Electrostatic chuck

Abstract

Provided is an electrostatic chuck that can suppress deviation in the in-plane temperature distribution of a substrate during processing. An electrostatic chuck (10) includes: a dielectric substrate (100); an RF electrode (140) disposed inside the dielectric substrate (100); a base plate (200) formed of metal and joined to the dielectric substrate (100); and a connection member (400) that electrically connects between the RF electrode (140) and the base plate (200). Inside the base plate (200), a cooling medium flow path (250) through which a cooling medium passes is formed, and the connection member (400) is disposed at a position at which at least a portion thereof overlaps the cooling medium flow path (250) when viewed from above.

Description

Technical Field

[0001] This invention relates to an electrostatic chuck. Background Technology

[0002] For example, in semiconductor manufacturing equipment such as etching apparatus, electrostatic chucks are provided as devices for adsorbing and holding substrates such as silicon wafers that are to be processed. An electrostatic chuck comprises: a dielectric substrate on which adsorption electrodes are provided; and a base plate supporting the dielectric substrate, having a structure in which these are joined together. When a voltage is applied to the adsorption electrodes, an electrostatic force is generated, adsorbing and holding the substrate placed on the dielectric substrate.

[0003] As described in Patent Document 1 below, an RF electrode is sometimes built into the dielectric substrate. This RF electrode is one of a pair of opposing electrodes used to generate plasma in a semiconductor manufacturing apparatus. In this case, an electrical connection is made between the RF electrode and the base plate by means of a conductive connecting member. Thus, during the processing of the substrate, the potential of the RF electrode is maintained at the potential of the base plate (e.g., ground potential).

[0004] Patent documents Patent Document 1: International Publication No. 2022 / 255118 Summary of the Invention

[0005] To electrically connect the aforementioned connecting member to the RF electrode, a recess can be formed on the substrate side of the dielectric substrate, exposing the RF electrode on its bottom surface. The connecting member is then housed inside the recess. Alternatively, to electrically connect the RF electrode to the substrate using this connecting member, a recess can also be formed on the substrate side of the substrate, and the connecting member can be housed inside this recess. The connecting member is sandwiched between the dielectric substrate and the substrate.

[0006] However, when a substrate is processed in a semiconductor manufacturing apparatus, Joule heating is generated on the interconnect components as an AC voltage is applied to the RF electrodes. Depending on the heat generated by the interconnect components, the portion of the dielectric substrate located directly above the interconnect components may experience localized overheating due to the heat from the interconnect components.

[0007] Thus, the connecting member may become a heating source for the dielectric substrate or the adsorbed material. Consequently, depending on the position of the connecting member, the deviation in the in-plane temperature distribution of the substrate during processing may be excessive.

[0008] The present invention was made in view of such problems, and its object is to provide an electrostatic chuck that can suppress deviations in the in-plane temperature distribution of a substrate during processing.

[0009] To address the aforementioned issues, the electrostatic chuck of the present invention comprises: a dielectric substrate having a mounting surface for placing an object to be adsorbed; an RF electrode disposed inside the dielectric substrate; a base plate formed of metal and bonded to the dielectric substrate; and a connecting member for electrically connecting the RF electrode and the base plate. A cooling medium flow path is formed inside the base plate for the passage of a cooling medium. When viewed from a direction perpendicular to the mounting surface, the connecting member is positioned such that at least a portion of it overlaps with the cooling medium flow path.

[0010] In the electrostatic chuck with the above structure, the connecting member, which could potentially become a heat source, is positioned at a location overlapping the flow path of the cooling medium. In such a structure, the heat generated on the connecting member is efficiently recovered by the cooling medium, thus suppressing deviations in the in-plane temperature distribution of the substrate during processing.

[0011] According to the present invention, an electrostatic chuck is provided that can suppress deviations in the in-plane temperature distribution of a substrate during processing. Attached Figure Description

[0012] Figure 1 This is a cross-sectional view showing the structure of the electrostatic chuck according to the first embodiment. Figure 2 It means Figure 1 A diagram showing the structure of the dielectric substrate mounting surface of an electrostatic chuck. Figure 3 This is a diagram showing the structure of the cooling medium flow path formed inside the base plate. Figure 4 This is a cross-sectional view showing in detail the structure of the connecting member and the surrounding portion of the electrostatic chuck according to the first embodiment. Figure 5 It is a three-dimensional diagram showing the structure of the connecting components. Figure 6 It is a diagram used to illustrate the positional relationship between the cooling medium flow path and connecting components, etc. Figure 7 This is a cross-sectional view showing in detail the structure of the connecting member and the surrounding portion of the electrostatic chuck according to the second embodiment. Symbol Explanation 10-Electrostatic chuck; 100-Dielectric substrate; 110-Surface; 140-RF electrode; 200-Base plate; 250-Cooling medium flow path; 400-Connecting component; 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 is used, for example, 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 attracted object, i.e., 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 structure of the electrostatic chuck 10, which is in a state of adsorbing and holding the substrate W, is shown 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 for the dielectric substrate 100 in semiconductor manufacturing apparatuses, the purity, type, and additives of the ceramic in the dielectric substrate 100 can be appropriately set.

[0017] In dielectric substrate 100, Figure 1 The upper side surface 110 of the dielectric substrate 100 becomes the "mounting surface" of 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. Hereinafter, the view when viewing the electrostatic chuck 10 from the side of surface 110 along the direction perpendicular to surface 110 will also be described as "top view".

[0018] An adsorption electrode 130 is embedded inside the dielectric substrate 100. The adsorption electrode 130 is a thin, flat layer formed of a metal material such as tungsten, and is arranged parallel to the surface 110. Besides tungsten, molybdenum, platinum, palladium, etc., can also be used as the material for the adsorption electrode 130. If a voltage is applied to the adsorption electrode 130 from the outside 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. Various known structures can be used as the structure of the power supply circuit described above. The adsorption electrode 130 can be provided as a single "monopolar" electrode as in this embodiment, or as two "bipolar" electrodes.

[0019] Inside the dielectric substrate 100, in addition to the aforementioned adsorption electrode 130, an RF electrode 140 is also embedded. The RF electrode 140 is provided as one of a pair of opposing electrodes used to generate plasma in a semiconductor manufacturing apparatus. The other opposing electrode is positioned closer to the upper side than the electrostatic chuck 10 in the semiconductor manufacturing apparatus. If a high-frequency alternating voltage is applied between these opposing electrodes, plasma is generated on the upper side of the substrate W for use in processes such as film deposition or etching of the substrate W.

[0020] Similar to the adsorption electrode 130, the RF electrode 140 is also a thin, flat layer formed of a metallic material such as tungsten. Besides tungsten, other materials for the RF electrode 140 include molybdenum, platinum, and palladium. The RF electrode 140 is positioned closer to surface 120 than the adsorption electrode 130. Like the adsorption electrode 130, the RF electrode 140 is also configured parallel to surface 110. When viewed from above, the RF electrode 140 is a generally circular single electrode. When viewed from above, the center of the RF electrode 140 coincides with the center of the dielectric substrate 100.

[0021] The electrostatic chuck 10 is provided with a connecting member 400. The connecting member 400 is a member used to electrically connect the RF electrode 140 and the base plate 200 (described later). Through the connecting member 400, during the processing of the substrate W, the potential of the RF electrode 140 is the same as the potential of the base plate 200. Figure 1 In the diagram, the connecting member 400 is drawn as a simple straight line in a stylized manner. The specific shape of the connecting member 400 will be explained later.

[0022] like Figure 1 As shown, a space SP is formed between the dielectric substrate 100 and the substrate W. During etching and other processes in a semiconductor manufacturing apparatus, the space SP is formed by... Figure 1 The pore 114 is not shown in the diagram (see reference). Figure 2 Helium gas for temperature regulation is supplied from the outside to the space SP. By having helium 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, the gas supplied to the space SP for temperature regulation can also be a gas of a different type than helium.

[0023] Figure 2 This diagram shows the dielectric substrate 100 from a top-down view. As shown in the diagram, a sealing ring 150 and a point 113 are provided on the mounting surface, i.e., surface 110, and the aforementioned space SP is formed around these. Furthermore, Figure 1 The diagram for point 113 is omitted.

[0024] The sealing ring 150 is an annular protrusion provided as a wall dividing the space SP. Multiple sealing rings 150 are provided, arranged in a roughly concentric circle when viewed from above. The top surface of each sealing ring 150 ( Figure 1 The upper surface of the substrate SP becomes part of the surface 110 and abuts against the substrate W. In this embodiment, a total of two sealing rings 150 are provided, thereby dividing the space SP into two. By adopting such a structure, the pressure of helium gas in each space SP can be adjusted individually, and the surface temperature distribution of the substrate W during processing can be made more uniform.

[0025] Hereinafter, the sealing ring 150 disposed on the outer side will also be referred to as "first sealing ring 151". In addition, the sealing ring 150 disposed on the inner side will also be referred to as "second sealing ring 152".

[0026] The first sealing ring 151 is a sealing ring 150 disposed at the outermost peripheral end of the mounting surface, i.e., surface 110. The second sealing ring 152 is a sealing ring 150 disposed inside the first sealing ring 151, and there are no other sealing rings 150 between them. Alternatively, other sealing rings 150 may be provided inside the second sealing ring 152. Furthermore, a configuration may be adopted in which only one first sealing ring 151 is provided, and no other sealing rings 150 are present.

[0027] Figure 1 and Figure 2 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 150, together with point 113 described below, is formed as a result of excavating a portion of surface 110 up to the position of bottom surface 116.

[0028] Point 113 is a circular protrusion projecting from the bottom surface 116. (Example) Figure 2 As shown, a plurality of points 113 are provided and dispersedly arranged on the mounting surface of the dielectric substrate 100. The upper end surface of each point 113 becomes part of the surface 110 and abuts against the substrate W. By providing a plurality of such points 113, bending of the substrate W is suppressed.

[0029] Hereinafter, among the plurality of points 113, a group of points 113 arranged in a ring along the first sealing ring 151 from the innermost position will also be referred to as "point 113A". In addition, among the plurality of points 113, a group of points 113 arranged in a ring along the second sealing ring 152 from the innermost position will also be referred to as "point 113B".

[0030] Although the dots 113 can be evenly distributed across the entire mounting surface of the dielectric substrate 100, they can also be densely distributed in a portion. In this embodiment, when viewed from above, the density of dots 113 in the outer peripheral portion is higher than that in the central portion. Specifically, the density of dots 113A and 113B is higher than that of other dots 113. By arranging multiple dots 113 in this way, the outer peripheral portion of the substrate W, which is prone to relatively high temperatures, can be cooled efficiently, and deviations in the in-plane temperature distribution of the substrate W can be suppressed.

[0031] like Figure 2 As shown, a plurality of pores 114 are formed on the dielectric substrate 100. Figure 1 The illustration of the vent 114 is omitted. The vent 114 is a hole for supplying helium gas to the space SP, and is a circular through hole formed vertically from the surface 120 to the surface 110. Helium gas supplied from the outside is supplied to the space SP through the respective vent 114 after passing through a gas flow path (not shown) formed inside the base plate 200.

[0032] In this embodiment, each of the two spaces SP is connected with a plurality of pores 114. Inside the pores 114, a porous material formed of, for example, alumina can be disposed. By employing such a structure, gas flow within the pores 114 is ensured while insulation breakdown along the path through the pores 114 is suppressed.

[0033] On the bottom surface 116 of the space SP, grooves can also be formed to increase the in-plane diffusion rate of helium.

[0034] Back Figure 1 Continuing with the description, the base plate 200 is a generally disk-shaped component that supports the dielectric substrate 100. The base plate 200 is formed, for example, of a metallic 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 1 The upper side surface 210 becomes the "bonded surface" that is bonded to the dielectric substrate 100.

[0035] The bonding layer 300 is a layer disposed between the dielectric substrate 100 and the base plate 200, bonding the two together. The bonding layer 300 is a layer 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 can also be a layer formed by curing other types of adhesives. In any case, it is preferable to use a material with the highest possible thermal conductivity as the material for the bonding layer 300, so as to minimize the thermal resistance between the dielectric substrate 100 and the base plate 200.

[0036] An insulating film may also be formed on the surface of the base plate 200. For example, an aluminum oxide 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 insulation withstand voltage of the base plate 200 can be improved.

[0037] Inside the base plate 200, a cooling medium flow path 250 is formed for the passage of a cooling medium. During processes such as etching in a semiconductor manufacturing apparatus, a cooling medium is supplied from the outside to the cooling medium flow path 250, thereby cooling the base plate 200. During processing, heat generated on the substrate W is transferred to the cooling medium via helium gas in the space SP, the dielectric substrate 100, and the base plate 200, and is discharged to the outside along with the cooling medium. In the base plate 200, openings 251 and 252 (…) are formed on the surface 220 opposite to the surface 210. Figure 1 Not shown in the image, please refer to the diagram. Figure 3 ), to supply and discharge the cooling medium into the cooling medium flow path 250.

[0038] Figure 3 In the diagram, the structure of the cooling medium flow path 250 formed inside the base plate 200 is schematically drawn from a top-down perspective. As previously described, openings 251 and 252 are provided on the surface 220 of the base plate 200. The cooling medium flow path 250 connects the openings 251 and 252, forming a path that appears to pass through the approximate entire base plate 200 when viewed from above. Most of the cooling medium flow path 250 is formed to extend along an arc concentric with the circular base plate 200.

[0039] When viewed from above, openings 251 and 252 are both circular, extending perpendicularly to the surface 220 from the surface 220 into the cooling medium flow path 250. The internal spaces of openings 251 and 252 can also be considered as part of the cooling medium flow path 250. In this embodiment, cooling medium is supplied to opening 251 from the outside. The cooling medium flowing through the cooling medium flow path 250 and used for cooling the substrate W is discharged to the outside from opening 252.

[0040] Reference Figure 4 The specific structure of the connecting member 400 and its surrounding area will be described, for example. Figure 4As shown, a first recess 160 is formed on the surface 120 of the dielectric substrate 100 on the base plate 200 side. The first recess 160 is a portion of the surface 120 that recedes concavely toward the surface 110 side to allow for the placement of the connecting member 400. In this embodiment, the first recess 160 is formed to a depth that exposes the RF electrode 140. Therefore, the internal electrode, i.e., the RF electrode 140, is exposed on the bottom surface 162 of the first recess 160. When viewed from above, the first recess 160 is circular in shape, with a generally cylindrical space formed inside it.

[0041] A second recess 260 is formed on the surface 210 of the base plate 200 on the dielectric substrate 100 side. The second recess 260 is formed on the surface 210 and overlaps with the first recess 160 when viewed from above. The second recess 260 is a portion of the surface 210 that is recessed towards the surface 220 to allow for the placement of the connecting member 400. The metal portion of the base plate 200 is exposed entirely inside the second recess 260. When viewed from above, the second recess 260 is circular in shape, with a generally cylindrical space formed inside. The central axis of the second recess 260 coincides with the central axis of the first recess 160. However, the diameter of the inner peripheral surface 261 of the second recess 260 is smaller than the diameter of the inner peripheral surface 161 of the first recess 160.

[0042] On the bonding layer 300, a circular opening is formed in the portion between the first recess 160 and the second recess 260. The first recess 160 and the second recess 260 are connected by this opening, and these together form a space.

[0043] Figure 4 The component marked with the symbol "310" is configured to prevent uncured adhesive from entering the inner side of the first recess 160 and the second recess 260. Hereinafter, this component will also be referred to as "blocking portion 310". The blocking portion 310 is a ring-shaped component configured to surround the first recess 160 from the outside across its entire circumference when viewed from above. Although the inner diameter of the blocking portion 310 is the same as the inner diameter of the first recess 160, it can also be a different size. For example, cured silicone adhesive may be used as the blocking portion 310.

[0044] The connecting member 400 is a generally cylindrical member formed of fibrous metal components and is housed inside the first recess 160 and the second recess 260. That is, a portion of the connecting member 400 is housed in the first recess 160, and the other portion of the connecting member 400 is housed in the second recess 260.

[0045] The connecting member 400 abuts against the RF electrode 140 exposed on the bottom surface 162 of the first recess 160. Additionally, the connecting member 400 also abuts against the metal portion of the base plate 200 exposed on the bottom surface 262 of the second recess 260. Through this configuration of the connecting member 400, an electrical connection is established between the RF electrode 140 and the metal portion of the base plate 200.

[0046] like Figure 5 As shown, the connecting member 400 has a cylindrical body portion 410 and a plurality of protrusions 420, and is integrally formed from a fibrous metal component. When viewed from above, the connecting member 400 is circular in shape. Hereinafter, the diameter of this circle, i.e., the diameter of the body portion 410, will also be referred to as "diameter D1".

[0047] The protrusion 420 is a generally cylindrical protrusion that extends further from the surface of the body portion 410 toward the dielectric substrate 100 side. In this embodiment, a total of four protrusions 420 are formed, but the number of protrusions 420 may also be different.

[0048] The connecting member 400, composed of fibrous metal components, has a degree of permeability that allows fluids such as air or adhesives to enter its interior. In other words, the fibrous metal components are not completely dense; rather, gaps exist between the fibers. By employing this structure, the connecting member 400 becomes an elastic body, including the protrusion 420, whose components are easily deformable under external forces.

[0049] When not subjected to external force, the vertical dimension of the connecting member 400 (the extension direction of the protrusion 420) is greater than that of the connecting member 400. Figure 5 The dimensions in the same direction under the same state. That is, the connecting member 400 is housed inside the first recess 160 and the second recess 260 and sandwiched between the RF electrode 140 and the base plate 200 in a compressed state along the direction from the dielectric substrate 100 toward the base plate 200. The top tip of each protrusion 420 is pressed against the bottom surface 162 of the first recess 160 (that is, the RF electrode 140), and thus undergoes elastic deformation in a flattened manner.

[0050] The connecting member 400 is pressed against the RF electrode 140 and the base plate 200 respectively by its own restoring force. Therefore, even if the parts of the electrostatic chuck 10 undergo thermal expansion or contraction during the processing of the substrate W, the RF electrode 140 and the base plate 200 will always maintain an electrical connection.

[0051] The shape of the connecting member 400 can also be similar to... Figure 5 Different shapes. For example, the connecting member 400 can also be made into a roughly cylindrical shape and into a shape without the protrusion 420.

[0052] Although the number of connecting members 400 can be one, this embodiment provides multiple connecting members 400. Figure 2 The diagram shows the positions of the plurality of connecting members 400 provided in the electrostatic chuck 10. Furthermore, although the connecting members 400 cannot be visually observed from the side of surface 110 in the actual structure, they are shown for ease of explanation. Figure 2 Each of the connecting components 400 is drawn so that it can be visually observed from the side 110 through the dielectric substrate 100.

[0053] like Figure 2 As shown, when viewed from above, the multiple connecting members 400 are all disposed in the area between the first sealing ring 151 and the second sealing ring 152. When viewed from above, the diameter D1 of the connecting member 400 is smaller than the distance D2 between the first sealing ring 151 and the second sealing ring 152.

[0054] The multiple connecting members 400 are configured to be arranged in a ring along the second sealing ring 152. Figure 2 The dotted line DL shown is an imaginary line extending parallel to the second sealing ring 152. When viewed from above, the dotted line DL is circular, and its center coincides with the center of the dielectric substrate 100 and the base plate 200. When viewed from above, all connecting members 400 are configured such that the center of each connecting member 400 is located on the dotted line DL.

[0055] In this embodiment, each connecting member 400 is positioned so that, when viewed from above, it does not overlap with either the first sealing ring 151 or the second sealing ring 152. In other words, when viewing any one connecting member 400 from above, it does not overlap with any of the sealing rings 150. This applies to all connecting members 400 provided in the electrostatic chuck 10.

[0056] like Figure 2 As shown, in the portion between the first sealing ring 151 and the second sealing ring 152, in addition to the connecting member 400, a plurality of vents 114 are also provided. The vents 114 in this portion are all arranged such that, when viewed from above, their center position is located on the dashed line DL. That is, in this embodiment, the connecting member 400 and the vents 114 are arranged in a ring and a row when viewed from above.

[0057] However, when the substrate W is processed in a semiconductor manufacturing apparatus, Joule heat is generated on the connection member 400 as an AC voltage is applied to the RF electrode 140. Depending on the heat generated by the connection member 400, the portion of the dielectric substrate 100 located directly above the connection member 400 may experience localized overheating due to the heat from the connection member 400.

[0058] Thus, the connecting member 400 may become a heat source for the dielectric substrate 100 or the substrate W. Therefore, depending on the position of the connecting member 400, the deviation in the in-plane temperature distribution of the substrate W during processing may be too large.

[0059] Therefore, in the electrostatic chuck 10 according to this embodiment, each connecting member 400 is positioned to overlap with the cooling medium flow path 250 when viewed from above. In this structure, the heat generated on the connecting member 400 is efficiently recovered by the cooling medium, thus suppressing deviations in the in-plane temperature distribution of the substrate W during processing.

[0060] Figure 6 In the figure, a portion of the cooling medium flow path 250 is drawn from a top-down perspective, and the connecting member 400 and the vent 114 are schematically drawn above it. As shown in the figure, the connecting member 400 is positioned where its entirety overlaps with the cooling medium flow path 250 when viewed from above. That is, when focusing on any one of the connecting members 400, its entirety overlaps with the cooling medium flow path 250 when viewed from above. When viewed from above, the diameter D1 of the connecting member 400 is smaller than the width D3 of the cooling medium flow path.

[0061] When considering any connecting member 400, the portion of that connecting member 400 that overlaps with the cooling medium flow path 250 when viewed from above can be the entire connecting member 400, as in this embodiment, or it can be only a part of the connecting member 400. That is, it can also be in a form where the connecting member 400 partially overlaps with the cooling medium flow path 250. However, in order to efficiently recover the heat generated on the connecting member 400, it is preferable that the portion of the connecting member 400 that overlaps with the cooling medium flow path 250 is as large as possible. Preferably, at least its center of the connecting member 400 is located at the position where it overlaps with the cooling medium flow path 250 when viewed from above.

[0062] In this embodiment, all of the multiple connecting members 400 provided in the electrostatic chuck 10 are arranged, as described above, at positions where their entirety overlaps with the cooling medium flow path 250. Alternatively, some of the connecting members 400 may be arranged in different positions. That is, when viewed from above, only a portion of the multiple connecting members 400 may be arranged at positions overlapping with the cooling medium flow path 250. However, to efficiently recover heat generated on the connecting members 400, it is preferable that all connecting members 400 are arranged at least partially overlapping with the cooling medium flow path 250.

[0063] In this embodiment, the plurality of connecting members 400 disposed in the electrostatic chuck 10 are all positioned with their centers located between the first sealing ring 151 and the second sealing ring 152 when viewed from above. As a result, the plurality of connecting members 400 are arranged on the outer peripheral portion of the dielectric substrate 100.

[0064] In the processing of substrate W in a semiconductor manufacturing apparatus, it is known that alternating current flowing between a pair of opposing electrodes including RF electrode 140 tends to flow towards the outer peripheral portion of dielectric substrate 100. Therefore, in this embodiment, a part of the circuit, namely the connecting member 400, is positioned in the outer peripheral portion where alternating current flows relatively easily. As a result, the flow path of alternating current can be minimized, thus enabling efficient guidance of plasma to substrate W.

[0065] The configuration of the connecting member 400 and the vent 114 described above can also be used in a structure in which only one first sealing ring 151 is provided as a sealing ring 150.

[0066] The second embodiment will be described below. Hereinafter, the parts that differ from the first embodiment will be described in detail, and the parts that are the same as those in the first embodiment will be omitted as appropriate.

[0067] Figure 7 In the middle, with Figure 4 The structure of the electrostatic chuck 10 according to this embodiment is drawn from the same perspective. Figure 7 As shown, in this embodiment, the first recess 160 is not formed to a depth that exposes the RF electrode 140. The bottom surface 162 of the first recess 160 is located closer to the surface 120 than the RF electrode 140.

[0068] The bottom surface 162 of the first recess 160 is covered by a metal plate 141. The metal plate 141 is, for example, a plate-shaped component formed of molybdenum, which is attached to the generally whole bottom surface 162. In this embodiment, the tip of the protrusion 420 is pressed against the metal plate 141.

[0069] A plurality of vias 142 provided on the dielectric substrate 100 electrically connect the metal plate 141 and the RF electrode 140. The vias 142 are formed inside holes extending in a direction perpendicular to the surface 120, and are filled, for example, with a conductive material such as tungsten. One end of the via 142 is connected to the metal plate 141, and the other end is connected to the RF electrode 140.

[0070] Thus, in this embodiment, the connecting member 400 and the RF electrode 140 are not directly connected, but indirectly connected via the metal plate 141 and the through hole 142. Even in this configuration, the same effects as described in the first embodiment can be achieved.

[0071] The present embodiment has been described above with reference to specific examples. However, the present invention is not limited to these specific examples. Regarding these specific examples, any design modifications made by those skilled in the art that possess the features of the present invention are also included within the scope of the present invention. The elements, their configurations, conditions, shapes, etc., of the foregoing specific examples are not limited to the illustrated content, but can be appropriately modified. As long as there is no technical contradiction, the elements of the foregoing specific examples can be appropriately changed and combined.

Claims

1. An electrostatic chuck, characterized in that, Features: a dielectric substrate having a mounting surface for placing the adsorbed material; RF electrodes are disposed inside the dielectric substrate; A base plate, formed of metal and bonded to the dielectric substrate; and connecting components, for electrically connecting the RF electrode and the base plate. Inside the base plate, a cooling medium flow path is formed for the cooling medium to pass through. When viewed from a direction perpendicular to the mounting surface, The connecting member is positioned such that at least a portion of it overlaps with the cooling medium flow path.

2. The electrostatic chuck according to claim 1, characterized in that, When viewed from a direction perpendicular to the mounting surface, The connecting member is positioned at its center where it overlaps with the flow path of the cooling medium.

3. The electrostatic chuck according to claim 2, characterized in that, When viewed from a direction perpendicular to the mounting surface, The connecting member is positioned where its entirety overlaps with the cooling medium flow path.

4. The electrostatic chuck according to claim 1, characterized in that, Multiple connecting components are provided. When viewed from a direction perpendicular to the mounting surface, All of the connecting members are respectively arranged in a position where at least a portion of them overlaps with the cooling medium flow path.

5. The electrostatic chuck according to claim 1, characterized in that, When viewed from a direction perpendicular to the mounting surface, The connecting member is circular in shape. The diameter of the connecting member is smaller than the width of the cooling medium flow path.

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