Electrostatic chuck

Abstract

Provided is an electrostatic chuck capable of preventing discharge between a power supply member and a base plate. The electrostatic chuck includes: a dielectric substrate; an internal electrode provided inside the dielectric substrate; a base plate in which a through hole is formed; a power supply member that is a member for supplying power to the internal electrode and that is inserted through the through hole; and an insulating member disposed between the inner surface of the through-hole and the power supply member. The insulating member includes: a cylindrical first insulating member; and a cylindrical second insulating member that covers a part of the first insulating member from the outer peripheral side. The electrostatic chuck is further provided with an annular member for preventing discharge from occurring along a path that passes between the first insulating member and the second insulating member from the power supply member and reaches the inner surface of the through-hole.

Description

TECHNICAL FIELD

[0001] The present application relates to an electrostatic chuck. BACKGROUND

[0002] For example, in a semiconductor manufacturing apparatus such as an etching apparatus, an electrostatic chuck is provided as a device that attracts and holds a substrate such as a silicon wafer that is a processing target. The electrostatic chuck has a dielectric substrate in which an attraction electrode is provided inside, and a base plate that supports the dielectric substrate, and has a structure in which these are joined to each other. If a voltage is applied to the attraction electrode, electrostatic force is generated, and a substrate placed on the dielectric substrate is attracted and held.

[0003] In addition, in the inside of the dielectric substrate, an RF electrode is sometimes provided. The RF electrode is used as one of a pair of opposed electrodes for generating plasma in a semiconductor manufacturing apparatus. A voltage is also applied to the RF electrode from the outside.

[0004] Hereinafter, such an electrode provided in the inside of the dielectric substrate as the attraction electrode or the RF electrode described above will be also collectively referred to as an "internal electrode". As described in Patent Document 1 below, a power supply member for supplying power to the internal electrode is provided in the electrostatic chuck. The power supply member is inserted through a through-hole of the base plate, and is electrically connected to the internal electrode of the dielectric substrate.

[0005] Patent Document Patent Document 1: Japanese Patent Application Laid-Open No. 2015-222748 SUMMARY

[0006] In order to prevent discharge from occurring between the power supply member and the base plate, it is preferable that the inner face of the through-hole of the base plate be covered by the insulating member as a whole from the upper end to the lower end thereof. The present inventors have studied a structure in which a first insulating member that is a cylindrical member and a second insulating member that is a cylindrical member covering a part of the first insulating member from the outer peripheral side are used as the insulating member described above. By making the structure in which the two cylindrical members overlap each other, even if there is a deviation in the dimensions of the members, the inner face of the through-hole of the base plate can be easily and surely covered as a whole.

[0007] However, when the structure described above is made, discharge can occur between the power supply member and the base plate on a path that passes through the gap between the first insulating member and the second insulating member.

[0008] The present application has been made in view of such a problem, and an object thereof is to provide an electrostatic chuck in which discharge between a power supply member and a base plate can be prevented.

[0009] To solve the above problems, the electrostatic chuck according to the present application includes: a dielectric substrate having a placement surface on which an object to be attracted is placed; an internal electrode provided inside the dielectric substrate; a base plate which is a metal member that supports the dielectric substrate and has a through-hole; a power supply member which is a member for supplying power to the internal electrode and is inserted through the through-hole; and an insulating member disposed between an inner surface of the through-hole and the power supply member. The insulating member includes: a first insulating member which is a cylindrical member; and a second insulating member which is a cylindrical member and covers a portion of the first insulating member from an outer peripheral side, and the inner surface of the through-hole is covered from an end portion on one side to an end portion on the other side by the first insulating member and the second insulating member. The electrostatic chuck further includes a discharge prevention member for preventing discharge along a path that reaches the inner surface of the through-hole from the power supply member via between the first insulating member and the second insulating member.

[0010] In the electrostatic chuck of the above structure, although the structure includes the first insulating member and the second insulating member as the insulating member, discharge along a path that passes between the two members can be surely prevented by the discharge prevention member.

[0011] According to the present application, an electrostatic chuck in which discharge between a power supply member and a base plate can be prevented can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is a cross-sectional view schematically showing a structure of an electrostatic chuck according to a first embodiment. Figure 2 is a view showing a part of the structure of the electrostatic chuck according to the first embodiment in an enlarged manner. Figure 3 is a view for explaining a discharge path in an electrostatic chuck according to a comparative example. Figure 4 is a view showing a part of the structure of the electrostatic chuck according to a second embodiment in an enlarged manner. Figure 5 is a view showing a part of the structure of the electrostatic chuck according to a third embodiment in an enlarged manner. Figure 6 is a view showing a part of the structure of the electrostatic chuck according to a fourth embodiment in an enlarged manner. Figure 7 is a view showing a part of the structure of the electrostatic chuck according to a fifth embodiment in an enlarged manner. SYMBOL DESCRIPTION 10 - electrostatic chuck; 100 - dielectric substrate; 110 - surface; 140 - internal electrode; 200 - base plate; 230 - through-hole; 400 - power supply member; 500 - insulating member; 510 - first insulating member; 520 - second insulating member; 530, 540 - ring-shaped member; 550 - insulating cover; W - substrate. Detailed Implementation

[0013] Hereinafter, this embodiment will be described with reference to the accompanying drawings. For ease of understanding, the same symbols will be used to label the same components as much as possible in each drawing, and repeated descriptions will be omitted.

[0014] The first embodiment will be described. The electrostatic chuck 10 of this embodiment, for example, is used inside a semiconductor manufacturing apparatus (not shown) such as an etching apparatus to attract and hold a substrate W to be processed by electrostatic force. The substrate W is, for example, a silicon wafer. The electrostatic chuck 10 can also be used in apparatuses other than semiconductor manufacturing apparatuses.

[0015] Figure 1 The diagram shows the structure of an electrostatic chuck 10 in a state of adsorbing and holding a substrate W, as a schematic cross-sectional view. The electrostatic chuck 10 includes a dielectric substrate 100 and a base plate 200.

[0016] The dielectric substrate 100 is a generally disk-shaped component made of sintered ceramic body. Although the dielectric substrate 100 may contain, for example, high-purity alumina (Al2O3), other materials may also be included. Considering the plasma resistance and other requirements of the dielectric substrate 100 in semiconductor manufacturing apparatuses, the purity and type of ceramic, additives, etc., in the dielectric substrate 100 can be appropriately set.

[0017] In the dielectric substrate 100, Figure 1 The upper side surface 110 of the substrate 100 serves as the "placement surface" for placing the substrate W. Additionally, in the dielectric substrate 100, Figure 1 The lower side surface 120 becomes the "joined surface" that is joined to the base plate 200 by the joining layer 300 described later. Hereinafter, the perspective when viewing the electrostatic chuck 10 from the side of surface 110 along a direction perpendicular to surface 110 will also be described as "top view".

[0018] An internal electrode 140 is disposed inside the dielectric substrate 100. The internal electrode 140 is a thin, flat layer formed of a metal material such as tungsten, and is arranged parallel to the surface 110. In addition to tungsten, molybdenum, platinum, palladium, etc., can also be used as the material for the internal electrode 130. The internal electrode 140 is also referred to as an "RF electrode" and is used as one of a pair of opposing electrodes for generating plasma in a semiconductor manufacturing apparatus. When the internal electrode 140 is powered by the power supply member 400 (described later), plasma is generated and attracted to the substrate W side. The structure of the power supply member 400 and its surrounding area will be described later.

[0019] Furthermore, in addition to the internal electrode 140, an adsorption electrode is also provided inside the dielectric substrate 100, but... Figure 1The diagram is omitted. The adsorption electrode is positioned closer to the surface 110 than the internal electrode 140. When an external voltage is applied to the adsorption electrode (not shown) via a power supply circuit (not shown), an electrostatic force is generated between the surface 110 and the substrate W, thereby adsorbing and holding the substrate W. The adsorption electrode can be provided as an electrode different from the internal electrode 140 as described above, but it can also be configured to use the internal electrode 140 as an adsorption electrode.

[0020] like Figure 1 As shown, a space SP is formed between the dielectric substrate 100 and the substrate W. During etching or other processes in the semiconductor manufacturing apparatus, an inert gas for temperature regulation is supplied to the space SP from the outside through a vent (not shown). By having the inert gas present between the dielectric substrate 100 and the substrate W, the thermal resistance between them is adjusted, thereby maintaining the temperature of the substrate W at an appropriate temperature. Furthermore, although helium is used in this embodiment as the inert gas supplied to the space SP for temperature regulation, a gas of a different type than helium can also be used.

[0021] A sealing ring 111 and a point 112 are provided on the placement surface, i.e., surface 110, and the aforementioned space SP is formed around these.

[0022] The sealing ring 111 is a wall that divides the space SP at the outermost periphery. The upper end of the sealing ring 111 becomes part of the surface 110 and abuts against the substrate W. Furthermore, multiple sealing rings 111 can be provided in a way that divides the space SP. With this structure, the pressure of helium gas in each space SP can be adjusted separately, and the surface temperature distribution of the substrate W during processing can be made more uniform.

[0023] Figure 1 In the diagram, the portion marked with the symbol "116" is the bottom surface of space SP. Hereinafter, this portion will also be referred to as "bottom surface 116". The sealing ring 111, together with point 112 (described below), is formed as a result of excavating a portion of surface 110 to the position of bottom surface 116. Bottom surface 116 is parallel to surface 110.

[0024] Point 112 is a circular protrusion extending from the bottom surface 116. Multiple points 112 are provided and are distributed approximately evenly on the placement surface of the dielectric substrate 100. The upper end of each point 112 becomes part of the surface 110 and abuts against the substrate W. By providing multiple such points 112, bending of the substrate W is suppressed.

[0025] The base plate 200 is a generally disk-shaped component that supports the dielectric substrate 100. The base plate 200 is formed of a metal material, such as aluminum. The base plate 200 is bonded to surface 120 of the dielectric substrate 100 by a bonding layer 300. In the base plate 200, Figure 1The upper side of the surface 210 in the above-described structure becomes a "bonding surface" that is bonded to the dielectric substrate 100.

[0026] The bonding layer 300 is a layer provided between the dielectric substrate 100 and the base plate 200 to bond the two. The bonding layer 300 is a layer formed by curing an adhesive material that is insulating. In the present embodiment, a silicone adhesive is used as the adhesive. However, the bonding layer 300 can also be a layer formed by curing another type of adhesive. In either case, it is preferable to use a material having a high thermal conductivity as the material of the bonding layer 300 so that the thermal resistance between the dielectric substrate 100 and the base plate 200 is small.

[0027] An insulating film can also be formed on the surface of the base plate 200. As the insulating film, for example, a film of aluminum oxide formed by sputtering can be used. By covering the surface of the base plate 200 with the insulating film, the dielectric withstand voltage of the base plate 200 can be improved.

[0028] Inside the base plate 200, a cooling medium flow path 250 for passing a cooling medium is formed. When etching or the like is performed in the semiconductor manufacturing apparatus, a cooling medium is supplied to the cooling medium flow path 250 from the outside, whereby the base plate 200 is cooled. In the process, heat generated on the substrate W is transferred to the cooling medium through the helium gas in the space SP, the dielectric substrate 100, and the base plate 200, and is discharged to the outside together with the cooling medium. In the base plate 200, the supply and discharge of the cooling medium to and from the cooling medium flow path 250 are performed through an unillustrated opening formed in the surface 220 opposite to the surface 210.

[0029] Reference will be made primarily to Figure 2 The power supply member 400 and the structure around it will be described. As described earlier, the power supply member 400 is a member for supplying power to the internal electrode 140. The power supply member 400 is a rod-shaped member, for example, composed of a material having electrical conductivity such as metal. In the power supply member 400, Figure 1 and Figure 2 the end portion on the upper side abuts against the internal electrode 140. The power supply member 400 protrudes more to the base plate 200 side than the surface 120 of the dielectric substrate 100. A through hole 230 is formed in the base plate 200, and the power supply member 400 is inserted inside the through hole 230.

[0030] As shown in Figure 2 , in the surface 120 of the dielectric substrate 100, a circular recess 130 that recedes to the internal electrode 140 side is formed. The recess 130 is a bottomed hole, and the internal electrode 140 is exposed on the bottom surface thereof. The power supply member 400 is inserted inside the recess 130, and one end of the power supply member 400 is pressed against the internal electrode 140 exposed as described above.

[0031] In the power supply member 400, a recess 402 is formed at an end portion opposite to the one end portion of the internal electrode 140 which is pressed. The recess 402 is a portion for receiving a power supply pin (not shown) for supplying power from the outside. When processing is performed in the semiconductor manufacturing apparatus, the power supply pin is inserted into the recess 402.

[0032] On the outer side surface 401 of the power supply member 400, an external thread 405 is formed in a portion near the end of the side on which the recess 402 is formed. The external thread 405 is screwed to an internal thread 525 to be described later which is formed on the insulating member 500. Thus, by rotating the power supply member 400 about its center axis, the power supply member 400 is moved along the center axis, and the one end portion thereof can be brought into a state of being pressed against the internal electrode 140.

[0033] At this time, in order to prevent the one end portion of the power supply member 400 from being excessively pressed against the internal electrode 140, an extension / contraction mechanism (not shown) can be provided on the power supply member 400. That is, the extension / contraction mechanism can be provided which, when the one end portion of the power supply member 400 is pressed against the internal electrode 140, the entire length of the power supply member 400 is shortened due to the reaction force from the internal electrode 140. At this time, if the power supply member 400 is configured to be restored to the original length by elasticity, the force applied from the power supply member 400 to the internal electrode 140 can be controlled to an appropriate size. Instead of such an extension / contraction mechanism, a member having elasticity and electrical conductivity can be provided between the tip end of the power supply member 400 and the internal electrode 140.

[0034] In addition, the insulating substrate 100 can be configured such that an electrode terminal electrically connected to the internal electrode 140 is provided on the surface 120, and the tip end of the power supply member 400 abuts against the electrode terminal. That is, the power supply member 400 can be configured not to directly abut against the internal electrode 140.

[0035] As described above, the base plate 200 is formed with a through-hole 230 through which the power supply member 400 is inserted. The through-hole 230 is formed to vertically pass through from the surface 210 to the surface 220 of the base plate 200. The cross-sectional shape of the through-hole 230 is circular at each height position from the surface 210 to the surface 220. However, the inner diameter of the through-hole 230 is not uniform as a whole, and is different at each height position.

[0036] The inner face of the through-hole 230 has a first inner face 231, a second inner face 232, and a third inner face 233. The first inner face 231 is the portion of the inner face of the through-hole 230 that is closest to the side of the face 210. The third inner face 233 is the portion of the inner face of the through-hole 230 that is closest to the side of the face 220. The second inner face 232 is the portion of the inner face of the through-hole 230 that is between the first inner face 231 and the third inner face 233. In each of the portions, the inner diameter of the through-hole 230 is substantially constant. The inner diameter of the second inner face 232 is greater than the inner diameter of the first inner face 231, and the inner diameter of the third inner face 233 is greater than the inner diameter of the second inner face 232.

[0037] Hereinafter, the face of the inner face of the through-hole 230 that is between the first inner face 231 and the second inner face 232 and that is parallel to the face 210 will also be referred to as "face 234". In addition, the face of the inner face of the through-hole 230 that is between the second inner face 232 and the third inner face 233 and that is parallel to the face 210 will also be referred to as "face 235".

[0038] The inner face of the through-hole 230 and the internal electrode 140 each have electrical conductivity, and are opposed to each other. Thus, when a voltage is applied to the power supply member 400, discharge can occur between the two. Therefore, the cylindrical insulating member 500 is disposed between the inner face of the through-hole 230 and the internal electrode 140, thereby preventing the occurrence of the discharge as described above. As the material of the insulating member 500, for example, a material having insulating properties such as alumina or resin can be used.

[0039] The entire insulating member 500 is not a single member, but includes mutually independent members, i.e., a first insulating member 510 and a second insulating member 520. Each of the first insulating member 510 and the second insulating member 520 has a substantially cylindrical shape. The central axis of the first insulating member 510 and the central axis of the second insulating member 520 each coincide with the central axis of the internal electrode 140.

[0040] The end portion of the first insulating member 510 on the side of the dielectric substrate 100 abuts against the face 120 of the dielectric substrate 100. The end portion 513 on the opposite side of the first insulating member 510 is located inside the base plate 200, i.e., between the face 210 and the face 220. Thus, the first insulating member 510 does not cover the entire inner face of the through-hole 230, but covers only the portion of the inner face that is closer to the side of the face 210.

[0041] The power supply member 400 extends to a position that is closer to the side of the face 220 than the end portion 513 of the first insulating member 510 (i.e., the lower side). Figure 2 The outer diameter of the first insulating member 510 is substantially the same as the inner diameter of the first inner face 231 of the through-hole 230. A slight gap is formed between the inner side face 511 of the first insulating member 510 and the outer side face 401 of the internal electrode 140.

[0042] exist Figure 2 The portion marked with the symbol "514" is the part near the upper end of the outer surface 512 of the first insulating member 510. Hereinafter, this portion will also be referred to as the "diameter-enlarged portion 514". The diameter-enlarged portion 514 has a conical shape in which the outer diameter gradually increases as it approaches the surface 120 of the dielectric substrate 100. The shape of the first inner surface 231 of this portion is also a conical shape corresponding to the diameter-enlarged portion 514.

[0043] The second insulating member 520 covers a portion of the first insulating member 510 from its outer peripheral side. The second insulating member 520... Figure 2 The lower end of the second insulating member 520 is located at the same height as surface 220. Figure 2 The upper end 522 is located inside the base plate 200, that is, between surface 210 and surface 220. Therefore, the second insulating member 520 does not cover the entire inner surface of the through hole 230, but only covers the portion of the inner surface closer to surface 220.

[0044] The end 522 of the second insulating member 520 is located closer to the surface 210 than the end 513 of the first insulating member 510 along the central axis of the through hole 230. In other words, the end 513 of the first insulating member 510 is located closer to the surface 220 than the end 522 of the second insulating member 520 along the central axis of the through hole 230.

[0045] In this embodiment, the first insulating member 510 covering the portion of the inner surface of the through hole 230 near the surface 210 and the second insulating member 520 covering the portion of the inner surface near the surface 220 overlap each other, thus covering the entire inner surface of the through hole 230. With this structure, even the dimensions of the individual members, such as the first insulating member 510 (especially...), are... Figure 2 There is a deviation in the vertical dimension of the through hole 230, and part of the inner surface of the through hole 230 is not covered by the insulating component 500.

[0046] Furthermore, the first insulating member 510 and the second insulating member 520 cover the inner surface of the through hole 230 as described above, but the term "cover" here means that the inner surface of the through hole 230 is not directly opposite to the power supply member 400. A gap may also be formed between the inner surface of the through hole 230 and the first insulating member 510 or the second insulating member 520 covering it.

[0047] The end portion 522 of the second insulating member 520 opposes the face 234 of the base plate 200, and a gap is formed between the end portion 522 and the face 234. In this gap, the annular member 530 is disposed. The annular member 530 is, for example, an electrically insulating member having elasticity such as rubber, and has a shape of a circular ring. The annular member 530 is in a state of being compressed by the end portion 522 and the face 234.

[0048] Figure 2 The portion indicated by the symbol "521" is a portion of the inner face of the second insulating member 520 that opposes the outer face 512 of the first insulating member 510. Hereinafter, this portion is also referred to as "inner face 521". A slight gap is formed between the inner face 521 and the outer face 512.

[0049] Figure 2 The portion indicated by the symbol "523" is a portion of the inner face of the second insulating member 520 that does not directly oppose the outer face 401 of the power supply member 400 via the first insulating member 510. Hereinafter, this portion is also referred to as "inner face 523". The inner diameter of the inner face 523 is smaller than the inner diameter of the inner face 521. A slight gap is formed between the inner face 523 and the outer face 401. An inner thread 525 is formed on a portion of the inner face 523. As described above, the inner thread 525 is screwed to the outer thread 405 formed on the outer face 401 of the power supply member 400.

[0050] Hereinafter, the face of the second insulating member 520 that is located between the inner face 521 and the inner face 523 and is parallel to the face 210 is also referred to as "face 524". The face 524 opposes the end portion 513 of the first insulating member 510. A gap is formed between the face 524 and the end portion 513.

[0051] On the end portion of the second insulating member 520 that is closest to the face 220, a portion that is expanded in diameter, i.e., a flange 526, is provided. The outer diameter of the flange 526 is substantially equal to the inner diameter of the third inner face 233. The flange 526 abuts on the face 235 from the lower side, thereby defining the position of the second insulating member 520 in the up-down direction. The second insulating member 520 is fixed to the base plate 200, for example, by press-fitting or adhesion. Figure 2

[0052] As described above, in the present embodiment, the entire inner face of the through-hole 230 from the end portion on one side to the end portion on the other side is covered by the first insulating member 510 and the second insulating member 520.

[0053] However, in such a structure, discharge can occur between the power supply member and the base plate on a path that passes through the gap between the first insulating member 510 and the second insulating member 520. Specifically, for example, discharge can occur along the path indicated by the arrow A in FIG. 6. Figure 3 ​Along the path indicated by the arrow AR, discharge from the power supply member 400 to the inner face of the through-hole 230 can occur.

[0054] Therefore, in the present embodiment, the annular member 530 is interposed between the tip end (end portion 522) of the second insulating member 520 and the face 234 of the base plate 200, so as to prevent the occurrence of the above-described discharge. The annular member 530 is an elastic member, and is in a state of being compressed by being interposed between the end portion 522 and the face 234. Therefore, the annular member 530 blocks the gap between the first insulating member 510 and the second insulating member 520 (specifically, the gap between the inner side face 521 and the outer side face 512), and blocks the path along which discharge can occur. In order to surely prevent discharge, it is preferable that the annular member 530 abut on the outer side face 512 of the first insulating member 510 over the entire circumference. It is also possible to make a portion of the annular member 530 that is deformed by being compressed enter the gap between the inner side face 521 and the outer side face 512.

[0055] The annular member 530 is a member for preventing discharge along the path from the power supply member 400, through the gap between the first insulating member 510 and the second insulating member 520, to the inner face of the through-hole 230, and corresponds to the "discharge prevention member" in the present embodiment.

[0056] As the material of the annular member 530, any material can be used as long as it is an electrically insulating material having elasticity. For example, a material such as silicone rubber or a fluorine-based polymer can be used.

[0057] The structure of the power supply member 400 or the insulating member 500 described above can be applied not only to a power supply circuit connected to the internal electrode 140 (that is, the RF electrode), but also to a power supply circuit connected to an adsorption electrode that is not shown.

[0058] In the present embodiment, the first insulating member 510 covers the portion of the inner face of the through-hole 230 that is closer to the face 210, and the second insulating member 520 covers the portion of the inner face of the through-hole 230 that is closer to the face 220. The positional relationship between the first insulating member 510 and the second insulating member 520 can also be reversed from the above. That is, it is also possible to make the second insulating member 520 cover the portion of the inner face of the through-hole 230 that is closer to the face 210, and the first insulating member 510 cover the portion of the inner face of the through-hole 230 that is closer to the face 220.

[0059] The second embodiment will be described. Hereinafter, mainly the portions different from the first embodiment will be described, and the description of the portions common to the first embodiment will be appropriately omitted.

[0060] Figure 4 is the same as Figure 2The same view depicts the structure of the power supply member 400 and its vicinity according to the present embodiment. In the present embodiment, a ring member 540 is provided instead of the ring member 530. The ring member 540 is an electrically insulating material having elasticity. The ring member 540 is a member that is fixed to the top end (end portion 522) of the second insulating member 520 in advance at a timing before the second insulating member 520 is installed to the base plate 200. Since the ring member 540 is installed over the entire surface of the end portion 522, it has a shape of a circular ring. As the material of the ring member 540, for example, a material such as silicone rubber or fluorine-based polymer can be used. The ring member 540 can be fixed to the end portion 522 by adhesion or the like, and for example, can also be formed by applying rubber coating to the end portion 522.

[0061] When the second insulating member 520 is inserted into the inside of the through-hole 230, the ring member 540 is in a state of being compressed while being sandwiched between the end portion 522 and the surface 234 of the base plate 200. At this time, the deformed ring member 540 is in a state of abutting against the outer side surface 512 of the first insulating member 510 over the entire circumference. As a result, like the ring member 530 of the first embodiment, the ring member 540 is in a state of blocking the gap between the inner side surface 521 and the outer side surface 512, and blocking the path in which discharge is likely to occur. The ring member 540 corresponds to the "discharge prevention member" in the present embodiment. Even in such a configuration, the same effects as those explained in the first embodiment can be exerted.

[0062] In the present embodiment, the ring member 540 is fixed to the end portion 522 of the second insulating member 520 in advance, and thus an advantage that the disassembly and reassembly are easy can also be obtained.

[0063] A third embodiment will be described. Hereinafter, mainly the portions different from the first embodiment will be described, and the portions common to the first embodiment will be appropriately omitted.

[0064] Figure 5 is the same as Figure 2This diagram depicts the structure of the power supply member 400 and its surrounding portion according to the same perspective. In this embodiment, the annular member 530 is disposed in the gap between the end 513 of the first insulating member 510 and the surface 524 of the second insulating member 520, and is compressed between them. Similar to the first embodiment, the annular member 530 blocks the gap between the first insulating member 510 and the second insulating member 520 (specifically, the gap between the inner surface 521 and the outer surface 512), blocking the path where discharge may occur. To reliably prevent discharge, it is preferable that the annular member 530 abuts against the outer surface 512 of the first insulating member 510 across its entire circumference. It is also possible for the compressed and deformed annular member 530 to enter the gap between the inner surface 521 and the outer surface 512. Even in such a configuration, the same effect as described in the first embodiment can be achieved.

[0065] The fourth embodiment will be described. Hereinafter, the parts that differ from the first embodiment will be mainly described, and the parts that are the same as those in the first embodiment will be omitted as appropriate.

[0066] Figure 6 Therefore with Figure 2 This diagram depicts the structure of the power supply component 400 and its surrounding area according to the same perspective. In this embodiment, it becomes the second embodiment ( Figure 4 The annular member 540 is pre-fixed to the end 513 of the first insulating member 510, as described in the previous section, instead of being fixed to the end 522 of the second insulating member 520.

[0067] In this embodiment, the annular member 540 is a member that is pre-fixed to the top end (end 513) of the first insulating member 510 before the first insulating member 510 is disposed inside the through hole 230. Since the annular member 540 is installed across the entire span of the end 513, its shape is annular. Materials such as silicone rubber or fluoropolymers can be used as the material for the annular member 540. The annular member 540 can be fixed to the end 513 by bonding or, for example, by applying a rubber coating to the end 513.

[0068] When the first insulating member 510 and the second insulating member 520 are inserted into the inside of the through-hole 230, the annular member 540 is in a state of being compressed between the end portion 513 of the first insulating member 510 and the face 524 of the second insulating member 520. At this time, the annular member 540 that has been deformed is in a state of abutting on the outer side face 512 of the first insulating member 510 over the entire circumference. As a result, as with the annular member 530 of the first embodiment, the annular member 540 is in a state of plugging the gap between the inner side face 521 and the outer side face 512, blocking the path in which discharge is likely to occur. The annular member 540 corresponds to the "discharge preventing member" in the present embodiment. Even in such a configuration, the same effects as those explained in the first embodiment can be exerted.

[0069] In the present embodiment, the annular member 540 is fixed to the end portion 513 of the first insulating member 510 in advance, and thus the advantage that the reassembly after disassembly is easy can also be obtained.

[0070] The fifth embodiment will be described. Hereinafter, mainly the portions different from the first embodiment will be described, and the description of the portions common to the first embodiment will be appropriately omitted.

[0071] Figure 7 is a view that depicts the structure of the power supply member 400 and the portion near the power supply member 400 from the same perspective as Figure 2 In the present embodiment, a structure in which an insulating cover 550 is provided instead of the annular member 530 is adopted. The insulating cover 550 is a sheet-like member that is provided to cover a portion of the outer side face 401 of the power supply member 400 from the outside over the entire circumference. The material of the insulating cover 550 has electrical insulating properties. It is preferable that the insulating cover 550 be provided to cover at least the portion of the outer side face 401 with respect to the portion between the end portion 513 and the inner side face 523. That is, it is preferable that the insulating cover 550 be provided to cover at least the portion that is likely to be the starting point of discharge as shown in Figure 3

[0072] The insulating cover 550 can be a rubber coating that covers the outer side face 401, or can be a heat shrink tube. In addition, it can be a covering film formed of a material such as polyvinyl chloride, silicone rubber, fluorinated polymer, or the like. By providing the insulating cover 550, discharge occurrence through between the first insulating member 510 and the second insulating member 520 is prevented. The insulating cover 550 corresponds to the "discharge preventing member" in the present embodiment. Even in such a configuration, the same effects as those explained in the first embodiment can be exerted.

[0073] ​The present application is not limited to the above-described embodiments. The technical scope of the present application also encompasses the technical scope of the following embodiments. The above-described embodiments are described with reference to specific examples. However, the present application is not limited to these specific examples. As long as the features of the present application are possessed, the technical scope of the present application also encompasses technologies that are appropriately designed by those skilled in the art. The elements, configurations, conditions, shapes, and the like possessed by the above-described embodiments are not limited to the illustrated examples, but can be appropriately changed. As long as there is no technical contradiction, the elements possessed by the above-described embodiments can be appropriately combined.

Claims

1. An electrostatic chuck, characterized in that, Features: a dielectric substrate with a surface for placing the adsorbed object; Internal electrodes are disposed inside the dielectric substrate. The base plate is a metal component that supports the dielectric substrate and has through holes. A power supply component is a component used to supply power to the internal electrodes and is inserted into the through hole; An insulating component is disposed between the inner surface of the through hole and the power supply component. The insulating member includes: a cylindrical first insulating member; And a cylindrical second insulating member, which covers a portion of the first insulating member from the outer peripheral side. The first insulating member and the second insulating member cover the inner surface of the through hole from one end to the other end. It also includes a discharge prevention component for preventing discharge along the path from the power supply component through the first insulating component and the second insulating component to the inner surface of the through hole.

2. The electrostatic chuck according to claim 1, characterized in that, The discharge prevention component is an electrically insulating component that covers the outer surface of the power supply component.

3. The electrostatic chuck according to claim 1, characterized in that, The discharge prevention member is an electrically insulating member that is provided in a manner that blocks the gap between the first insulating member and the second insulating member.

4. The electrostatic chuck according to claim 3, characterized in that, The discharge prevention component is an elastic component.

5. The electrostatic chuck according to claim 4, characterized in that, The discharge prevention component is compressed and sandwiched between the top of the second insulating component and the base plate.

6. The electrostatic chuck according to claim 5, characterized in that, The discharge prevention component is pre-fixed to the top of the second insulating component.

7. The electrostatic chuck according to claim 4, characterized in that, The discharge prevention member is compressed and sandwiched between the top of the first insulating member and the second insulating member.

8. The electrostatic chuck according to claim 7, characterized in that, The discharge prevention component is pre-fixed to the top of the first insulating component.

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