electrostatic chuck

Abstract

The present invention provides an electrostatic chuck that allows for easy installation of a power supply member connected to the internal electrodes of the flange. [Solution] The electrostatic chuck 10 comprises a dielectric substrate 100 having a first portion 101 having a surface 110 which is a mounting surface, and a second portion 102 that protrudes further outward from the outer peripheral end of the first portion 101 and is thinner than the first portion 101; a first internal electrode 140 provided inside the first portion 101; a second internal electrode 150 provided inside the second portion 102; a first power supply member 401 provided on the surface 120 of the dielectric substrate 100 and electrically connected to the first internal electrode 140; and a second power supply member 402 provided on the surface 120 of the dielectric substrate 100 and electrically connected to the second internal electrode 150. Both the first power supply member 401 and the second power supply member 402 are provided on the first portion 101 of the dielectric substrate 100.

Description

Technical Field

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

Background Art

[0002] For example, in a semiconductor manufacturing apparatus such as an etching apparatus, an electrostatic chuck is provided as a device for adsorbing and holding a substrate such as a silicon wafer to be processed. The electrostatic chuck includes a dielectric substrate provided with an adsorption electrode and a base plate for supporting the dielectric substrate, and has a configuration in which these are joined to each other. When a voltage is applied to the adsorption electrode, an electrostatic force is generated, and the substrate placed on the dielectric substrate is adsorbed and held.

[0003] During the processing of the substrate, an annular member called a focus ring or the like is arranged around the substrate. As described in Patent Document 1 below, the dielectric substrate may be provided with a flange portion for placing such an annular member. Among the dielectric substrates, the portion having a placement surface on which a substrate such as a silicon wafer is placed is hereinafter also referred to as the first portion. Further, the above-described flange portion provided on the dielectric substrate is hereinafter also referred to as the second portion. The second portion (flange portion) protrudes further outward from the outer peripheral end of the first portion and is a thinner portion than the first portion.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Internal electrodes are provided in both the first and second parts. These internal electrodes may be provided as "adsorption electrodes" to generate an adsorption force between the substrate and the annular member, or as "RF electrodes" to generate plasma and attract it towards the substrate.

[0006] Power is supplied to each internal electrode via a component located on the side of the dielectric substrate opposite to the mounting surface. Such a component will also be referred to as the "power supply component" below. The power supply component is, for example, a metal terminal.

[0007] In the electrostatic chuck described in Patent Document 1 above, a power supply member provided in the first part is connected to the internal electrodes of the first part, and a power supply member provided in the second part is connected to the internal electrodes of the second part.

[0008] However, since the second portion is a relatively thin part of the dielectric substrate, it is often difficult to install a power supply component in the second portion. In particular, since dielectric substrates have been getting thinner in recent years, it is expected that installing a power supply component in the second portion will become even more difficult.

[0009] The present invention has been made in view of these problems, and its objective is to provide an electrostatic chuck that allows for easy installation of a power supply member connected to the internal electrodes of the flange. [Means for solving the problem]

[0010] To solve the above problems, the electrostatic chuck according to the present invention comprises a dielectric substrate having a first portion having a mounting surface on which an object to be adsorbed is placed, and a second portion that protrudes further outward from the outer peripheral end of the first portion and is thinner than the first portion; a first internal electrode provided inside the first portion; a second internal electrode provided inside the second portion; a first power supply member provided on the side of the dielectric substrate opposite to the mounting surface and electrically connected to the first internal electrode; and a second power supply member provided on the side of the dielectric substrate opposite to the mounting surface and electrically connected to the second internal electrode, wherein both the first power supply member and the second power supply member are provided on the first portion of the dielectric substrate.

[0011] In the electrostatic chuck with the above configuration, the second power supply member, which is electrically connected to the second internal electrode of the second part (flange), is provided in the first part rather than the second part. Since the first part is thicker than the second part, both the first and second power supply members can be easily provided. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide an electrostatic chuck that allows for easy installation of a power supply member connected to the internal electrodes of the flange. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic cross-sectional view showing the configuration of the electrostatic chuck according to this embodiment. [Figure 2] This is a perspective view showing the configuration of the power supply components. [Figure 3] This diagram shows the configuration of the second internal electrode, etc. [Figure 4] This is a diagram illustrating the arrangement of gas holes and power supply components. [Figure 5] This diagram illustrates the arrangement of gas holes, power supply components, distribution channels, and sealing rings. [Modes for carrying out the invention]

[0014] This embodiment will be described below with reference to the attached drawings. To facilitate understanding of the explanation, the same reference numerals are used for identical components in each drawing whenever possible, and redundant explanations are omitted.

[0015] The electrostatic chuck 10 according to this embodiment is used to attract and hold a substrate W to be processed by electrostatic force inside a semiconductor manufacturing apparatus (not shown), such as an etching apparatus. The substrate W to be attracted is, for example, a silicon wafer. The electrostatic chuck 10 may also be used in apparatus other than semiconductor manufacturing apparatus.

[0016] Figure 1 shows a schematic cross-sectional view of the electrostatic chuck 10 in a state where the substrate W is adsorbed and held. The electrostatic chuck 10 comprises a dielectric substrate 100 and a base plate 200.

[0017] The dielectric substrate 100 is a substantially disc-shaped component made of a ceramic sintered body. The dielectric substrate 100 contains, for example, high-purity aluminum oxide (Al2O3), but may also contain other materials. The purity and type of ceramics in the dielectric substrate 100, as well as the additives, can be appropriately set considering the plasma resistance and other properties required of the dielectric substrate 100 in semiconductor manufacturing equipment.

[0018] The upper surface 110 of the dielectric substrate 100 in Figure 1 is the "mounting surface" on which the substrate W is placed. The lower surface 120 of the dielectric substrate 100 in Figure 1 is the "bonded surface" to which it is bonded to the base plate 200 via the bonding layer 300. The viewpoint from which the electrostatic chuck 10 is viewed from the surface 110 side, along a direction perpendicular to surface 110, will also be referred to as the "top view" below.

[0019] The dielectric substrate 100 has a first portion 101 and a second portion 102. The first portion 101 is a substantially cylindrical portion that extends from surface 110 toward the lower side of Figure 1 to surface 120. Such a first portion 101 can be described as the portion of the dielectric substrate 100 that has surface 110, which is the mounting surface.

[0020] The second part 102 is an annular part that protrudes further toward the outer peripheral side from the outer peripheral end of the first part 101, and is a part also referred to as the "flange part" of the dielectric substrate 100. The dotted line marked with the symbol "BD" in FIG. 1 represents the boundary between the first part 101 and the second part 102. This boundary is also referred to as the "boundary BD" hereinafter. In a top view, the boundary BD is at a position that completely overlaps with the outer surface 119 of the first part 101.

[0021] The second part 102 is thinner than the first part 101. The surface 120 described above is the lowermost surface of the first part 101 in FIG. 1 and is also the lowermost surface of the second part 102. The uppermost surface 102S of the second part 102 is at a position lower than the surface 110 in FIG. 1.

[0022] When the substrate W is processed in the semiconductor manufacturing apparatus, an annular member (not shown) called a "focus ring" or the like is arranged around the substrate W. The surface 102S of the second part 102 is a part that supports such an annular member from below. The surface 102S is a surface parallel to the surface 110.

[0023] An adsorption electrode 130 is provided inside the first part 101 of the dielectric substrate 100. The adsorption electrode 130 is a thin flat plate-like layer formed of a metal material such as tungsten, for example, and is arranged to be parallel to the surface 110. As the material of the adsorption electrode 130, in addition to tungsten, molybdenum, platinum, palladium, etc. may also be used. When a voltage is applied to the adsorption electrode 130 from the outside through a power supply path (not shown), an electrostatic force is generated between the surface 110 and the substrate W, and thereby the substrate W is adsorbed and held. As the configuration of the above power supply path, various known configurations can be adopted. The adsorption electrode 130 may be provided only one as a so-called "single-pole" electrode as in this embodiment, or may be provided two as a so-called "bipolar" electrode.

[0024] Inside the first part 101, in addition to the adsorption electrode 130 described above, a first internal electrode 140 is also embedded. The first internal electrode 140 is provided as one of a pair of counter electrodes for generating plasma in a semiconductor manufacturing apparatus. The other counter electrode is provided in a position above the electrostatic chuck 10 in the semiconductor manufacturing apparatus. When a high-frequency AC voltage is applied between these counter electrodes, plasma is generated above the substrate W, and is used for processes such as film deposition and etching on the substrate W. The first internal electrode 140 is also referred to as an "RF electrode".

[0025] The first internal electrode 140, like the adsorption electrode 130, is a thin, flat layer formed from a metallic material such as tungsten. Besides tungsten, the first internal electrode 140 may also be made of molybdenum, platinum, palladium, or other materials. The first internal electrode 140 is embedded in a position closer to the surface 120 than the adsorption electrode 130. Like the adsorption electrode 130, the first internal electrode 140 is positioned parallel to the surface 110. The first internal electrode 140 is a single electrode that is approximately circular in shape when viewed from above. The center of the first internal electrode 140 in a top view coincides with the center of the dielectric substrate 100.

[0026] The first internal electrode 140 is electrically connected to the base plate 200 via the first power supply member 401, which will be described later. Power is supplied to the first internal electrode 140 via the base plate 200 and the first power supply member 401.

[0027] A second internal electrode 150 is provided inside the second portion 102 of the dielectric substrate 100. The second internal electrode 150, together with the first internal electrode 140 mentioned earlier, is provided as one of a pair of counter electrodes for generating plasma in a semiconductor manufacturing apparatus, and is also referred to as an "RF electrode".

[0028] The second internal electrode 150 is a thin, flat layer made of the same material as the adsorption electrode 130 and the first internal electrode 140, and is arranged parallel to the surfaces 110 and 102S. As shown in Figure 3, the second internal electrode 150 is a single electrode that is approximately annular in shape when viewed from above. The center of the second internal electrode 150 in the top view coincides with the center of the dielectric substrate 100.

[0029] The second internal electrode 150 is electrically connected to the base plate 200 via the second power supply member 402, which will be described later. Power is supplied to the second internal electrode 150 via the base plate 200 and the second power supply member 402.

[0030] Returning to Figure 1 and continuing the explanation, a space SP is formed between the dielectric substrate 100 and the substrate W. When etching or other processes are performed in the semiconductor manufacturing equipment, helium gas for temperature control is supplied to the space SP from the outside via gas holes 160, etc., which will be described later. By interposing 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 gas supplied to the space SP for temperature control may be a different type of gas than helium.

[0031] A sealing ring 111 and dots 112 are provided on the mounting surface 110, and the above-mentioned space SP is formed around them.

[0032] The seal ring 111 is an annular projection provided at the outermost position of the first portion 101 to demarcate the space SP. The upper end of the seal ring 111 is part of the surface 110 and contacts the substrate W. Multiple seal rings 111 may be provided to divide the space SP. This configuration allows for individual adjustment of the helium gas pressure in each space SP, making the surface temperature distribution of the substrate W more uniform during processing.

[0033] In Figure 1, the portion labeled "116" is the bottom surface of the space SP. Hereafter, this portion will also be referred to as "bottom surface 116". The seal ring 111, along with the dot 112 described below, is formed as a result of excavating a portion of the surface 110 down to the position of the bottom surface 116.

[0034] The dots 112 are circular protrusions that extend from the bottom surface 116. Multiple dots 112 are provided and are distributed approximately evenly on the mounting surface of the dielectric substrate 100. The upper end of each dot 112 is part of the surface 110 and contacts the substrate W. By providing multiple such dots 112, the bending of the substrate W is suppressed.

[0035] Gas holes 160 are formed in the dielectric substrate 100. The gas holes 160 are through holes formed to extend perpendicular to the mounting surface 110. The end of the gas hole 160 on the surface 110 side is connected to the space SP. The gas holes 160 are part of a flow path for supplying helium gas to the space SP. Multiple gas holes 160 are formed in the dielectric substrate 100, but only two of them are shown in Figure 1.

[0036] The inner diameter of the gas hole 160 is uniform throughout, but it may vary in some parts. For example, the portion of the gas hole 160 facing the surface 120 may be enlarged, and a porous member for preventing discharge may be placed inside the enlarged portion.

[0037] The base plate 200 is a roughly disc-shaped member that supports the dielectric substrate 100. The base plate 200 is made of a metallic material such as aluminum. Of the base plate 200, the upper surface 210 in Figure 1 is the "bonded surface" that is bonded to the dielectric substrate 100 via the bonding layer 300. The outer shape of surface 210 in a top view is generally the same as the outer shape of the second portion 102 in a top view.

[0038] The bonding layer 300 is a layer provided between the dielectric substrate 100 and the base plate 200, and it bonds the two together. The bonding layer 300 is made 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 made by curing another type of adhesive. In any case, it is preferable to use a material with the highest possible thermal conductivity for the bonding layer 300 so that the thermal resistance between the dielectric substrate 100 and the base plate 200 is reduced.

[0039] An insulating film may be formed on the surface of the base plate 200. As the insulating film, for example, an alumina film formed by thermal spraying can be used. By covering the surface of the base plate 200 with an insulating film, the dielectric strength of the base plate 200 can be increased.

[0040] A refrigerant channel 250 is formed inside the base plate 200 for passing a refrigerant. When etching or other processes are performed in the semiconductor manufacturing equipment, a refrigerant is supplied from the outside to the refrigerant channel 250, thereby cooling the base plate 200. During processing, the heat generated in the substrate W is transferred to the refrigerant 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 refrigerant. The supply and discharge of refrigerant to and from the refrigerant channel 250 is performed through an opening (not shown) formed on the surface 220 of the base plate 200 opposite to the surface 210. The refrigerant channel 250 is formed to pass not only through the area overlapping with the first portion 101 in a top view, but also through the area overlapping with the second portion 102. Therefore, the annular member placed on the surface 102S is also cooled by the refrigerant passing through the refrigerant channel 250.

[0041] Gas holes 260 are formed in the base plate 200. The gas holes 260 are formed to extend in a direction perpendicular to the mounting surface 110, and extend from the surface 210 to the distribution channel 265 described later. The gas holes 260 are formed at positions that overlap with the gas holes 160 when viewed from above, and are in communication with the gas holes 160 via through holes provided in the bonding layer 300. Together with the gas holes 160 of the dielectric substrate 100, the gas holes 260 form part of the channel for supplying helium gas to the space SP on the mounting surface side.

[0042] The inner diameter of the gas hole 260 is uniform throughout, but it may vary in some parts. For example, the portion of the gas hole 260 facing the surface 210 may be enlarged, and a porous material to prevent discharge may be placed inside the enlarged portion.

[0043] A distribution channel 265 is formed inside the base plate 200. The distribution channel 265 is a channel for distributing helium gas to each gas hole 260. The distribution channel 265 is routed parallel to the surface 210 and is connected to the lower end of each gas hole 260.

[0044] Helium gas supplied from an external source flows into the distribution channel 265 through a channel (not shown) formed inside the base plate 200, and is then distributed from the distribution channel 265 to each gas hole 260. By forming the distribution channel 265 inside the base plate 200, the number of parts that receive helium gas from an external source can be reduced.

[0045] As described above, the base plate 200 has a relatively complex internal structure, with refrigerant flow paths 250, distribution flow paths 265, and gas holes 260 formed inside. To facilitate the formation of the refrigerant flow paths 250, etc., 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, consisting of a first member 201, a second member 202, and a third member 203. Each member is joined by welding, but they 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 it may be two.

[0046] The first member 201, the second member 202, and the third member 203 are arranged in this order along a direction perpendicular to the mounting surface 110. The first member 201 is the part of the base plate 200 that is closest to the dielectric substrate 100. The surface 210 mentioned earlier is part of the first member 201. The third member 203 is the part of the base plate 200 that is opposite to the dielectric substrate 100. The surface 220 mentioned earlier is part of the third member 203. The second member 202 is located between the first member 201 and the third member 203.

[0047] The joint boundary B1 between the first member 201 and the second member 202 is parallel to surfaces 110 and 210. The joint boundary B2 between the second member 202 and the third member 203 is also parallel to surfaces 110 and 210.

[0048] In this embodiment, both the distribution channel 265 and the gas hole 260 are formed entirely in the first member 201. The distribution channel 265 is an annular groove that was pre-formed along the surface of the first member 201 that will become the joining boundary B1 before joining the members. In this way, by pre-forming a groove on the surface of the first member 201 and joining the second member 202 so as to cover that surface, the distribution channel 265 along the groove can be easily formed inside the base plate 200. Note that the groove that will become the distribution channel 265 may be formed on the surface of the second member 202 that will become the joining boundary B1, rather than on the surface of the first member 201.

[0049] As shown in Figure 1, the refrigerant flow path 250 in this embodiment is formed entirely in the second member 202. The refrigerant flow path 250 is a groove that was pre-formed along the surface of the second member 202 that will become the joining boundary B2 before joining the members. In this way, by pre-forming a groove on the surface of the second member 202 and joining the third member 203 so as to cover that surface, the refrigerant flow path 250 along the groove can be easily formed inside the base plate 200. Note that the groove that will become the refrigerant flow path 250 may also be formed on the surface of the second member 202 that will become the joining boundary B1.

[0050] As previously mentioned, the first internal electrode 140 and the second internal electrode 150, both located inside the dielectric substrate 100, function as RF electrodes and are electrically connected to the base plate 200. The first internal electrode 140 and the base plate 200 are electrically connected via the first power supply member 401. The second internal electrode 150 and the base plate 200 are electrically connected via the second power supply member 402.

[0051] A recess 170 is formed on the surface 120 of the dielectric substrate 100 that faces the base plate 200. The recess 170 is a portion of the surface 120 that has been recessed toward the surface 110 in order to allow the first power supply member 401 to be placed therein. The first internal electrode 140 is exposed at the bottom surface of the recess 170. In a top view, the shape of the recess 170 is circular, and a roughly cylindrical space is formed inside it.

[0052] A recess 270 is formed on the surface 210 of the base plate 200 that faces the dielectric substrate 100. The recess 270 is formed on the surface 210 in the portion that overlaps with the recess 170 when viewed from above. The recess 270 is a portion of the surface 210 that has been recessed toward the surface 220 in order to allow the first power supply member 401 to be placed therein. The metal portion of the base plate 200 is exposed throughout the inside of the recess 270. The shape of the recess 270 when viewed from above is circular, and a roughly cylindrical space is formed inside it. The central axis of the recess 270 coincides with the central axis of the recess 170. In Figure 1, the lower end of the recess 270 is located further below the lower end of the distribution channel 265.

[0053] A circular opening is formed in the joint layer 300 between the recess 170 and the recess 270. The recess 170 and the recess 270 are connected through this opening, and the entire area forms a single space. The first power supply member 401 is housed inside the recess 170 and the recess 270.

[0054] The first power supply member 401 is in contact with the first internal electrode 140, which is exposed on the bottom surface of the recess 170. The first power supply member 401 is also in contact with the metal portion of the base plate 200, which is exposed on the bottom surface of the recess 270. The first power supply member 401, positioned in this manner, electrically connects the first internal electrode 140 and the metal portion of the base plate 200. Multiple first power supply members 401 are provided on the surface 120 of the dielectric substrate 100, but only two of them are shown in Figure 1.

[0055] A recess 180 is formed on the surface 120 of the dielectric substrate 100 that faces the base plate 200. The recess 180 is a portion of the surface 120 that has been recessed toward the surface 110 in order to allow the second power supply member 402 to be placed therein. At the bottom surface of the recess 180, a connection portion 151 connected to the second internal electrode 150 is exposed. The connection portion 151 will be described later. In a top view, the shape of the recess 180 is circular, and a roughly cylindrical space is formed inside it.

[0056] A recess 280 is formed on the surface 210 of the base plate 200 that faces the dielectric substrate 100. The recess 280 is formed on the surface 210 in the portion that overlaps with the recess 180 when viewed from above. The recess 280 is a portion of the surface 210 that has been recessed toward the surface 220 in order to allow the second power supply member 402 to be placed therein. The metal portion of the base plate 200 is exposed throughout the inside of the recess 280. The shape of the recess 280 when viewed from above is circular, and a roughly cylindrical space is formed inside it. The central axis of the recess 280 coincides with the central axis of the recess 180. In Figure 1, the lower end of the recess 280 is located further below the lower end of the distribution channel 265.

[0057] A circular opening is formed in the joint layer 300 between the recess 180 and the recess 280. The recess 180 and the recess 280 are connected through this opening, and the entire area forms a single space. The second power supply member 402 is housed inside the recess 180 and the recess 280.

[0058] The second power supply member 402 is in contact with the connection portion 151, which is exposed on the bottom surface of the recess 180. The second power supply member 402 is also in contact with the metal portion of the base plate 200, which is exposed on the bottom surface of the recess 280. The second power supply member 402, positioned in this manner, electrically connects the second internal electrode 150 and the metal portion of the base plate 200. Multiple second power supply members 402 are provided on the surface 120 of the dielectric substrate 100, but only two of them are shown in Figure 1.

[0059] The first power supply member 401 ensures that the potential of the first internal electrode 140 during processing of the substrate W is the same as the potential of the base plate 200. Similarly, the second power supply member 402 ensures that the potential of the second internal electrode 150 during processing of the substrate W is the same as the potential of the base plate 200. The first power supply member 401 and the second power supply member 402 are identical in shape. Hereinafter, they will also be collectively referred to as "power supply member 400". The power supply member 400 is a substantially cylindrical member formed from a fibrous metal material.

[0060] As shown in Figure 2, the power supply member 400 has a substantially cylindrical main body portion 410 and a plurality of protrusions 420, and the entire body is integrally formed from a fibrous metal member. The protrusions 420 are substantially cylindrical projections formed so as to extend from the surface of the main body portion 410 facing the dielectric substrate 100, and further toward the dielectric substrate 100. In this embodiment, a total of four protrusions 420 are formed, but the number of protrusions 420 may be different.

[0061] The power supply member 400, which is made of fibrous metal material, has some degree of permeability, allowing fluids such as air to enter its interior. In other words, the fibrous metal material is not sufficiently dense, and there are gaps between the fibers. With this configuration, each part of the power supply member 400, including the protruding portion 420, is an elastic body that can be easily deformed by external forces.

[0062] When not subjected to external force, the vertical dimension of the power supply member 400 (in the direction in which the protrusion 420 extends) is larger than the dimension in the same direction in the state shown in Figure 2. In other words, the power supply member 400 is housed inside the recesses 170 and 180 in a compressed state along the direction from the dielectric substrate 100 toward the base plate 200. The tip of each protrusion 420 is elastically deformed so as to be crushed when pressed against the first internal electrode 140 or the connection portion 151.

[0063] The power supply member 400 is pressed against the first internal electrode 140, etc., by its own restoring force. Therefore, even if thermal expansion or contraction occurs in various parts of the electrostatic chuck 10 during processing of the substrate W, the electrical connection between the first internal electrode 140 and the base plate 200, and the electrical connection between the second internal electrode 150 and the base plate 200 are always maintained. The shape of the power supply member 400 may be different from that shown in Figure 2.

[0064] Figure 3 schematically shows the configuration of the second internal electrode 150 and the connection part 151 connected to it, in a top view. The entire second internal electrode 150 is located inside the second part 102. On the other hand, the second power supply member 402 for supplying power to the second internal electrode 150 is located inside the first part 101, not the second part 102. The second internal electrode 150 and the second power supply member 402 are electrically connected via the connection part 151.

[0065] The connecting portion 151 extends linearly from the inner circumference end of the second internal electrode 150 toward the second power supply member 402 further toward the inner circumference. The connecting portion 151 is at the same height as the second internal electrode 150 and is parallel to the second internal electrode 150. The connecting portion 151 is made of the same material as the second internal electrode 150 and is formed as an electrode layer integrated with the second internal electrode 150. The number of connecting portions 151 is the same as the number of second power supply members 402. As mentioned above, the upper end of the second power supply member 402 abuts against each connecting portion 151.

[0066] As described above, the electrostatic chuck 10 according to this embodiment includes a first power supply member 401 electrically connected to the first internal electrode 140 and a second power supply member 402 electrically connected to the second internal electrode 150, and both the first power supply member 401 and the second power supply member 402 are provided on the first portion 101 of the dielectric substrate 100.

[0067] Since the second internal electrode 150 is located inside the second portion 102, it might seem that the second power supply member 402 connected to it should also be located in the second portion 102. However, since the second portion 102 is a relatively thin part of the dielectric substrate 100, it is often difficult to provide the second power supply member 402 in the second portion 102. In particular, since dielectric substrates 100 have tended to become thinner in recent years, it is likely that providing the second power supply member 402 in the second portion 102 will become even more difficult.

[0068] Therefore, in the electrostatic chuck 10 according to this embodiment, both the first power supply member 401 and the second power supply member 402 are provided in the first portion 101. Since the first portion 101 is thicker than the second portion 102, both the first power supply member 401 and the second power supply member 402 can be easily provided.

[0069] Figure 4 shows a top view of the arrangement of the gas holes 160, the first power supply member 401, and the second power supply member 402 on the dielectric substrate 100. Multiple of each of these are provided and arranged in a ring shape along the circumferential direction.

[0070] The dotted line DL1 shown in Figure 4 is a hypothetical circle drawn to pass through the centers of all the second power supply members 402. In the top view, the center of the circle of dotted line DL1 coincides with the center of the first part 101. The second power supply members 402 are arranged in a circular and equally spaced pattern along this dotted line DL1.

[0071] When the substrate W is being processed, Joule heat is generated in the second power supply member 402. In other words, the second power supply member 402 acts as a heat source. In this embodiment, the variation in the in-plane temperature distribution of the substrate W is suppressed by arranging the second power supply members 402, which are heat sources, in a ring shape.

[0072] Furthermore, as a result of arranging all the second power supply members 402 along the dotted line DL1, the length of the radial connection portion 151 is the same for all connection portions 151. In this configuration, the magnitude of Joule heat generated in the second power supply members 402 and the connection portions 151 is uniform over the entire circumference, so variations in the in-plane temperature distribution of the substrate W can be further suppressed.

[0073] The dotted line DL2 shown in Figure 4 is a hypothetical circle drawn to pass through the centers of all the gas holes 160. In the top view, the center of the circle of dotted line DL2 coincides with the center of the first part 101. Also, the diameter of the circle of dotted line DL2 is smaller than the diameter of the circle of dotted line DL1. The gas holes 160 are arranged in a ring shape and at equal intervals along this dotted line DL2.

[0074] In the vicinity of the gas holes 160, the substrate W is cooled by the influence of the supplied helium gas. In other words, the gas holes 160 act as a cooling source. In this embodiment, the variation in the in-plane temperature distribution of the substrate W is further suppressed by arranging the gas holes 160, which are the cooling source, in an annular shape.

[0075] The dotted line DL3 shown in Figure 4 is a hypothetical circle drawn to pass through the centers of all the first power supply members 401. In the top view, the center of the circle of dotted line DL3 coincides with the center of the first part 101. Furthermore, the diameter of the circle of dotted line DL3 is even smaller than the diameter of the circle of dotted line DL2. The first power supply members 401 are arranged along this dotted line DL3 in an annular shape and at equal intervals.

[0076] When the substrate W is being processed, Joule heat is generated in the first power supply member 401, just like in the second power supply member 402. In other words, the first power supply member 401 also becomes a heat source. In this embodiment, the variation in the in-plane temperature distribution of the substrate W is further suppressed by arranging the first power supply members 401, which are heat sources, in a ring shape.

[0077] Multiple second power supply members 402 are positioned on the outer periphery of multiple first power supply members 401. In this configuration, each connection portion 151 becomes shorter and its electrical resistance decreases, thereby improving power efficiency.

[0078] Multiple first power supply members 401 are positioned on the inner circumference side of the multiple gas holes 160, and multiple second power supply members 402 are positioned on the outer circumference side of the multiple gas holes 160. By positioning the gas holes 160, which are cooling sources, between the first power supply members 401 and the second power supply members 402, which are heat sources, it is possible to prevent excessive temperature rise on the substrate W.

[0079] Furthermore, if the length of the connection portion 151 (and the resulting electrical resistance) is not a problem, the positions of the first power supply member 401 and the second power supply member 402 may be swapped. In other words, the multiple first power supply members 401 may be positioned on the outer circumference side of the multiple gas holes 160, and the multiple second power supply members 402 may be positioned on the inner circumference side of the multiple gas holes 160.

[0080] In this embodiment, the first power supply member 401, the gas hole 160, the second power supply member 402, and the gas hole 160 are arranged in this order repeatedly along the circumferential direction. By arranging the heating source and the cooling source alternately along the circumferential direction, a localized temperature rise of the substrate W can be suppressed.

[0081] Figure 5 shows the arrangement of the gas holes 160, the first power supply member 401, and the second power supply member 402 on the dielectric substrate 100 in a top view, similar to Figure 4. Figure 5 also shows the arrangement of the distribution channel 265 and the seal ring 111.

[0082] As shown in Figure 5, both the first power supply member 401 and the second power supply member 402 in this embodiment are formed in positions that do not overlap with the distribution channel 265 when viewed from above. In other words, the distribution channel 265 is positioned to avoid being directly beneath the first power supply member 401 and the second power supply member 402, which are heat sources. In this configuration, heat dissipation from the first power supply member 401, etc., is not obstructed by the distribution channel 265. This makes it possible to suppress excessive temperature rise on the substrate W.

[0083] In this embodiment, both the first power supply member 401 and the second power supply member 402 are positioned so as not to overlap with the seal ring 111 when viewed from above. In this configuration, heat from the heat source, such as the first power supply member 401, is not directly transferred to the substrate W via the seal ring 111. This makes it possible to suppress an excessive temperature rise on the substrate W. If another seal ring is provided on the inner circumference side of the seal ring 111, the first power supply member 401 and the second power supply member 402 should be positioned so as not to overlap with either seal ring when viewed from above.

[0084] In this embodiment, both the first power supply member 401 and the second power supply member 402 are provided as members for electrically connecting the first internal electrode 140, etc., to the base plate 200. Alternatively, the first power supply member 401 and the second power supply member 402 may be electrically connected to an external power source instead of the base plate 200. Furthermore, the second internal electrode 150 provided in the second portion 202 may be an RF electrode as in this embodiment, but it may also be an adsorption electrode for adsorbing an annular member.

[0085] The embodiments have been described above with reference to specific examples. However, this disclosure is not limited to these specific examples. Modifications made to these specific examples by those skilled in the art are also included within the scope of this disclosure, as long as they retain the features of this disclosure. The elements, their arrangement, conditions, shapes, etc., of each of the aforementioned specific examples are not limited to those illustrated and can be modified as appropriate. The elements of each of the aforementioned specific examples can be combined in different ways as appropriate, as long as no technical inconsistencies arise. [Explanation of symbols]

[0086] 10: Electrostatic Chuck 101: Part 1 102:Second part 110,120: face 140: 1st internal electrode 111: Seal ring 150:Second internal electrode 160: Gas hole 200: Base plate 265: Distribution channel 401: First power supply component 402: Second power supply component W: Circuit board

Claims

1. A dielectric substrate having a first portion having a mounting surface on which an object to be adsorbed is placed, and a second portion that protrudes further outward from the outer peripheral end of the first portion and is thinner than the first portion, A first internal electrode provided inside the first part, A second internal electrode provided inside the second part, A first power supply member is provided on the surface of the dielectric substrate opposite to the surface described above, and is electrically connected to the first internal electrode. The dielectric substrate comprises a second power supply member provided on the surface opposite to the mounting surface described above, and electrically connected to the second internal electrode, An electrostatic chuck characterized in that both the first power supply member and the second power supply member are provided on the first portion of the dielectric substrate.

2. The electrostatic chuck according to claim 1, characterized in that a plurality of the second power supply members are provided and are arranged in an annular pattern along the circumferential direction.

3. The electrostatic chuck according to claim 2, characterized in that a plurality of the first power supply members are also provided and are arranged in an annular pattern along the circumferential direction.

4. The electrostatic chuck according to claim 3, characterized in that the plurality of second power supply members are arranged at a position that is on the outer circumference side of the plurality of first power supply members.

5. The electrostatic chuck according to claim 3, characterized in that a plurality of gas holes are formed in the dielectric substrate, and these are arranged in an annular shape along the circumferential direction.

6. One of the multiple first power supply members and the multiple second power supply members is positioned on the inner circumference side of the multiple gas holes. The electrostatic chuck according to claim 5, characterized in that the other of the plurality of first power supply members and the plurality of second power supply members is positioned on the outer circumference side of the plurality of gas holes.

7. The electrostatic chuck according to claim 5, characterized in that the first power supply member, the gas hole, the second power supply member, and the gas hole are arranged in this order repeatedly along the circumferential direction.

8. The dielectric substrate has a plurality of gas holes formed therein. When viewed from a direction perpendicular to the mounting surface, The electrostatic chuck according to claim 1, characterized in that the first power supply member and the second power supply member are formed in positions that do not overlap with the distribution channel for distributing gas to the respective gas holes.

9. Part 1 includes, A seal ring is provided, which is an annular projection whose tip surface is part of the aforementioned mounting surface. When viewed from a direction perpendicular to the mounting surface, The electrostatic chuck according to claim 1, characterized in that the first power supply member and the second power supply member are arranged in positions that do not overlap with the seal ring.

10. The base plate, which is a metal member that supports the dielectric substrate, further comprises The electrostatic chuck according to claim 1, characterized in that both the first power supply member and the second power supply member are electrically connected to the base plate.

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