Electrostatic chuck

Abstract

To provide an electrostatic chuck capable of sufficiently suppressing generation of discharge.SOLUTION: The electrostatic chuck 10 includes a dielectric substrate 100 in which a first through hole 140 is formed, a base plate 200 which is a metal member supporting the dielectric substrate 100 and in which a second through hole 240 is formed at a position corresponding to the first through hole 140, a bonding layer 300 which bonds the dielectric substrate 100 and the base plate 200, and a ventilation member 400 which is a member having ventilation properties and is supported inside the second through hole 240 in a state where a part thereof protrudes from a surface 210 of the base plate 200 toward the dielectric substrate 100. A supply flow path 250 for supplying a gas into the second through-hole 240 is formed in the base plate 200.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] For example, semiconductor manufacturing equipment such as etching equipment is provided with an electrostatic chuck 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 that supports 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.

[0003] An inert gas such as helium is supplied to the space between the dielectric substrate and the substrate for the purpose of adjusting the temperature of the substrate during processing, etc. For example, as described in Patent Document 1 below, the inert gas is supplied to the space through gas holes formed in each of the base plate and the dielectric substrate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-203426 Summary of the Invention [Problem to be solved by the invention]

[0005] A ventilation member made of an insulating material having air permeability may be placed inside the gas hole formed in the base plate. By placing the ventilation member, the occurrence of discharge in the path through the gas hole is suppressed.

[0006] To sufficiently suppress the occurrence of discharge, it is desirable to have the ventilation member protrude from the surface of the base plate toward the dielectric substrate and to minimize the gap between the ventilation member and the dielectric substrate. One possible method for achieving this is, for example, to insert the ventilation member into the gas hole of the base plate from the dielectric substrate side, and then join the dielectric substrate and the base plate in a state in which a portion of the ventilation member protrudes toward the dielectric substrate by a predetermined distance. It is preferable to set the amount of protrusion of the ventilation member large enough so that the gap between the ventilation member and the dielectric substrate is zero after joining.

[0007] However, if the protrusion amount of the ventilation member becomes too large due to dimensional variations, there is a risk that the ventilation member will come into contact with the dielectric substrate during bonding and damage the dielectric substrate. Therefore, it was necessary to keep the protrusion amount of the ventilation member small to some extent, taking into account dimensional variations. In other words, it was necessary to ensure a large gap between the ventilation member and the dielectric substrate. As a result, it was difficult to sufficiently suppress discharge.

[0008] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an electrostatic chuck that can sufficiently suppress the occurrence of discharge. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention provides an electrostatic chuck comprising: a dielectric substrate having a mounting surface on which an object to be attracted is placed and having a first through hole formed therein; a base plate which is a metal member supporting the dielectric substrate and has a second through hole formed at a position corresponding to the first through hole; a bonding layer which bonds the dielectric substrate to the base plate; and a ventilation member which is an air-permeable member supported inside the second through hole with a portion of the ventilation member protruding from the surface of the base plate toward the dielectric substrate. The base plate has a supply flow path formed therein for supplying a gas into the second through hole.

[0010] In the electrostatic chuck having the above configuration, a first through-hole is formed in the dielectric substrate and a second through-hole is formed in the base plate as gas holes for supplying an inert gas, and a ventilation member is supported inside the second through-hole with a part of the ventilation member protruding toward the dielectric substrate.

[0011] The second through hole is formed as a "through hole" that penetrates the base plate. Therefore, for example, after the dielectric substrate and the base plate are joined, it is possible to insert a ventilation member into the second through hole from the opening of the base plate on the side opposite the dielectric substrate. Because there is no need to design a large gap between the ventilation member and the dielectric substrate in consideration of the possibility of damage during joining, the gap can easily be reduced to close to zero. As a result, the occurrence of discharge can be sufficiently suppressed. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide an electrostatic chuck that can sufficiently suppress the occurrence of discharge. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a cross-sectional view schematically showing the configuration of an electrostatic chuck according to a first embodiment. [Figure 2] 2 is an enlarged view showing in detail a portion of the configuration of the electrostatic chuck of FIG. 1. FIG. [Figure 3] 3 is a further enlarged view showing in detail a portion of the configuration of the electrostatic chuck of FIG. 2. FIG. [Figure 4] FIG. 10 is a cross-sectional view schematically showing the configuration of an electrostatic chuck according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, the present embodiment will be described with reference to the accompanying drawings. To facilitate understanding of the description, the same components in the drawings will be denoted by the same reference numerals as much as possible, and duplicated descriptions will be omitted.

[0015] A first embodiment will be described. An 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 object to be attracted, that is, the substrate W, is, for example, a silicon wafer. The electrostatic chuck 10 may also be used in apparatuses other than semiconductor manufacturing apparatuses.

[0016] 1 is a schematic cross-sectional view showing the configuration of an electrostatic chuck 10 in a state where the electrostatic chuck 10 attracts and holds a substrate W. The electrostatic chuck 10 includes a dielectric substrate 100 and a base plate 200.

[0017] 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 also 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.

[0018] 1 of the dielectric substrate 100 is a "mounting surface" on which the substrate W is placed. Also, a lower surface 120 of the dielectric substrate 100 in FIG. 1 is a "bonded surface" that is bonded to the base plate 200 via a bonding layer 300. 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 also be referred to as a "top view."

[0019] An attraction electrode (not shown) is embedded inside the dielectric substrate 100. The attraction electrode is a thin, flat layer made of a metal material such as tungsten, and is arranged parallel to the surface 110. In addition to tungsten, other materials that can be used for the attraction electrode include molybdenum, platinum, and palladium. When a voltage is applied to the attraction electrode from the outside via a power supply path (not shown), an electrostatic force is generated between the surface 110 and the substrate W, thereby attracting and holding the substrate W. Only one attraction electrode may be provided as a so-called "monopolar" electrode, or two may be provided as so-called "bipolar" electrodes.

[0020] 1, a space SP 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 to the space SP from the outside via a first through-hole 140 (described later) or the like. By providing helium gas 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. Note that the temperature adjustment gas supplied to the space SP may be a type of gas other than helium.

[0021] A seal ring 111 and dots 112 are provided on a surface 110 that is a mounting surface, and the space SP is formed around these.

[0022] The seal ring 111 is a wall that divides the space SP at the outermost position. The seal ring 111 is an annular protrusion formed on the surface 110. The upper end of the seal ring 111 forms part of the surface 110 and abuts against the substrate W. Note that multiple seal rings 111 may be provided to divide the space SP. With this configuration, it is possible to individually adjust the pressure of the helium gas in each space SP and make the surface temperature distribution of the substrate W during processing more uniform.

[0023] 1, the portion marked with the reference numeral "116" is the bottom surface of the space SP. 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 by digging down a portion of the surface 110 to the position of the bottom surface 116.

[0024] The dots 112 are circular protrusions that protrude 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 tip of each dot 112 forms part of the surface 110 and comes into contact with the substrate W. By providing a plurality of such dots 112, bending of the substrate W is suppressed.

[0025] A first through hole 140 is formed in the dielectric substrate 100. The first through hole 140 is a circular through hole formed to extend in a direction perpendicular to the surface 110, which is the mounting surface. The end of the first through hole 140 on the surface 110 side is connected to the space SP. The end of the first through hole 140 on the opposite side to the end mentioned above is open at the surface 120. The first through hole 140 is part of a flow path for supplying helium gas toward the space SP. A plurality of first through holes 140 are formed in the dielectric substrate 100, but only one of them is shown in FIG. 1 . A porous member or the like for preventing discharge may be disposed inside the first through hole 140.

[0026] The base plate 200 is a substantially disk-shaped member 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 the surface 120 of the dielectric substrate 100 via a bonding layer 300. The surface 210 of the base plate 200, which is on the upper side in FIG. 1, is the "bonded surface" that is bonded to the dielectric substrate 100.

[0027] The bonding layer 300 is a layer provided between the dielectric substrate 100 and the base plate 200, and bonds them together. The bonding layer 300 is formed by curing an adhesive made of an insulating material. In this embodiment, a silicone adhesive is used as the adhesive. However, the bonding layer 300 may be formed by curing another type of adhesive. In either case, it is preferable to use a material with as high a thermal conductivity as possible as the material for the bonding layer 300 so as to reduce the thermal resistance between the dielectric substrate 100 and the base plate 200.

[0028] 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 an insulating film, the dielectric strength of the base plate 200 can be increased.

[0029] A coolant flow path 260 for passing a coolant is formed inside the base plate 200. When a process such as etching is performed in the semiconductor manufacturing equipment, a coolant is supplied to the coolant flow path 260 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 SP, the dielectric substrate 100, and the base plate 200, and is discharged to the outside together with the coolant. The coolant is supplied to and discharged from the coolant flow path 260 through an opening (not shown) formed in a surface 220 of the base plate 200 opposite to the surface 210.

[0030] Second through holes 240 are formed in the base plate 200. The second through holes 240 are holes formed to extend in a direction perpendicular to the surface 110, which is the mounting surface, and extend from the surface 210 to the surface 220. The second through holes 240 are formed at positions that overlap the first through holes 140 in a top view (i.e., positions corresponding to the first through holes 140) and are communicated with the first through holes 140. The second through holes 240, together with the first through holes 140 in the dielectric substrate 100, form part of a flow path for supplying helium gas toward the space SP on the mounting surface side. The end of each second through hole 240 on the surface 220 side is blocked by a sealing member 600, which will be described later. Helium gas is supplied to each second through hole 240 not from the end of each second through hole 240 on the surface 220 side, but from a supply flow path 250, which will be described next.

[0031] A supply flow path 250 is formed inside the base plate 200. The supply flow path 250 is routed parallel to the surface 210 and is connected to each of the second through holes 240 from the lateral side. The supply flow path 250 is a flow path for supplying helium gas to the inside of each of the second through holes 240. The supply of helium gas from the outside to the supply flow path 250 is performed, for example, through an opening (not shown) formed in the surface 220. By forming the supply flow path 250 inside the base plate 200, the number of openings for receiving the supply of helium gas from the outside can be reduced.

[0032] As described above, the base plate 200 has a relatively complex internal structure, with the refrigerant flow path 260, the supply flow path 250, the second through-hole 240, and the like formed therein. To facilitate the formation of the refrigerant flow path 260 and the like, the base plate 200 of this embodiment is formed by joining multiple members. Specifically, the base plate 200 is formed by joining together three members, namely, a first member 201, a second member 202, and a third member 203, into an integrated unit. The members are joined by welding, but may also be joined by methods such as brazing or fastening. The number of members constituting the base plate 200 may be four or more, or may be two.

[0033] The first member 201, the second member 202, and the third member 203 are arranged in this order along a direction perpendicular to the surface 110, which is the mounting surface. The first member 201 is the part of the members constituting the base plate 200 that is closest to the dielectric substrate 100. The surface 210 mentioned above is a part of the first member 201. The third member 203 is the part of the members constituting the base plate 200 that is on the opposite side from the dielectric substrate 100. The surface 220 mentioned above is a part of the third member 203. The second member 202 is a member that is between the first member 201 and the third member 203.

[0034] A joint boundary B1 between the first member 201 and the second member 202 is parallel to the surface 110 and the surface 210. A joint boundary B2 between the second member 202 and the third member 203 is also parallel to the surface 110 and the surface 210.

[0035] The entire supply flow path 250 is formed in the first member 201. The supply flow path 250 is a groove that is formed in advance along the surface of the first member 201 that will become the joining boundary B1 before the respective members are joined. In this way, by forming the groove in advance on the surface of the first member 201 and then joining the second member 202 so as to cover this surface, the supply flow path 250 that follows the groove can be easily formed inside the base plate 200. Note that the groove that will become the supply flow path 250 may be formed not on the surface of the first member 201 but on the surface of the second member 202 that will become the joining boundary B1.

[0036] The entire coolant flow path 260 is formed in the second member 202. The coolant flow path 260 is a groove that is formed in advance along the surface of the second member 202 that will become the joining boundary B2 before the respective members are joined. In this way, by forming the groove in advance on the surface of the second member 202 and then joining the third member 203 so as to cover this surface, the coolant flow path 260 that follows the groove can be easily formed inside the base plate 200. Note that the groove that will become the coolant flow path 260 may also be formed on the surface of the second member 202 that will become the joining boundary B1.

[0037] 2 shows the configuration of the second through hole 240 and its vicinity in detail. As shown in the figure, the second through hole 240 is formed to penetrate vertically from the surface 210 to the surface 220 of the base plate 200. The cross-sectional shape of the second through hole 240 at each height position from the surface 210 to the surface 220 is circular. However, the inner diameter of the second through hole 240 is not constant throughout, but varies at each height position. The second through hole 240 has a first portion 241, a second portion 242, and a third portion 243.

[0038] The first portion 241 is the portion of the second through hole 240 closest to the surface 210. The third portion 243 is the portion of the second through hole 240 closest to the surface 220. The second portion 242 is the portion of the second through hole 240 between the first portion 241 and the third portion 243. The inner diameter of the second through hole 240 is generally constant in each portion. The inner diameter in the second portion 242 is larger than the inner diameter in the first portion 241, and the inner diameter in the third portion 243 is even larger than the inner diameter in the second portion 242.

[0039] The first portion 241 extends from the surface 210 to a height position between the surface 210 and the bonding boundary B1. The second portion 242 extends from a height position between the surface 210 and the bonding boundary B1 to a height position between the bonding boundary B2 and the surface 220. The third portion 243 extends from a height position between the bonding boundary B2 and the surface 220 to the surface 220.

[0040] A ventilation member 400 is disposed inside the first portion 241 of the second through hole 240. The ventilation member 400 is a member made of, for example, alumina, and a part of it (a porous portion 410 described below) is breathable. By disposing such a ventilation member 400 inside the second through hole 240, the flow of helium gas in the second through hole 240 is ensured, while the occurrence of discharge in the path through the second through hole 240 is suppressed.

[0041] The ventilation member 400 is a substantially cylindrical member, and is disposed inside the first portion 241 with its central axis coinciding with the central axis of the first portion 241. The outer diameter of the ventilation member 400 is approximately equal to the inner diameter of the first portion 241. The ventilation member 400 is supported from below in FIGS. 1 and 2 by a support member 500, which will be described later.

[0042] The ventilation member 400 has a porous portion 410 and a dense portion 420, which are integrated together.

[0043] The porous portion 410 is a portion formed from porous ceramic having air permeability. Helium gas supplied to the space SP passes through the porous portion 410 of the ventilation member 400. The porosity of the porous portion 410 is set appropriately depending on the balance between the air permeability required for gas supply to the space SP and the necessary dielectric strength voltage. The porous portion 410 is cylindrical, and its central axis coincides with the central axis of the entire ventilation member 400.

[0044] The dense portion 420 is a portion formed from dense ceramic that does not have gas permeability. In other words, the dense portion 420 is a portion of the ventilation member 400 through which helium gas does not pass. The ceramic material (alumina in this embodiment) forming the dense portion 420 is the same as the ceramic material forming the porous portion 410. Alternatively, the two portions may be formed from different materials.

[0045] The dense portion 420 has a cylindrical shape, and its central axis coincides with the central axis of the entire ventilation member 400. The porous portion 410 described above is housed inside the dense portion 420. The dimension of the dense portion 420 in the up-down direction in FIG. 2 is the same as the dimension of the porous portion 410 in the same direction. The porous portion 410 and the dense portion 420 may be formed by joining separate separable members together, or they may be formed as a single unit by sintering from the beginning. Alternatively, the ventilation member 400 may not be provided with a dense portion 420, and the entire ventilation member 400 may be the porous portion 410.

[0046] The ventilation member 400 is supported inside the second through hole 240 with a part of it protruding from the surface 210 of the base plate toward the dielectric substrate 100 (upward in FIG. 2). The amount of protrusion of the ventilation member 400 is approximately the same as the thickness of the bonding layer 300. Therefore, the size of the gap between the end of the ventilation member 400 on the dielectric substrate 100 side and the surface 120 of the dielectric substrate 100 is approximately zero.

[0047] 3, a sealing member 450 is disposed around the protruding portion of the ventilation member 400 as described above, surrounding the protruding portion. The sealing member 450 is an annular member made of, for example, resin. Inside the sealing member 450, i.e., in the portion between the ventilation member 400 and the dielectric substrate 100, the bonding layer 300 is removed to form an opening. The ventilation member 400 protrudes from the inside of this opening as described above.

[0048] Returning to Figure 2, the explanation will continue. A support member 500 is disposed inside the second through hole 240. The support member 500 is a member that supports the end of the ventilation member 400 opposite the dielectric substrate 100, and determines the position of the second through hole 240 in the up-down direction in Figure 2. The support member 500 has a support portion 510 and a main body portion 520, which are formed as a whole as an integrated member. The support member 500 is formed from an insulating material such as resin.

[0049] The support portion 510 is a portion of the support member 500 that faces the dielectric substrate 100. The support portion 510 is substantially cylindrical, and its outer diameter is approximately equal to the inner diameter of the first portion 241 of the second through hole 240. The support portion 510 enters the inside of the first portion 241 from the lower side in FIG. 2. The upper end of the support portion 510 abuts against the lower end of the ventilation member 400, and supports the ventilation member 400 from below.

[0050] The main body portion 520 is the portion of the support member 500 excluding the support portion 510. The main body portion 520 is substantially cylindrical, and its outer diameter is approximately equal to the inner diameter of the second portion 242 of the second through hole 240. The central axis of the main body portion 520 coincides with the central axis of the support portion 510. The entire main body portion 520 is located inside the second portion 242.

[0051] A male screw 524 is formed on the outer peripheral surface of the main body 520 on the surface 220 side. Furthermore, a female screw 245 is formed on the inner peripheral surface of the second portion 242. The male screw 524 and the female screw 245 are threadedly engaged with each other. Therefore, by rotating the support member 500 around its central axis, the support member 500 can be moved along the central axis, and the amount of protrusion of the ventilation member 400 from the surface 210 can be changed.

[0052] A through hole 521 is formed in the support member 500. The through hole 521 is a circular through hole that passes through the entire support member 500 in the vertical direction in Figure 2. The central axis of the through hole 521 coincides with the central axis of the support member 500.

[0053] A groove 522 is formed in the outer peripheral surface of the main body portion 520 of the support member 500. The groove 522 is an annular groove formed in the outer peripheral surface of the main body portion 520 so as to extend in the circumferential direction. The height position at which the groove 522 is formed is approximately the same as the height position of the supply flow path 250. Therefore, the internal space of the supply flow path 250 and the internal space of the groove 522 are connected to each other.

[0054] The support member 500 is further formed with through holes 523. The through holes 523 are circular through holes formed to extend linearly from the bottom surface of the groove 522 toward the inside of the through hole 521. In this embodiment, a total of four through holes 523 are formed at the same height position. Each of the through holes 523 extends linearly toward the central axis of the support member 500. When viewed from above, the central axes of a pair of adjacent through holes 523 intersect with each other at an angle of 90 degrees.

[0055] With the above-described configuration, helium gas supplied from supply flow path 250 to second through hole 240 first flows into groove 522, and then passes through through hole 523, through hole 521, ventilation member 400, and first through hole 140 in that order before being supplied to space SP.

[0056] The grooves 522, the through holes 523, and the through holes 521 formed in the support member 500 function as a "guide flow path" for guiding the helium gas supplied from the supply flow path 250 to the ventilation member 400. The support member 500 of the present embodiment has both the function of supporting the ventilation member 400 from below and the function of guiding the helium gas supplied from the supply flow path 250 to the ventilation member 400.

[0057] In addition to the ventilation member 400 and the support member 500, a sealing member 600 is also arranged inside the second through hole 240. The sealing member 600 closes the end of the second through hole 240 opposite the dielectric substrate 100. The sealing member 600 prevents helium gas from leaking from this end.

[0058] The sealing member 600 has a screw portion 610 and a sealing portion 620, which are formed as a single unit. The screw portion 610 is the upper portion of the sealing member 600 in FIG. 2 and is disposed inside the second portion 242 of the second through hole 240. The screw portion 610 is substantially cylindrical, and its central axis coincides with the central axis of the second portion 242. A male screw 611 is formed on the outer peripheral surface of the screw portion 610, and this male screw 611 is threadedly engaged with a female screw 245 formed on the inner peripheral surface of the second portion 242. Therefore, by rotating the sealing member 600 around its central axis, the sealing member 600 can be moved along the central axis.

[0059] 2 below the screw portion 610. The sealing portion 620 has a generally circular disk shape. The outer diameter of the sealing portion 620 is larger than the outer diameter of the screw portion 610 and is generally equal to the inner diameter of the third portion 243 of the second through hole 240.

[0060] 2, a circular groove 621 is formed in the surface of sealing portion 620 on the upper side. A sealing member 630 is disposed inside groove 621. Sealing member 630 is a circular member made of, for example, resin, and is sandwiched and compressed between sealing portion 620 and base plate 200. Sealing portion 620 and sealing member 630 prevent helium gas inside second through-hole 240 from leaking to the outside.

[0061] The sealing member 600 is preferably made of a metal material such as stainless steel, which can reduce the amount of helium gas that leaks through the sealing member 600 to a negligible level.

[0062] In the electrostatic chuck 10 according to this embodiment, a portion of the ventilation member 400 protrudes from the surface 210, thereby reducing the gap between the ventilation member 400 and the dielectric substrate 100, thereby suppressing the occurrence of discharge along a path through the gas holes (such as the first through holes 140). To achieve this, a portion of the ventilation member 400 may be preliminarily protruded from the surface 210 prior to bonding using the bonding layer 300. For example, a countersunk hole may be formed in the surface 210 in advance, and the ventilation member 400 may be inserted into the countersunk hole, thereby causing a portion of the ventilation member 400 to protrude from the surface 210 prior to bonding. Then, by bonding the dielectric substrate 100 and the base plate 200 together, a configuration similar to that of this embodiment can be achieved.

[0063] However, in the above configuration, if the protrusion amount becomes too large due to dimensional variations in the ventilation member 400, there is a risk that the tip of the ventilation member 400 will hit the surface 120 of the dielectric substrate 100 during bonding, damaging the dielectric substrate 100. For this reason, the protrusion amount of the ventilation member 400 must be kept small to a certain extent, taking into account dimensional variations. In other words, in the above configuration, it is necessary to ensure a large gap between the ventilation member 400 and the dielectric substrate 100. In such a configuration, it is difficult to sufficiently suppress discharge.

[0064] Therefore, in the electrostatic chuck 10 according to this embodiment, the gas holes on the base plate 200 side where the ventilation member 400 is disposed are formed as through-holes that linearly penetrate the entire base plate 200, i.e., second through-holes 240. The inner diameter of the second through-hole 240 is generally the same as or larger than the outer diameter of the ventilation member 400 throughout the entire portion. In other words, the second through-hole 240 is formed in a shape that allows the ventilation member 400 to pass through its entirety in a direction perpendicular to the mounting surface (surface 110). Therefore, the ventilation member 400 can be inserted into the second through-hole 240 from the surface 220 side, not from the surface 210 side, and moved to the position shown in FIG. 2 .

[0065] When manufacturing the electrostatic chuck 10, for example, the dielectric substrate 100 and the base plate 200 may be bonded together before the ventilation member 400 or the like is placed inside the second through hole 240. Thereafter, a portion of the bonding layer 300 (the portion inside the sealing member 450 in FIG. 3 ) may be removed, and the ventilation member 400 or the like may be inserted into the second through hole 240 from the surface 220 side. Specifically, the sealing member 450, the ventilation member 400, and the support member 500 may be inserted into the second through hole 240 in this order. Thereafter, the second through hole 240 may be sealed with the sealing member 600.

[0066] The amount of protrusion of the ventilation member 400 from the surface 210 can be adjusted by adjusting the position of the support member 500. At this point, the bonding between the dielectric substrate 100 and the base plate 200 has already been completed. Therefore, the tip of the ventilation member 400 can be brought as close as possible to the dielectric substrate 100 without having to consider the possibility of damage during bonding. In other words, the amount of protrusion of the ventilation member 400 can be adjusted so that the size of the gap between the dielectric substrate 100 and the ventilation member 400 becomes approximately zero. As a result, the occurrence of discharge in paths through the first through holes 140 and the like can be sufficiently suppressed.

[0067] The ventilation member 400 may be supported on the inner surface of the second through hole 240 by, for example, adhesive bonding, without using the support member 500. However, if the support member 500 is used as in this embodiment, the protrusion amount of the ventilation member 400 can be easily adjusted. In this embodiment, a male screw 524 is further formed on the outer peripheral surface of the ventilation member 400, making the above-mentioned adjustment even easier. Furthermore, a guide flow path consisting of the groove 522, the through hole 523, and the through hole 521 is formed inside the ventilation member 400. Therefore, the flow of helium gas toward the ventilation member 400 is not obstructed by the support member 500.

[0068] The second embodiment will be described below. The following mainly describes the differences from the first embodiment, and the description of the commonalities with the first embodiment will be omitted as appropriate.

[0069] Fig. 4 schematically illustrates the configuration of the electrostatic chuck 10 according to this embodiment from the same perspective as Fig. 1. A support table 700 shown in Fig. 4 is part of a semiconductor manufacturing apparatus and is a table for supporting the entire electrostatic chuck 10 from below. The electrostatic chuck 10 is fixed to the upper surface of the support table 700 by fastening or the like.

[0070] In this embodiment, no sealing member 600 is provided inside the second through hole 240. In this embodiment, the end of the second through hole 240 opposite the dielectric substrate 100 is blocked by a support base 700. In this embodiment, the second through hole 240 does not have a third portion 243. In this embodiment, the portion of the second through hole 240 that is formed in the third member 203 is the second portion 242 in its entirety.

[0071] An annular groove 710 is formed on the upper surface of the support base 700. The groove 710 is formed so as to surround the entire second through hole 240 from the outside when viewed from above. A seal member 720 is disposed inside the groove 710. The seal member 720 is an annular member made of, for example, resin, and is sandwiched and compressed between the support base 700 and the base plate 200. The support base 700 and the seal member 720 prevent the helium gas inside the second through hole 240 from leaking to the outside. This aspect also achieves the same effects as those described in the first embodiment.

[0072] The present embodiment has been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. Design modifications to these specific examples made by a person skilled in the art as appropriate are also included within the scope of the present disclosure as long as they comprise the features of the present disclosure. The elements of the above-described specific examples, as well as their arrangement, conditions, shape, etc., are not limited to those exemplified and can be modified as appropriate. The elements of the above-described specific examples can be combined in various ways as appropriate, as long as no technical contradictions arise. [Explanation of symbols]

[0073] 10: Electrostatic chuck 100: Dielectric substrate 110: Face 140: First through hole 200: Base plate 210: Face 240: Second through hole 245: Female screw 250: Supply channel 300: Bonding layer 400: Ventilation material 500: Support member 521:Through hole 522: Groove 523:Through hole 524: Male screw 600: Sealing member W: Substrate

Claims

1. a dielectric substrate having a mounting surface on which an object to be attracted is placed and in which a first through hole is formed; a base plate, which is a metal member supporting the dielectric substrate, and has a second through hole formed at a position corresponding to the first through hole; a bonding layer that bonds the dielectric substrate and the base plate together; a ventilation member that is supported inside the second through hole with a portion of the ventilation member protruding from the surface of the base plate toward the dielectric substrate, The electrostatic chuck according to claim 1, wherein the base plate has a supply passage formed therein for supplying a gas into the second through hole.

2. The second through hole is entirely 2. The electrostatic chuck according to claim 1, wherein the electrostatic chuck is formed in a shape that allows a ventilation member to pass through in a direction perpendicular to the mounting surface.

3. a support member is disposed inside the second through hole, 2. The electrostatic chuck according to claim 1, wherein an end of said ventilation member opposite said dielectric substrate is supported by said support member.

4. 4. The electrostatic chuck according to claim 3, wherein the support member is formed with a guide passage for guiding the gas supplied from the supply passage to the ventilation member.

5. A male screw is formed on the outer circumferential surface of the support member, A female screw is formed on the inner circumferential surface of the second through hole, 4. The electrostatic chuck according to claim 3, wherein the male screw and the female screw are threadedly engaged with each other.

6. 4. The electrostatic chuck according to claim 3, wherein said support member is made of an insulating material.

7. The electrostatic chuck according to claim 1 , further comprising a sealing member closing an end of the second through hole opposite to the dielectric substrate.

8. 8. The electrostatic chuck according to claim 7, wherein the sealing member is made of a metal material.

Images