Electrostatic chuck

Abstract

To provide an electrostatic chuck capable of preventing damage or the like in a connection part between a heater unit and a terminal.SOLUTION: An electrostatic chuck 10 comprises: a heater unit 300; a base plate 200 for supporting the heater unit 300; and a bonding layer 420 that bonds to between the heater unit 300 and the base plate 200. A terminal 390 projected toward the base plate 200 side from the heater unit 300 is housed in an inner side of a penetration hole 230 formed in the base plate 200. In the inner side of the penetration hole 230, a support member 500 for supporting the terminal 390 from a circumference is arranged. In the circumference of a nearest part on the heater unit 300 side from the terminal 390, a space SP2 is formed. In the electrostatic chuck 10, one part of the bonding layer 420 is entered into the space SP2 to support the terminal 390 with the support member 500.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] For example, in a semiconductor manufacturing apparatus such as an etching apparatus, an electrostatic chuck is provided as a device for attracting and holding a substrate such as a silicon wafer to be processed. The electrostatic chuck includes a dielectric substrate provided with an attracting electrode and a base plate supporting the dielectric substrate, which are joined together. When a voltage is applied to the attracting electrode, an electrostatic force is generated, and the substrate placed on the dielectric substrate is attracted and held. When the substrate is being processed in the semiconductor manufacturing apparatus, the dielectric substrate is cooled by the base plate. This allows the temperature of the substrate placed on the dielectric substrate to be maintained at an appropriate temperature.

[0003] During the processing of a substrate, it is required to make the temperature distribution in the surface of the substrate as uniform as possible. In order to adjust the temperature distribution in the surface of the substrate with high accuracy, electrostatic chucks equipped with heaters have been developed in recent years and have already been put to practical use. The heater may be provided inside the dielectric substrate, or may be provided between the dielectric substrate and the base plate in a unitized state, as described in, for example, Patent Document 1 below. Considering that the dielectric substrate with a built-in heater can be regarded as a "heater unit" in its entirety, in either of the above cases, it can be said that the base plate is joined to the heater unit. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-197485 Summary of the Invention [Problem to be solved by the invention]

[0005] The heater unit is provided with a terminal for receiving a power supply from an external source, and the terminal protrudes outward and is accommodated, for example, inside a through hole formed in the base plate.

[0006] When processing a substrate, the temperature of each part of the electrostatic chuck rises. At this time, stress may be applied to the terminal, particularly to the part connected to the heater unit, due to differences in thermal expansion of each part. Depending on the magnitude of the stress, there is a risk of damage or the like occurring at the connection part between the heater unit and the terminal.

[0007] The present invention has been made in consideration of the above problems, and an object of the present invention is to provide an electrostatic chuck that can prevent damage, etc., to the connection portion between the heater unit and the terminal. [Means for solving the problem]

[0008] In order to solve the above problems, an electrostatic chuck according to the present invention includes a heater unit that generates heat by receiving power from an external source, a base plate that supports the heater unit, and a bonding layer that bonds the heater unit and the base plate. A terminal that protrudes from the heater unit toward the base plate is accommodated inside a through hole formed in the base plate. A support member that supports the terminal from the periphery is disposed inside the through hole. A space is formed around the portion of the terminal that is closest to the heater unit. In this electrostatic chuck, a part of the bonding layer enters the space and supports the terminal together with the support member.

[0009] In an electrostatic chuck having such a configuration, the base portions of the terminals protruding from the heater unit are supported and reinforced by the bonding layer that has entered the space, thereby making it possible to prevent damage to the connection portions between the heater unit and the terminals. Effect of the Invention

[0010] According to the present invention, it is possible to provide an electrostatic chuck that can prevent damage to the terminals of the heater unit. [Brief description of the drawings]

[0011] [Figure 1] 1 is a cross-sectional view illustrating a schematic configuration of an electrostatic chuck according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an exploded view showing a schematic configuration of a heater unit. [Diagram 3] FIG. 2 is an enlarged view of a portion of the configuration of FIG. [Figure 4] 10A and 10B are diagrams illustrating a state in which a terminal is inserted into an inner side of a support member when assembling the electrostatic chuck. [Diagram 5] FIG. 1 is a cross-sectional view illustrating a schematic configuration of an electrostatic chuck according to a comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, the present embodiment will be described with reference to the accompanying drawings. In order to facilitate understanding of the description, the same components in each drawing are denoted by the same reference numerals as much as possible, and duplicated description will be omitted.

[0013] The electrostatic chuck 10 according to this embodiment is configured to electrostatically attract and hold a substrate W to be processed inside a semiconductor manufacturing apparatus (not shown), such as an etching apparatus. The substrate W is, for example, a silicon wafer. The electrostatic chuck 10 may be used in an apparatus other than a semiconductor manufacturing apparatus.

[0014] 1 is a schematic cross-sectional view showing the configuration of an electrostatic chuck 10 in a state in which the electrostatic chuck 10 attracts and holds a substrate W. The electrostatic chuck 10 includes a dielectric substrate 100, a base plate 200, and a heater unit 300.

[0015] The dielectric substrate 100 is a substantially disk-shaped member made of a sintered ceramic body. The dielectric substrate 100 contains, for example, high-purity aluminum oxide (Al2O3), but may contain other materials. The purity, type, and additives of the ceramics in the dielectric substrate 100 can be appropriately set in consideration of the plasma resistance and other properties required of the dielectric substrate 100 in semiconductor manufacturing equipment.

[0016] 1 of the dielectric substrate 100 is a "mounting surface" on which the substrate W is mounted. Also, a lower surface 120 of the dielectric substrate 100 in FIG. 1 is a "bonded surface" that is bonded to the heater unit 300 via a bonding layer 410. The viewpoint when the electrostatic chuck 10 is viewed from the side of the surface 110 along a direction perpendicular to the surface 110 will hereinafter be referred to as a "top view".

[0017] An adsorption electrode 130 is embedded inside the dielectric substrate 100. The adsorption electrode 130 is a thin flat layer made of a metal material such as tungsten, and is embedded in the dielectric substrate 100 in a state parallel to the surface 110. The material of the adsorption electrode 130 may be tungsten, molybdenum, platinum, palladium, or the like. When a voltage is applied to the adsorption electrode 130 from the outside via a power supply path (not shown), an electrostatic force is generated between the surface 110 and the substrate W, thereby adsorbing and holding the substrate W. As the configuration of the power supply path, various known configurations can be adopted. The adsorption electrode 130 may be provided as a so-called "monopolar" electrode, as in this embodiment, or may be provided as two so-called "bipolar" electrodes.

[0018] 1, a space SP1 is formed between the dielectric substrate 100 and the substrate W. When a process such as etching is performed in the semiconductor manufacturing apparatus, helium gas for temperature adjustment is supplied from the outside to the space SP1 through a gas hole (not shown). By providing helium gas between the dielectric substrate 100 and the substrate W, the thermal resistance between them is adjusted, and the temperature of the substrate W is thereby maintained at an appropriate temperature. The gas for temperature adjustment supplied to the space SP1 may be a type of gas other than helium.

[0019] A seal ring 111, dots 112, etc. are provided on a surface 110 that is a mounting surface, and the above-mentioned space SP1 is formed around these.

[0020] The seal ring 111 is a wall that divides the space SP1 at the outermost position. The upper end surface of the seal ring 111 forms part of the surface 110 and abuts against the substrate W. Note that a plurality of seal rings 111 may be provided to divide the space SP1. With this configuration, it is possible to individually adjust the pressure of the helium gas in each space SP1 and make the surface temperature distribution of the substrate W during processing more uniform.

[0021] 1, the portion marked with the reference symbol "116" is the bottom surface of the space SP1. Hereinafter, this portion will also be referred to as the "bottom surface 116." The seal ring 111, together with the dots 112 described below, is formed as a result of digging down a part of the surface 110 to the position of the bottom surface 116.

[0022] The dots 112 are circular protrusions protruding from the bottom surface 116. A plurality of dots 112 are provided and are distributed approximately evenly on the mounting surface of the dielectric substrate 100. The upper end of each dot 112 forms part of the surface 110 and abuts against the substrate W. By providing a plurality of such dots 112, bending of the substrate W is suppressed.

[0023] The base plate 200 is a substantially disk-shaped member that supports the dielectric substrate 100 and the heater unit 300. The base plate 200 is formed of a metal material such as aluminum. The upper surface 210 of the base plate 200 in FIG. 1 is a "bonded surface" that is bonded to the heater unit 300 via a bonding layer 420.

[0024] A coolant flow path 250 for flowing a coolant is formed inside the base plate 200. When a process such as etching is performed in the semiconductor manufacturing apparatus, a coolant is supplied to the coolant flow path 250 from the outside, thereby cooling the base plate 200. Heat generated in the substrate W during the process is transferred to the coolant via the helium gas in the space SP1, the dielectric substrate 100, and the base plate 200, and is discharged to the outside together with the coolant.

[0025] An insulating film may be formed on the surface of the base plate 200. For example, an alumina film formed by thermal spraying can be used as the insulating film. By covering the surface of the base plate 200 with the insulating film, the dielectric strength of the base plate 200 can be increased.

[0026] The heater unit 300 generates heat when power is supplied from an external source, and heats the dielectric substrate 100. The heater unit 300 is provided with a plurality of heat generating parts (not shown), and the amount of heat generated by each heat generating part can be adjusted individually. By individually adjusting the amount of heat generated by each part, the in-plane temperature distribution of the substrate W during processing can be made closer to uniform.

[0027] The heater unit 300 is sandwiched between the dielectric substrate 100 and the base plate 200 and bonded to each of them. The heater unit 300 and the dielectric substrate 100 are bonded via a bonding layer 410, and the heater unit 300 and the base plate 200 are bonded via a bonding layer 420. The bonding layers 410 and 420 are layers formed by, for example, hardening a silicone adhesive. A plurality of particulate fillers (fillers) for increasing thermal conductivity are disposed inside each of the bonding layers. For example, particles mainly composed of alumina can be used as the filler.

[0028] 2 shows a schematic exploded view of the configuration of the heater unit 300. As shown in the figure, the heater unit 300 has a support plate 310 (310A), an insulating layer 320, a sub-heater layer 330, an insulating layer 340, a main heater layer 350, an insulating layer 360, a bypass layer 370, an insulating layer 380, a support plate 310 (310B), and a terminal 390. In this embodiment, the sub-heater layer 330, the main heater layer 350, and the bypass layer 370 are arranged in this order from the top, but the arrangement order of these may be different from that of this embodiment.

[0029] The support plate 310 is a substantially disk-shaped member, and is provided at each of the upper and lower ends of the heater unit 300 in FIG. 2. The support plate 310 provided at the upper end in FIG. 2 is also referred to as "support plate 310A" below. The support plate 310 provided at the lower end in FIG. 2 is also referred to as "support plate 310B" below. The support plate 310A is a portion bonded to the dielectric substrate 100 via a bonding layer 410, and the support plate 310B is a portion bonded to the base plate 200 via a bonding layer 420.

[0030] The pair of support plates 310A, 310B are members for reinforcing the entire heater unit 300 by sandwiching the entire sub-heater layer 330, the main heater layer 350, the bypass layer 370, etc. between them. In this embodiment, both the support plates 310A, 310B are made of metal, but they may be made of other materials (e.g., insulating materials). Note that, although a plurality of through holes are formed in each of the members constituting the heater unit 300, such as the support plate 310, for the purpose of passing lift pins through, etc., they are not shown in FIG. 2.

[0031] The insulating layer 320 is provided between the support plate 310A and the sub-heater layer 330, and serves to electrically insulate them from each other. The insulating layer 320 also serves to physically bond them together. In this embodiment, the insulating layer 320 is a polyimide film, but it may contain a component other than polyimide, or may be made of a material other than polyimide. When the support plate 310A is made of an insulating material, it is possible to eliminate the insulating layer 320.

[0032] The sub-heater layer 330 is a part that generates heat when power is supplied from the outside. In Fig. 2, the sub-heater layer 330 is depicted as a single disk, but in reality, the sub-heater layer 330 is divided into a plurality of regions, and each region is formed as a heating portion that is wired. This makes it possible to heat each region individually.

[0033] The insulating layer 340 is provided between the sub-heater layer 330 and the main heater layer 350, and serves to electrically insulate the two layers from each other. The insulating layer 340 also serves to physically bond the two layers together. In this embodiment, the insulating layer 340 is a polyimide film, but it may contain a component other than polyimide, or may be made of a material other than polyimide.

[0034] The main heater layer 350, like the sub-heater layer 330 described above, is a part that receives power from an external source and generates heat. In Fig. 2, the main heater layer 350 is depicted as a single disk, but in reality, the main heater layer 350 is divided into a plurality of regions, and each region is formed as a linearly routed heat generating portion. This makes it possible to heat each region individually. The number of divisions of the main heater layer 350 is smaller than that of the sub-heater layer 330.

[0035] The main heater layer 350 has a larger heat generation amount than the sub-heater layer 330 described above. The main heater layer 350 is intended to increase the temperature of the entire dielectric substrate 100 in a short period of time. The sub-heater layer 330 is intended to adjust the temperature of each part of the dielectric substrate 100 and make the in-plane temperature distribution of the substrate W closer to uniform. In this manner, in this embodiment, two heater layers are provided separately according to their respective roles. Alternatively, a configuration in which only one heater layer is provided may be used.

[0036] The insulating layer 360 is provided between the main heater layer 350 and the bypass layer 370, and serves to electrically insulate the two layers from each other. The insulating layer 360 also serves to physically bond the two layers together. In this embodiment, the insulating layer 360 is a polyimide film, but it may contain a component other than polyimide, or may be made of a material other than polyimide.

[0037] The bypass layer 370 is a layer for electrically connecting a terminal 390 (described later) to the sub-heater layer 330 or the main heater layer 350. In Fig. 2, the bypass layer 370 is illustrated as a single disk, but in reality, the bypass layer 370 is divided into a plurality of layers. By providing the bypass layer 370 in the middle of each electric path connecting the terminal 390 to the sub-heater layer 330 or the main heater layer 350, it becomes possible to adjust the position of the terminal 390, etc. Each of the divided bypass layers 370 has a portion welded to the sub-heater layer 330 or the main heater layer 350.

[0038] In addition, there may be a mode in which the terminal 390 and the sub-heater layer 330, and the terminal 390 and the main heater layer 350 are directly connected to each other. In this case, the bypass layer 370 is not necessary.

[0039] The insulating layer 380 is provided between the bypass layer 370 and the support plate 310B, and serves to electrically insulate the two. The insulating layer 380 also serves to physically bond the two. In this embodiment, the insulating layer 380 is a polyimide film, but it may contain a component other than polyimide, or may be made of a material other than polyimide. If the support plate 310B is made of an insulating material, it is possible to eliminate the insulating layer 380.

[0040] 2 are laminated, the entire assembly is pressurized and heated, and the entire assembly is bonded together via the insulating layer 320, which is a polyimide film, and the like.

[0041] The terminal 390 is a part that receives, from the outside, the power required to heat the sub-heater layer 330 and the like. The terminal 390 is made of metal. In this embodiment, the terminal 390 is formed as a long and thin rod-shaped plug, one end of which is connected to the bypass layer 370. The terminal 390 and the bypass layer 370 are connected by, for example, welding.

[0042] A plurality of terminals 390 are provided according to the number of bypass layers 370, but only two of them are shown in Fig. 2 and only one of them is shown in Fig. 1. When the bypass layer 370 is not provided on the base plate 200, the end of the terminal 390 is connected to either the sub-heater layer 330 or the main heater layer 350.

[0043] Each terminal 390 protrudes vertically from a surface of the heater unit 300 facing the base plate 200 (the lower side in FIGS. 1 and 2) toward the base plate 200. A through hole 230 is formed in the base plate 200 at each position corresponding to the terminal 390. The terminals 390 protruding from the heater unit 300 are accommodated inside the through hole 230.

[0044] The specific configuration of the terminal 390 and its vicinity will be described with reference to Fig. 3. Fig. 3 is an enlarged view of the configuration of the terminal 390 and its vicinity in Fig. 1. Note that in Fig. 3, the upper end of the terminal 390 is depicted as being connected to the lower end surface of the heater unit 300 (i.e., the support plate 310B in Fig. 2), but in reality, the upper end of the terminal 390 is connected to the bypass layer 370 inside the heater unit 300.

[0045] 3, the through hole 230 is formed so as to penetrate the base plate 200 from the surface 210 of the base plate 200 to the surface 220 on the opposite side. The central axis of the through hole 230 is perpendicular to the surface 210. A support member 500 is disposed inside the through hole 230. The support member 500 is a member for supporting the periphery of the terminal 390 inserted into the through hole 230, and is composed of a plurality of members. The support member 500 includes a first member 510, a second member 520, a third member 530, and a fourth member 540.

[0046] The first member 510 is a generally cylindrical member formed to extend in the vertical direction of FIG. 3. The first member 510 is made of metal and is conductive. The first member 510 is formed with a recess 511 extending downward from the upper end of FIG. 3. The recess 511 has a circular shape in top view, and its inner diameter is approximately equal to the outer diameter of the terminal 390. The central axis of the first member 510 and the central axis of the recess 511 are both aligned with the central axis of the through hole 230. As shown in FIG. 3, most of the terminal 390 is inserted into the recess 511, and is supported from the periphery by the first member 510.

[0047] An end face 512 of the first member 510 opposite to the heater unit 300 is exposed to the outside from the surface 220 side. As described above, the first member 510 is conductive and is electrically connected to the terminal 390. For this reason, for example, by contacting a contact probe (not shown) from the outside with the end face 512, it is possible to supply power from the outside to the heater unit 300. Note that the portion of the first member 510 near the end face 512 has a reduced diameter compared to the other portions, and is exposed to the outside through a fourth member 540 described below.

[0048] The second member 520 is a substantially cylindrical member formed so as to cover the first member 510 from the outside. The second member 520 is formed of an insulating material such as resin. The second member 520 is disposed between the inner peripheral surface of the through hole 230 and the outer peripheral surface of the first member 510. The second member 520 electrically insulates the base plate 200 and the first member 510.

[0049] The third member 530 is a substantially cylindrical member that covers the vicinity of the end portion of the first member 510 on the surface 210 side from the outside. The first member 510 is formed of an insulating material such as resin. In order to dispose such a third member 530, the portion of the through hole 230 on the surface 210 side is made larger in diameter than the other portions.

[0050] 3, neither the first member 510 nor the second member 520 extends to the height position of the surface 210 in the vertical direction of FIG. 3, and a space SP2 is formed on the upper side of each of them. On the other hand, the third member 530 extends to the height position of the surface 210 in the vertical direction of FIG.

[0051] 3, a protrusion 531 that protrudes inward is provided on a portion of the third member 530 that extends above the first member 510 in the vertical direction in FIG. The protrusion 531 is provided in an annular shape around the entire circumference on the inner circumferential surface of the third member 530. The protrusion 531 covers the end faces of the first member 510 and the second member 520.

[0052] An inclined surface 532 is formed around the entire circumference of the protrusion 531. The inclined surface 532 is inclined so as to move away from the heater unit 300 as it approaches the inner terminal 390. The inclined surface 532 defines a part of the space SP2 from the outer periphery. In other words, the inclined surface 532 is a part of the support member 500 that defines the space SP2.

[0053] The fourth member 540 is a generally cylindrical member that covers from the outside the portion of the first member 510 that is narrowed near the end of the surface 220, i.e., near the end surface 512. The outer diameter of the fourth member 540 is larger than that of the first member 510. The lower end of the second member 520 in FIG. 3 abuts against the upper end of the fourth member 540. The fourth member 540 is formed of an insulating material such as resin. In order to place such a fourth member 540, the portion of the through hole 230 on the surface 220 side is enlarged in diameter compared to other portions.

[0054] A female screw 231 is formed on the inner surface of the through hole 230 in a portion facing the fourth member 540. A male screw 541 is formed on the outer circumferential surface of the fourth member 540 and screws into the female screw 231. The entire support member 500 can be fixed to the base plate 200 by rotating the fourth member 540 around its central axis and fastening it.

[0055] The space SP2 described above is a space defined by the upper end surfaces of the first member 510 and the second member 520, the inclined surface 532 of the third member 530, and the like in FIG. Such a space SP2 can be said to be a space surrounding the periphery of the portion of the terminal 390 closest to the heater unit 300. As shown in FIG. 3, a part of the bonding layer 420 enters the space SP2 from the outer periphery side and abuts against the side surface of the terminal 390. In order to show the entire range of the space SP2, FIG. 5 shows an example in which the bonding layer 420 does not enter the space SP2 at all as a comparative example of this embodiment.

[0056] The reason for adopting the above-mentioned configuration will be described. When the substrate W is processed, the temperature of each part of the electrostatic chuck 10 increases. At this time, stress may be applied to the part of the terminal 390, particularly the part connected to the heater unit 300, due to differences in thermal expansion of each part. Depending on the magnitude of the stress, there is a risk that damage may occur in the connection part between the heater unit 300 and the terminal 390.

[0057] Therefore, in this embodiment (FIG. 3), as described above, a part of the bonding layer 420 enters the space SP2 and supports the terminal 390 together with the support member 500. In such a configuration, the base portion of the terminal 390 is supported and reinforced by the bonding layer 420 that enters the space SP2. This makes it possible to prevent defects in the connection portion between the heater unit 300 and the terminal 390, breakage of the path supplying power to the heater unit 300, etc. The entire space SP2 may be filled with the bonding layer 420.

[0058] To achieve such a configuration, for example, when manufacturing the electrostatic chuck 10, a predetermined amount of adhesive that will become the bonding layer 420 can be applied in advance to the portion that will become the space SP2 (e.g., on the inclined surface 532) or in the vicinity thereof.

[0059] The bonding layer 420 continuously surrounds the entire periphery of the terminal 390, thereby firmly supporting the terminal 390 from all directions. Instead of this embodiment, a part of the periphery of the terminal 390 may be not supported by the bonding layer 420.

[0060] In this embodiment, an inclined surface 532 is formed on a part of the support member 500. During bonding, the uncured adhesive that will later become the bonding layer 420 is widely supported from below by the inclined surface 532, so that most of it hardens while remaining on the inclined surface 532. This allows the portion that most needs reinforcement (the connection portion between the heater unit 300 and the terminal 390) to be supported and reinforced by the bonding layer 420.

[0061] Another advantage of forming the inclined surface 532 will be described. When assembling the electrostatic chuck 10, the support member 500 is attached to the base plate 200 in advance, and the terminal 390 is attached to the heater unit 300 in advance. Thereafter, the base plate 200 and the heater unit 300 are bonded to each other via an adhesive that becomes the bonding layer 420. At this time, it is necessary to move the heater unit 300 closer to the base plate 200 while aligning the positions so that the terminals 390 protruding from the heater unit 300 enter the recesses 511 of the support member 500 provided on the base plate. FIG. 4 shows a schematic diagram of the terminals 390 and the support member when such a process is being performed. The base plate 200 and the heater unit 300 are not shown.

[0062] 4, the lower end of terminal 390 slowly moves in the direction of the arrow and is inserted into recess 511. At this time, if there is a positional deviation and the central axis of terminal 390 and the central axis of recess 511 do not completely coincide with each other, there is a possibility that the insertion of terminal 390 will fail.

[0063] However, in this embodiment, the inclined surface 532 formed on the upper end of the support member 500 serves to guide the tip of the misaligned terminal 390 toward the central axis. This makes it possible to easily and reliably insert all of the multiple terminals 390 into the corresponding recesses 511.

[0064] As long as the same effects as those described above are obtained, the specific structure of the support member 500 may be different from that of the present embodiment. For example, the recess 511 may be formed as a through hole extending to the lower end of the first member 510, and the terminal 390 may be directly connected to an external connector through the through hole. In this case, the entire support member 500 may be integrally formed from an insulating material.

[0065] The heater unit 300 may be provided separately from the dielectric substrate 100 as in this embodiment, or may be integrated with the dielectric substrate 100. For example, a linear heat generating portion may be embedded inside the dielectric substrate 100, and a terminal 390 connected to the heat generating portion may be provided so as to protrude from the surface 120 side of the dielectric substrate 100. In this case, the dielectric substrate 100 corresponds to the "heater unit" and is joined to a base plate 200 having the same configuration as in this embodiment.

[0066] The present embodiment has been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. Any design modifications made by a person skilled in the art to these specific examples are also included within the scope of the present disclosure as long as they have the features of the present disclosure. The elements of each of the above-mentioned specific examples and their arrangements, conditions, shapes, etc. are not limited to those exemplified and can be changed as appropriate. The combination of each of the elements of each of the above-mentioned specific examples can be changed as appropriate as long as no technical contradiction occurs. [Explanation of symbols]

[0067] 10: Electrostatic chuck 200: Base plate 230:Through hole 300: Heater unit 390: Terminal 420: Bonding layer 500: Support member 532: Inclined surface SP2: Space

Claims

1. A heater unit that generates heat by receiving power from an external source; A base plate supporting the heater unit; a bonding layer that bonds the heater unit and the base plate, A terminal protruding from the heater unit toward the base plate is accommodated inside a through hole formed in the base plate, A support member is disposed inside the through hole to support the terminal from the periphery thereof, A space is formed around the portion of the terminal closest to the heater unit, a portion of the bonding layer extending into the space and supporting the terminal together with the support member;

2. 2. The electrostatic chuck according to claim 1, wherein the bonding layer supports the terminal by continuously surrounding the entire periphery of the terminal.

3. 2. The electrostatic chuck according to claim 1, wherein a portion of the support member that defines the space has an inclined surface that is inclined so as to move away from the heater unit as it approaches the inner terminal.

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