the temperature of the holding device 1A rises during use, the ceramic sintered body 30A receives compressive stress from the through holes 23 and the inner walls of the flow channels 11, thereby improving the adhesion between the ceramic sintered body 30A and the through holes 23 and the inner walls of the flow channels 11. Consequently, the inert gas flowing through the flow channels 11 has difficulty passing between the base 10 and the ceramic sintered body 30A, further suppressing the occurrence of abnormal discharges.

[0056] Furthermore, according to the holding device 1A of this embodiment, the ceramic sintered body 30A is formed from a material mainly composed of relatively high-purity alumina. As a result, in the environment in which the holding device 1A is used, the generation of foreign matter from the ceramic sintered body 30A and contamination of the substrate W by trace components contained in the ceramic sintered body 30A can be suppressed.

[0057] Furthermore, according to the manufacturing method of the holding device 1A of this embodiment, after the joining process of joining the base 10 and the substrate material 20, the ceramic sintered body 30A is inserted into the through hole 23 through the opening 22 of the substrate material 20, thereby fixing the ceramic sintered body 30A to the substrate material 20. As a result, the ceramic sintered body 30A can be fixed to the substrate material 20 regardless of the shape of the flow path 11, thereby improving the degree of freedom in the shape of the flow path 11 in the base 10. Therefore, the degree of freedom in designing the holding device 1A equipped with the ceramic sintered body 30A that suppresses abnormal discharge can be improved.

[0058] Furthermore, according to the manufacturing method of the holding device 1A of this embodiment, the conductive film 42 is located between the substrate material 20 and the base 10, and the ceramic sintered body 30A has its end extending to the inside of the flow path within the base 10. This makes it possible to suppress contact between the inert gas flowing through the flow path 11 and the conductive film 42, thereby further suppressing the occurrence of abnormal discharge.

[0059] <Second Embodiment> Figure 10 is an enlarged cross-sectional view of the holding device 2 of the second embodiment. The holding device 2 of the second embodiment differs from the holding device 1A of the first embodiment (Figure 3) in its method of fixing the ceramic sintered body.

[0060] The holding device 2 of the second embodiment comprises a base 10, a substrate material 20 for the substrate, a ceramic sintered body 50, a joint 41, and a conductive film 42. The holding device 2 is an electrostatic chuck that attracts and holds the substrate W by electrostatic attraction.

[0061] The ceramic sintered body 50 is a ceramic sintered body that is placed inside the through hole 23 of the substrate material 20. The ceramic sintered body 50 has a porous portion 31 and a cylindrical dense portion 32 located outside the porous portion 31. Compared to the ceramic sintered body 30A of the first embodiment, the ceramic sintered body 50 is larger in size relative to the through hole 23. Specifically, the difference between the outer diameter of the ceramic sintered body 50 and the inner size of the through hole 23 of the substrate material 20 is 0.005 mm to 0.1 mm, and a portion of the outer diameter of the ceramic sintered body 50 is larger than the inner diameter of the through hole 23 of the substrate material 20. In the holding device 2, the ceramic sintered body 50 is not fixed to the substrate material 20 by a bonding material. That is, the holding device 2 does not have the adhesive layer 33 of the holding device 1A of the first embodiment between the substrate material 20 and the ceramic sintered body 50. In this embodiment, the average linear thermal expansion coefficient of the material forming the ceramic sintered body 50 is greater than the average linear thermal expansion coefficient of the material forming the substrate 20 and the average linear thermal expansion coefficient of the material forming the base 10.

[0062] In the manufacturing method of the holding device 2 of this embodiment, in the fixing step following the projection formation step, the ceramic sintered body 50 is fixed to the aluminum nitride plate P20 by press-fitting. Specifically, for example, a press machine is used to push the ceramic sintered body 50 into the through hole 23 through the opening 22, thereby press-fitting it. This fixes the ceramic sintered body 50 to the substrate material 20.

[0063] As described above, according to the holding device 2 of this embodiment, the ceramic sintered body 50, which has a porous portion 31 and a cylindrical dense portion 32 located outside the porous portion 31, has its end portion 302 extending to the inside of the flow path 11 inside the base 10. This prevents the inert gas flowing through the flow path 11 from coming into contact with the conductive film 42, thereby suppressing abnormal discharge. Furthermore, the ceramic sintered body 50 is positioned inside the through hole 23 via the opening 22. This allows the ceramic sintered body 50 to be attached to the substrate material 20 regardless of the shape of the flow path 11 in the base 10. Therefore, the design freedom of the holding device 2 equipped with a ceramic sintered body 50 that suppresses abnormal discharge can be improved.

[0064] Furthermore, according to the holding device 2 of this embodiment, the ceramic sintered body 50 has a dense portion 32 that is formed to cover the outer periphery of the porous portion 31, which has a relatively large porosity. As a result, the size of the ceramic sintered body 50 can be precisely matched to the size of the inside of the through hole 23, and thus the strength can be set to a certain level or higher when fixing it to the substrate material 20 by press-fitting.

[0065] Furthermore, according to the holding device 2 of this embodiment, the ceramic sintered body 50 is joined to the substrate material 20 for the substrate by press-fitting into the through hole 23 without using a bonding material. As a result, in the environment in which the holding device 2 is used, the generation of foreign matter originating from the bonding material and contamination of the substrate W by trace components contained in the bonding material can be suppressed.

[0066] Furthermore, according to the holding device 2 of this embodiment, the average linear thermal expansion coefficient of the material forming the ceramic sintered body 50 is greater than that of the material forming the substrate material 20 and the material forming the base 10. As a result, when the temperature of the holding device 2 rises during use, the ceramic sintered body 50 receives compressive stress from the through holes 23 and the inner walls of the flow channels 11, thereby improving the adhesion between the ceramic sintered body 50 and the through holes 23 and the inner walls of the flow channels 11. Consequently, the inert gas flowing through the flow channels 11 has difficulty passing between the base 10 and the ceramic sintered body 50, further suppressing the occurrence of abnormal discharges.

[0067] <Third Embodiment> Figure 11 is an enlarged cross-sectional view of the holding device 3 of the third embodiment. Compared to the holding device 1A of the first embodiment (Figure 3), the holding device 3 of the third embodiment differs in the method of fixing the ceramic sintered body.

[0068] The holding device 3 of the third embodiment comprises a base 10, a substrate material 20 for the substrate, a ceramic sintered body 60, a joint 41, and a conductive film 42. The holding device 3 is an electrostatic chuck that attracts and holds the substrate W by electrostatic attraction.

[0069] The ceramic sintered body 60 is a ceramic sintered body that is placed inside the through hole 23 of the substrate material 20. The ceramic sintered body 60 has a porous portion 31 and a cylindrical dense portion 32 located outside the porous portion 31. Compared to the ceramic sintered body 30A of the first embodiment, the ceramic sintered body 60 is larger in size relative to the through hole 23. Specifically, the difference between the outer diameter of the ceramic sintered body 60 and the inner size of the through hole 23 of the substrate material 20 is 0.005 mm to 0.05 mm, and a portion of the outer diameter of the ceramic sintered body 60 is larger than the inner diameter of the through hole 23 of the substrate material 20. In the holding device 3, the ceramic sintered body 60 is not fixed to the substrate material 20 by a bonding material. That is, the holding device 3 does not have the adhesive layer 33 of the holding device 1A of the first embodiment between the substrate material 20 and the ceramic sintered body 60. In this embodiment, the average linear thermal expansion coefficient of the material forming the ceramic sintered body 60 is greater than the average linear thermal expansion coefficient of the material forming the substrate 20 and the average linear thermal expansion coefficient of the material forming the base 10.

[0070] In the manufacturing method of the holding device 3 of this embodiment, in the fixing step following the projection formation step, the ceramic sintered body 60 is fixed to the aluminum nitride plate P20 by shrink-fitting. Specifically, for example, after heating the base 10 and the aluminum nitride plate P20 to a temperature of 100°C or higher, the ceramic sintered body 60 at room temperature or below is inserted into the through hole 23 through the opening 22. After the ceramic sintered body 60 is inserted into the through hole 23, as the temperature of the aluminum nitride plate P20 decreases, the aluminum nitride plate P20 shrinks, and the side surface of the ceramic sintered body 60 receives compressive stress from the shrinking aluminum nitride plate P20. As a result, the aluminum nitride plate P20 and the ceramic sintered body 60 become tightly attached.

[0071] As described above, in the holding device 3 of this embodiment, the ceramic sintered body 60, which has a porous portion 31 and a cylindrical dense portion 32 located outside the porous portion 31, has its end portion 302 extending to the inside of the flow path 11 inside the base 10. This prevents the inert gas flowing through the flow path 11 from coming into contact with the conductive film 42, thereby suppressing abnormal discharge. Furthermore, the ceramic sintered body 60 is located inside the through hole 23 via the opening 22. This allows the ceramic sintered body 60 to be attached to the substrate material 20 regardless of the shape of the flow path 11 in the base 10. Therefore, the design freedom of the holding device 3 equipped with the ceramic sintered body 60 that suppresses abnormal discharge can be improved.

[0072] Furthermore, according to the holding device 3 of this embodiment, the ceramic sintered body 60 has a dense portion 32 that is formed to cover the outer periphery of the porous portion 31, which has a relatively large porosity. As a result, the size of the ceramic sintered body 60 can be precisely matched to the size of the inside of the through hole 23, and thus the strength can be set to a certain level or higher when fixing to the substrate material 20 by shrink fitting.

[0073] Furthermore, according to the holding device 3 of this embodiment, the ceramic sintered body 60 is joined to the substrate material 20 for the substrate by shrink-fitting into the through hole 23 without using a bonding material. As a result, in the environment in which the holding device 3 is used, the generation of foreign matter originating from the bonding material and contamination of the substrate W by trace components contained in the bonding material can be suppressed.

[0074] Furthermore, according to the holding device 3 of this embodiment, the average linear thermal expansion coefficient of the material forming the ceramic sintered body 60 is greater than that of the material forming the substrate material 20 and the material forming the base 10. As a result, when the temperature of the holding device 3 rises during use, the ceramic sintered body 60 receives compressive stress from the through holes 23 and the inner walls of the flow channels 11, thereby improving the adhesion between the ceramic sintered body 60 and the through holes 23 and the inner walls of the flow channels 11. Consequently, the inert gas flowing through the flow channels 11 has difficulty passing between the base 10 and the ceramic sintered body 60, further suppressing the occurrence of abnormal discharges.

[0075] <Fourth Embodiment> Figure 12 is an enlarged cross-sectional view of the holding device 1B of the fourth embodiment. The holding device 1B of the fourth embodiment differs in the shape of the ceramic sintered body compared to the holding device 1A of the first embodiment (Figure 3).

[0076] The holding device 1B of the fourth embodiment comprises a base 10, a substrate material 20 for the substrate, a ceramic sintered body 30B, a joint 41, and a conductive film 42. The holding device 1B is an electrostatic chuck that holds the substrate W by electrostatic attraction.

[0077] The ceramic sintered body 30B is placed inside the through-hole 23 of the substrate material 20. The negative z-axis end 302 of the ceramic sintered body 30B extends to the inside of the flow channel 11. The ceramic sintered body 30B is made of a material mainly composed of alumina and therefore has insulating properties.

[0078] The ceramic sintered body 30B has a porous portion 31 and a cylindrical dense portion 32 located outside the porous portion 31. In this embodiment, the ceramic sintered body 30B and the substrate material 20 are joined by an adhesive layer 33. As shown in Figure 12, the end portion 301 of the ceramic sintered body 30B on the side opposite to the base 10 (the positive side in the z-axis direction) is located on the mounting surface 21 side of the opening surface 20e. As a result, an annular groove 20h is formed between the inside of the opening 22, which has a recessed shape relative to the mounting surface 21, and the outside of the dense portion 32 of the ceramic sintered body 30B.

[0079] As described above, with the holding device 1B of this embodiment, the end portion 302 of the ceramic sintered body 30B extends inside the flow channel 11 within the base 10. This prevents the inert gas flowing through the flow channel 11 from coming into contact with the conductive film 42, thereby suppressing abnormal discharge. Furthermore, since the ceramic sintered body 30B is positioned inside the through hole 23 via the opening 22, the ceramic sintered body 30B can be attached to the substrate material 20 regardless of the shape of the flow channel 11 in the base 10. Therefore, the design flexibility of the holding device 1B can be improved.

[0080] Furthermore, according to the holding device 1B of this embodiment, a groove 20h is formed around the end portion 302 of the ceramic sintered body 30B. Since airflow flows through the porous portion 31 of the ceramic sintered body 30B in the groove 20h, etching residue generated from the substrate W in a plasma etching process can be collected in the groove 20h by the airflow through the porous portion 31. In addition, since the distance between the substrate W placed on the mounting surface 21 and the ceramic sintered body 30B is smaller than that of the holding device 1A of the first embodiment, the occurrence of abnormal discharge in a plasma etching process can be suppressed.

[0081] <Fifth Embodiment> Figure 13 is an enlarged cross-sectional view of the holding device 1C of the fifth embodiment. The holding device 1C of the fifth embodiment differs in the shape of the ceramic sintered body from the holding device 1A of the first embodiment (Figure 3).

[0082] The holding device 1C of the fifth embodiment comprises a base 10, a substrate material 20 for the substrate, a ceramic sintered body 30C, a joint 41, and a conductive film 42. The holding device 1C is an electrostatic chuck that attracts and holds the substrate W by electrostatic attraction.

[0083] The ceramic sintered body 30C is placed inside the through-hole 23 of the substrate material 20. The negative z-axis end 302 of the ceramic sintered body 30C extends to the inside of the flow channel 11. The ceramic sintered body 30C has insulating properties because it is formed from a material mainly composed of alumina.

[0084] The ceramic sintered body 30C has a porous portion 31 and a cylindrical dense portion 32 located outside the porous portion 31. In this embodiment, the ceramic sintered body 30C and the substrate material 20 are joined by an adhesive layer 33. As shown in Figure 13, the end portion 301 of the ceramic sintered body 30C on the side opposite to the base 10 (the positive side in the z-axis direction) is located closer to the mounting surface 21 than the opening surface 20e, and the end face of the end portion 301 has a V-shaped curved surface. As a result, an annular groove 20i is formed between the inside of the opening 22, which has a recessed shape relative to the mounting surface 21, and the outside of the dense portion 32 of the ceramic sintered body 30C.

[0085] As described above, in the holding device 1C of this embodiment, the end portion 302 of the ceramic sintered body 30C extends inside the flow channel 11 within the base 10. This prevents the inert gas flowing through the flow channel 11 from coming into contact with the conductive film 42, thereby suppressing abnormal discharge. Furthermore, since the ceramic sintered body 30C is positioned inside the through hole 23 via the opening 22, the ceramic sintered body 30C can be attached to the substrate material 20 regardless of the shape of the flow channel 11 in the base 10. Therefore, the design flexibility of the holding device 1C can be improved.

[0086] Furthermore, according to the holding device 1C of this embodiment, a groove 20i is formed around the end portion 302 of the ceramic sintered body 30C. Since airflow flows through the porous portion 31 of the ceramic sintered body 30C in the groove 20i, etching residue generated from the substrate W in a plasma etching process can be collected in the groove 20i by the airflow through the porous portion 31. In addition, since the distance between the substrate W placed on the mounting surface 21 and the ceramic sintered body 30C is smaller than that of the holding device 1A of the first embodiment, the occurrence of abnormal discharge in a plasma etching process can be suppressed.

[0087] <Sixth Embodiment> Figure 14 is an enlarged cross-sectional view of the holding device 1D of the sixth embodiment. The holding device 1D of the sixth embodiment differs in the shape of the ceramic sintered body compared to the holding device 1A of the first embodiment (Figure 3).

[0088] The holding device 1D of the sixth embodiment comprises a base 10, a substrate material 20 for the substrate, a ceramic sintered body 30D, a joint 41, and a conductive film 42. The holding device 1D is an electrostatic chuck that attracts and holds the substrate W by electrostatic attraction.

[0089] The ceramic sintered body 30D is placed inside the through-hole 23 of the substrate material 20. The negative z-axis end 302 of the ceramic sintered body 30D extends to the inside of the flow channel 11. The ceramic sintered body 30D is made of a material mainly composed of alumina and therefore has insulating properties.

[0090] The ceramic sintered body 30D has a porous portion 31 and a cylindrical dense portion 32 located outside the porous portion 31. In this embodiment, the ceramic sintered body 30D and the substrate material 20 are joined by an adhesive layer 33. In this embodiment, the end portion 301 of the ceramic sintered body 30D is located on the base 10 side of the opening surface 20e. As shown in Figure 14, the end face of the end portion 301 of the ceramic sintered body 30D on the side opposite to the base 10 (the positive side in the z-axis direction) has a valley-shaped curved surface.

[0091] In the manufacturing method of the holding device 1D of this embodiment, the order of the protrusion formation step, in which a plurality of protrusions 20d are formed on the aluminum nitride plate P20, and the fixing step, in which the ceramic sintered body 30A is fixed to the aluminum nitride plate P20, is reversed compared to the manufacturing method of the holding device 1A of the first embodiment. Specifically, the fixing step, in which the ceramic sintered body 30D is fixed to the aluminum nitride plate P20, is performed first, followed by the protrusion formation step, in which a plurality of protrusions 20d are formed on the aluminum nitride plate P20. When the protrusions 20d are formed using sandblasting in the protrusion formation step, the end faces of the ends 301 of the porous portion 31, which have relatively low material strength, are polished by sandblasting, resulting in a valley-shaped curved surface.

[0092] As described above, according to the holding device 1D of this embodiment, the end portion 302 of the ceramic sintered body 30D extends inside the flow channel 11 within the base 10. This prevents the inert gas flowing through the flow channel 11 from coming into contact with the conductive film 42, thereby suppressing abnormal discharge. Furthermore, since the ceramic sintered body 30D is positioned inside the through hole 23 via the opening 22, the ceramic sintered body 30D can be attached to the substrate material 20 regardless of the shape of the flow channel 11 in the base 10. Therefore, the design flexibility of the holding device 1C can be improved.

[0093] Furthermore, according to the holding device 1D of this embodiment, the porous portion 31 of the ceramic sintered body 30C has a valley-shaped curved surface at the end face 301 opposite to the base 10. The valley-shaped curved surface of the porous portion 31 is processed in the manufacturing method of the holding device 1D when a plurality of protrusions 20d are formed on the aluminum nitride plate P20 using sandblasting, as described above. This simplifies some of the steps included in the manufacturing method of the holding device 1D.

[0094] <Seventh Embodiment> Figure 15 is an enlarged cross-sectional view of the holding device 1E of the seventh embodiment. The holding device 1E of the seventh embodiment differs in the shape of the ceramic sintered body compared to the holding device 1A of the first embodiment (Figure 3).

[0095] The seventh embodiment of the holding device 1E comprises a base 10, a substrate material 20 for the substrate, a ceramic sintered body 30E, a joint 41, and a conductive film 42. The holding device 1E is an electrostatic chuck that holds the substrate W by electrostatic attraction.

[0096] The ceramic sintered body 30E is placed inside the through-hole 23 of the substrate material 20. The negative z-axis end 302 of the ceramic sintered body 30E extends to the inside of the flow channel 11. The ceramic sintered body 30E is made of a material mainly composed of alumina and therefore has insulating properties.

[0097] The ceramic sintered body 30E has a porous portion 31 and a cylindrical dense portion 32 located outside the porous portion 31. In this embodiment, the ceramic sintered body 30E and the substrate material 20 are joined by an adhesive layer 33. In the cross-section shown in Figure 15, the ceramic sintered body 30E is formed such that its width decreases from the mounting surface 21 side toward the base 10 side.

[0098] As described above, in the holding device 1E of this embodiment, the end portion 302 of the ceramic sintered body 30E extends inside the flow channel 11 within the base 10. This suppresses contact between the inert gas flowing through the flow channel 11 and the conductive film 42, thereby suppressing abnormal discharge. Furthermore, since the ceramic sintered body 30E is positioned inside the through hole 23 via the opening 22, the ceramic sintered body 30E can be attached to the substrate material 20 regardless of the shape of the flow channel 11 in the base 10. Therefore, the design flexibility of the holding device 1E can be improved.

[0099] Furthermore, according to the holding device 1E of this embodiment, the ceramic sintered body 30E is formed such that its width decreases as it moves from the mounting surface 21 side toward the base 10 side. This improves the adhesion between the inside of the through hole 23 and the outside of the ceramic sintered body 30E when the substrate material 20 and the ceramic sintered body 30E are joined by the adhesive layer 33. Therefore, leakage of inert gas in the adhesive layer 33 can be suppressed.

[0100] <Eighth Embodiment> Figure 16 is an enlarged cross-sectional view of the holding device 1F of the eighth embodiment. The holding device 1F of the eighth embodiment differs from the holding device 1A of the first embodiment (Figure 3) in that a communication hole is formed in the porous portion of the ceramic sintered body, connecting the inside of the flow channel to the outside of the holding device.

[0101] The holding device 1F of the eighth embodiment comprises a base 10, a substrate material 20 for the substrate, a ceramic sintered body 30F, a joint 41, and a conductive film 42. The holding device 1F is an electrostatic chuck that attracts and holds the substrate W by electrostatic attraction.

[0102] The ceramic sintered body 30F is placed inside the through-hole 23 of the substrate material 20. The negative z-axis end 302 of the ceramic sintered body 30F extends to the inside of the flow channel 11. The ceramic sintered body 30F has insulating properties because it is formed from a material mainly composed of alumina.

[0103] The ceramic sintered body 30F has a porous portion 31 and a cylindrical dense portion 32 located outside the porous portion 31. In this embodiment, the ceramic sintered body 30F and the substrate material 20 are joined by an adhesive layer 33. As shown in Figure 16, the porous portion 31 of the ceramic sintered body 30F has a communication hole 31a that connects the inside of the flow channel 11 to the outside of the holding device 1F. In the ceramic sintered body 30F of this embodiment, the inner diameter of the communication hole 31a is 0.1 mm or less.

[0104] As described above, with the holding device 1F of this embodiment, the end portion 302 of the ceramic sintered body 30F extends inside the flow channel 11 within the base 10. This prevents the inert gas flowing through the flow channel 11 from coming into contact with the conductive film 42, thereby suppressing abnormal discharge. Furthermore, since the ceramic sintered body 30F is positioned inside the through hole 23 via the opening 22, the ceramic sintered body 30F can be attached to the substrate material 20 regardless of the shape of the flow channel 11 in the base 10. Therefore, the design flexibility of the holding device 1F can be improved.

[0105] Furthermore, according to the holding device 1F of this embodiment, the ceramic sintered body 30F has a communication hole 31a formed in the porous portion 31 that connects the inside of the flow path 11 and the outside of the holding device 1F. This makes it easier for inert gas to move between the inside of the flow path 11 and the outside of the holding device 1F through the communication hole 31a. In addition, since the inner diameter of the communication hole 31a is 0.1 mm or less, it is possible to suppress the occurrence of abnormal discharge via the inert gas passing through the communication hole 31a. As a result, it is possible to increase the flow rate of inert gas passing through the ceramic sintered body 30F while suppressing the occurrence of abnormal discharge.

[0106] <Ninth Embodiment> Figure 17 is an enlarged cross-sectional view of the holding device 1G of the ninth embodiment. The holding device 1G of the ninth embodiment differs from the holding device 1A of the first embodiment (Figure 3) in that the porous portion of the ceramic sintered body has a recessed portion.

[0107] The holding device 1G of the ninth embodiment comprises a base 10, a substrate material 20 for the substrate, a ceramic sintered body 30G, a joint 41, and a conductive film 42. The holding device 1G is an electrostatic chuck that attracts and holds the substrate W by electrostatic attraction.

[0108] The ceramic sintered body 30G is placed inside the through-hole 23 of the substrate material 20. The negative z-axis end 302 of the ceramic sintered body 30G extends to the inside of the flow channel 11. The ceramic sintered body 30G has insulating properties because it is formed from a material mainly composed of alumina.

[0109] The ceramic sintered body 30G has a porous portion 31 and a cylindrical dense portion 32 located outside the porous portion 31. In this embodiment, the ceramic sintered body 30G and the substrate material 20 are joined by an adhesive layer 33. As shown in Figure 17, the porous portion 31 of the ceramic sintered body 30G has a recessed portion 31b formed at the negative end in the z-axis direction.

[0110] As described above, in the holding device 1G of this embodiment, the end portion 302 of the ceramic sintered body 30G extends inside the flow channel 11 within the base 10. This prevents the inert gas flowing through the flow channel 11 from coming into contact with the conductive film 42, thereby suppressing abnormal discharge. Furthermore, since the ceramic sintered body 30G is positioned inside the through hole 23 via the opening 22, the ceramic sintered body 30G can be attached to the substrate material 20 regardless of the shape of the flow channel 11 in the base 10. Therefore, the design flexibility of the holding device 1G can be improved.

[0111] Furthermore, in the holding device 1G of this embodiment, the porous portion 31 of the ceramic sintered body 30G has a recessed portion 31b formed at the negative end in the z-axis direction. As a result, the pressure loss of the inert gas passing through the porous portion 31 is smaller than in the first embodiment, making it easier for the inert gas to move between the inside of the flow path 11 and the outside of the holding device 1G. Therefore, it is possible to increase the flow rate of the inert gas passing through the ceramic sintered body 30G while suppressing the occurrence of abnormal discharge.

[0112] <Tenth Embodiment> Figure 18 is an enlarged cross-sectional view of the holding device 1H of the tenth embodiment. The holding device 1H of the tenth embodiment differs from the holding device 1A of the first embodiment (Figure 3) in that the porous portion of the ceramic sintered body has a recessed portion.

[0113] The holding device 1H of the tenth embodiment comprises a base 10, a substrate material 20 for the substrate, a ceramic sintered body 30H, a joint 41, and a conductive film 42. The holding device 1H is an electrostatic chuck that attracts and holds the substrate W by electrostatic attraction.

[0114] The ceramic sintered body 30H is placed inside the through-hole 23 of the substrate material 20. The negative z-axis end 302 of the ceramic sintered body 30H extends to the inside of the flow channel 11. The ceramic sintered body 30H has insulating properties because it is formed from a material mainly composed of alumina.

[0115] The ceramic sintered body 30H has a porous portion 31 and a cylindrical dense portion 32 located outside the porous portion 31. In this embodiment, the ceramic sintered body 30H and the substrate material 20 are joined by an adhesive layer 33. As shown in Figure 18, the porous portion 31 of the ceramic sintered body 30H has a recessed portion 31c formed at the positive end in the z-axis direction.

[0116] As described above, in the holding device 1H of this embodiment, the end portion 302 of the ceramic sintered body 30H extends inside the flow channel 11 within the base 10. This prevents the inert gas flowing through the flow channel 11 from coming into contact with the conductive film 42, thereby suppressing abnormal discharge. Furthermore, since the ceramic sintered body 30H is positioned inside the through hole 23 via the opening 22, the ceramic sintered body 30H can be attached to the substrate material 20 regardless of the shape of the flow channel 11 in the base 10. Therefore, the design flexibility of the holding device 1H can be improved.

[0117] Furthermore, in the holding device 1H of this embodiment, the porous portion 31 of the ceramic sintered body 30H has a recessed portion 31c formed at the positive end in the z-axis direction. As a result, the pressure loss of the inert gas passing through the porous portion 31 is smaller than in the first embodiment, making it easier for the inert gas to move between the inside of the flow path 11 and the outside of the holding device 1H. Therefore, it is possible to increase the flow rate of the inert gas passing through the ceramic sintered body 30H while suppressing the occurrence of abnormal discharge.

[0118] <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.

[0119] [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.

[0120] [Differentiation 2] In the above-described embodiment, the holding device comprises a base 10, a substrate material 20, a ceramic sintered body, a joint 41, and a conductive film 42. However, the configuration of the holding device is not limited to this. For example, a layer different from the joint 41 and the conductive film 42 may be placed between the base 10 and the substrate material 20. Also, although the base 10 and the substrate material 20 are each described as a single plate-shaped member as shown in Figure 2, they may be formed by stacking multiple plate-shaped members.

[0121] [Difference 3] In the above-described embodiment, in a cross-section including the central axis of the holding device, the length of the ceramic sintered body in the stacking direction between the base and the substrate material was set to 1.5 times or more the thickness of the substrate material in the stacking direction. The length of the ceramic sintered body may be less than 1.5 times the thickness of the substrate material in the stacking direction. At the portion where the through hole and the flow path are connected, it is sufficient that the conductive film is covered by the ceramic sintered body and that the inert gas is arranged in such a way that it is difficult for it to come into contact with the conductive film.

[0122] [Differentiation Example 4] In the above-described embodiment, the ceramic sintered body is positioned on the base side of the mounting surface or reference surface. However, the position of the ceramic sintered body is not limited to this. By positioning the ceramic sintered body on the base side of the mounting surface or reference surface, contact between the ceramic sintered body and the substrate is reduced, allowing for relatively large design tolerances for the holding device. Furthermore, the position of the positive end face in the z-axis direction of the ceramic sintered body is assumed to be substantially coplanar with the opening surface 20e. However, the position of the positive end face in the z-axis direction of the ceramic sintered body may be located inside the through hole; for example, the ceramic sintered body may be embedded inside the through hole.

[0123] [Difference 5] In the above embodiment, the average linear thermal expansion coefficient of the material forming the ceramic sintered body was assumed to be greater than that of the material forming the substrate 20 and the material forming the base 10. However, the relationship between the average linear thermal expansion coefficients is not limited to this. By making the average linear thermal expansion coefficient of the material forming the ceramic sintered body greater than that of the material forming the substrate 20 and the material forming the base 10, the ceramic sintered body receives compressive stress from the through-holes 23 and the inner walls of the flow channels 11 when the temperature of the holding device rises, thereby improving the adhesion between the ceramic sintered body and the through-holes 23 and the inner walls of the flow channels 11.

[0124] [Modification 6] In the above-described embodiment, the opening in the substrate material 20 is recessed relative to the reference surface 20c, as shown in Figure 3 and other figures. The shape of the opening is not limited to this, and any opening into which a ceramic sintered body can be inserted is acceptable.

[0125] [Difference 7] In the above-described embodiment, it is assumed that a stepped surface 10a is formed in the flow channel 11 of the base 10, and that the ceramic sintered body is arranged in contact with the stepped surface 10a. However, the stepped surface is not required.

[0126] Figure 19 is an enlarged cross-sectional view of a modified example of the holding device 1A of the first embodiment. In the holding device 1A shown in Figure 19, the second flow path 11c of the flow path 11 is formed larger on the inside than the first flow path 11b and the second flow path 11d so that the ceramic sintered body 30A can be inserted. That is, a stepped surface that contacts the end face of the negative z-axis end 302 of the ceramic sintered body 30A is not formed. In such a case, by making the length L of the ceramic sintered body 30A longer than the thickness D of the substrate material 20, and pushing the end face of the positive z-axis end 301 of the ceramic sintered body 30A toward the base 10 side beyond the opening surface 20e, it is possible to suppress the inert gas from contacting the conductive film 42. Therefore, the design freedom of the holding device 1A equipped with a ceramic sintered body 30A that suppresses abnormal discharge can be improved.

[0127] [Differentiation 8] In each of the 4th to 6th and 8th to 10th embodiments, the ceramic sintered body and the substrate material 20 are joined by an adhesive layer 33. In these embodiments, the ceramic sintered body and the substrate material 20 do not necessarily have to be joined by a bonding material. They may be fixed by press-fitting, as used in the manufacturing method of the retaining device 2 of the second embodiment, or by shrink-fitting, as used in the manufacturing method of the retaining device 3 of the third embodiment.

[0128] 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.

[0129] <Application Example 1> A holding device for holding a substrate, A base having a fluid channel through which fluid flows, including a bent section inside the channel, A plate-shaped substrate for a substrate, which is placed on the base, having a mounting surface on which the substrate is placed, an opening formed in the mounting surface, and a through hole that connects the flow path of the base to the opening, A ceramic sintered body disposed inside the through hole, comprising a porous portion and a cylindrical dense portion disposed outside the porous portion, The end of the ceramic sintered body is characterized in that it extends to the inside of the flow channel. holding device. <Application Example 2> The holding device described in Application Example 1, The substrate material and the ceramic sintered body are characterized in that they are not joined by a bonding material. holding device. <Application Example 3> A holding device as described in Application Example 1 or Application Example 2, The ceramic sintered body is positioned on the base side of the mounting surface described above, In a cross-section including the central axis of the holding device, The length of the ceramic sintered body in the stacking direction between the base and the substrate is characterized by being 1.5 times or more the thickness of the substrate in the stacking direction. holding device. <Application Example 4> A holding device described in any one of the examples from Application Example 1 to Application Example 3, The substrate material for the substrate has a reference surface and a plurality of protrusions erected on the reference surface. The mounting surface is formed by the tip surfaces of each of the plurality of protrusions, The ceramic sintered body is positioned on the base side of the reference surface, holding device. <Application Example 5> A holding device described in any one of Application Examples 1 to 4, The aforementioned opening has a recessed shape relative to the aforementioned mounting surface, and an opening surface is formed that is located on the base side of the aforementioned mounting surface. The end of the ceramic sintered body opposite to the base is characterized in that it is located on the side of the mounting surface described above, rather than on the opening surface. holding device. <Application Example 6> A holding device described in any one of Application Examples 1 to 5, The end face of the ceramic sintered body opposite to the base is characterized by having a V-shaped curved surface. holding device. <Application Example 7> A holding device described in any one of the examples from Application Example 1 to Application Example 6, The end face of the porous portion opposite to the base is characterized by having a valley-shaped curved surface. holding device. <Application Example 8> A holding device described in any one of Application Examples 1 to 7, The substrate material and the ceramic sintered body are joined together by a bonding material. In a cross-section including the central axis of the holding device, The ceramic sintered body is characterized in that its width decreases as it moves from the mounting surface side toward the base side. holding device. <Application Example 9> A holding device described in any one of Application Examples 1 to 8, The porous portion has a communication hole that connects the inside of the flow path to the outside of the holding device. The inner diameter of the aforementioned communication hole is characterized by being 0.1 mm or less. holding device. <Application Example 10> A holding device described in any one of the examples from Application Example 1 to Application Example 9, The porous portion is characterized by having a recessed portion at at least one of the ends on the base side and the end on the opposite side of the base. holding device. <Application Example 11> A holding device described in any one of the examples from Application Example 1 to Application Example 10, The substrate material for the substrate is formed from a material mainly composed of aluminum nitride or alumina. The base is characterized by being a sintered body formed from a material mainly composed of silicon carbide, or a sintered body formed from a material containing silicon carbide and having a thermal conductivity of 70 W / mK or higher. holding device. <Application Example 12> A holding device described in any one of Application Examples 1 to 11, The average linear thermal expansion coefficient of the material forming the ceramic sintered body is characterized in that it is greater than the average linear thermal expansion coefficient of the material forming the substrate base and the average linear thermal expansion coefficient of the material forming the base. holding device. <Application Example 13> A holding device described in any one of Application Examples 1 to 12, The aforementioned ceramic sintered body is characterized by being formed from a material mainly composed of alumina. holding device. <Application Example 14> A base having a fluid channel through which fluid flows, including a bent section inside the channel, A plate-shaped substrate for a substrate, which is placed on the base, having a mounting surface on which the substrate is placed, an opening formed in the mounting surface, and a through hole that connects the flow path of the base to the opening, A ceramic sintered body disposed inside the through hole, comprising a porous portion and a cylindrical dense portion disposed outside the porous portion, A method for manufacturing a holding device in which the end of the ceramic sintered body reaches the inside of the flow path, Preparation steps for preparing the base, the substrate material for the substrate, and the ceramic sintered body, A bonding step of joining the base and the substrate material for the substrate, The invention is characterized by comprising, after the bonding step, a fixing step of inserting the ceramic sintered body into the through hole through the opening in the substrate material and fixing the ceramic sintered body to the substrate material. A method for manufacturing a holding device. <Application Example 15> A method for manufacturing a holding device as described in Application Example 14, In the preparation step described above, prepare a conductive film, The bonding process is characterized in that the substrate material and the base are bonded together such that the conductive film is located between the substrate material and the base. A method for manufacturing a holding device. [Explanation of Symbols]

[0130] 1A,1B,1C,1D,1E,1F,1G,1H,2,3...Holding device 10…Base 11…flow channel 11a...Bending part 20...Base material for substrate 20c…Reference plane 20d…Protrusion 20e…Opening surface 20f…Tip surface 21… Mounting surface 22…Opening 23…Through hole 30A, 30B, 30C, 30D, 30E, 30F, 30G, 30H, 50, 60… Ceramic sintered bodies 301, 302… (ends of ceramic sintered bodies) 31...Porous part 31a... (Communication holes in the porous part) 31b, 31c... recessed area 32…Dense part 42... Conductive film C1…Central axis L...Length of the ceramic sintered body D...Thickness of substrate material for circuit boards

Claims

1. A holding device for holding a substrate, A base having a fluid channel through which fluid flows, including a bent section inside the channel, A plate-shaped substrate for a substrate, which is placed on the base, having a mounting surface on which the substrate is placed, an opening formed in the mounting surface, and a through hole that connects the flow path of the base to the opening, A ceramic sintered body disposed inside the through hole, comprising a porous portion and a cylindrical dense portion disposed outside the porous portion, The end of the ceramic sintered body is characterized in that it extends to the inside of the flow channel. holding device.

2. A holding device according to claim 1, The substrate material and the ceramic sintered body are characterized in that they are not joined by a bonding material. holding device.

3. A holding device according to claim 1 or claim 2, The ceramic sintered body is positioned on the base side of the mounting surface described above, In a cross-section including the central axis of the holding device, The length of the ceramic sintered body in the stacking direction between the base and the substrate is characterized by being 1.5 times or more the thickness of the substrate in the stacking direction. holding device.

4. A holding device according to claim 1 or claim 2, The substrate material for the substrate has a reference surface and a plurality of protrusions erected on the reference surface. The mounting surface is formed by the tip surfaces of each of the plurality of protrusions, The ceramic sintered body is characterized in that it is positioned on the base side of the reference surface. holding device.

5. A holding device according to claim 1 or claim 2, The aforementioned opening has a recessed shape relative to the aforementioned mounting surface, and an opening surface is formed that is located on the base side of the aforementioned mounting surface. The end of the ceramic sintered body opposite to the base is characterized in that it is located on the side of the mounting surface described above, rather than on the opening surface. holding device.

6. A holding device according to claim 5, The end face of the ceramic sintered body opposite to the base is characterized by having a V-shaped curved surface. holding device.

7. A holding device according to claim 1 or claim 2, The end face of the porous portion opposite to the base is characterized by having a valley-shaped curved surface. holding device.

8. A holding device according to claim 1 or claim 2, The substrate material and the ceramic sintered body are joined together by a bonding material. In a cross-section including the central axis of the holding device, The ceramic sintered body is characterized in that its width decreases as it moves from the mounting surface side toward the base side. holding device.

9. A holding device according to claim 1 or claim 2, The porous portion has a communication hole that connects the inside of the flow path to the outside of the holding device. The inner diameter of the aforementioned communication hole is characterized by being 0.1 mm or less. holding device.

10. A holding device according to claim 1 or claim 2, The porous portion is characterized by having a recessed portion at at least one of the ends on the base side and the end on the opposite side of the base. holding device.

11. A holding device according to claim 1 or claim 2, The substrate material for the substrate is formed from a material mainly composed of aluminum nitride or alumina. The base is characterized by being a sintered body formed from a material mainly composed of silicon carbide, or a sintered body formed from a material containing silicon carbide and having a thermal conductivity of 70 W / mK or higher. holding device.

12. A holding device according to claim 1 or claim 2, The average linear thermal expansion coefficient of the material forming the ceramic sintered body is characterized in that it is greater than the average linear thermal expansion coefficient of the material forming the substrate for the substrate and the average linear thermal expansion coefficient of the material forming the base. holding device.

13. A holding device according to claim 1 or claim 2, The aforementioned ceramic sintered body is characterized by being formed from a material mainly composed of alumina. holding device.

14. A base having a fluid channel through which fluid flows, including a bent section inside the channel, A plate-shaped substrate for a substrate, which is placed on the base, having a mounting surface on which the substrate is placed, an opening formed in the mounting surface, and a through hole that connects the flow path of the base to the opening, A ceramic sintered body disposed inside the through hole, comprising a porous portion and a cylindrical dense portion disposed outside the porous portion, A method for manufacturing a holding device in which the end of the ceramic sintered body reaches the inside of the flow path, Preparation steps for preparing the base, the substrate material for the substrate, and the ceramic sintered body, A bonding step of joining the base and the substrate material for the substrate, The invention is characterized by comprising, after the bonding step, a fixing step of inserting the ceramic sintered body into the through hole through the opening in the substrate material and fixing the ceramic sintered body to the substrate material. A method for manufacturing a holding device.

15. A method for manufacturing a holding device according to claim 14, In the preparation step described above, prepare a conductive film, The bonding process is characterized in that the substrate material and the base are bonded together such that the conductive film is located between the substrate material and the base. A method for manufacturing a holding device.

Images