Electrostatic chuck, semiconductor manufacturing device, and plasma treatment device

Abstract

The present invention addresses the problem of providing a semiconductor manufacturing device, a plasma treatment device, and an electrostatic chuck capable of suppressing abnormal discharge of an electrode. The present invention is provided with: a base (10); a placement member (13) that is equipped with a placement surface (15) on which an object to be placed is placed; and a first conductive layer (11) that is provided inside the placement member (13). A second conductive layer (12) formed from the base (10) or provided between the base (10) and the first conductive layer (11) is disposed along the placement surface (15) together with the first conductive layer (11). When the placement surface (15) is viewed in a plan view, the second conductive layer (12) overlaps a range that includes the first conductive layer (11), and the second conductive layer (12) includes a region not overlapping the first conductive layer (11).

Description

Electrostatic chuck, semiconductor manufacturing apparatus, and plasma processing apparatus

[0001] The present invention relates to an electrostatic chuck, a semiconductor manufacturing apparatus, and a plasma processing apparatus.This application claims priority to Japanese Patent Application No. 2024-134830, filed on August 13, 2024, the contents of which are incorporated herein by reference.

[0002] When a substrate such as a semiconductor wafer, a glass substrate, or an insulating substrate is processed, or a film is formed on the substrate, it is necessary to hold the substrate at a predetermined position. When a voltage is applied to the internal electrode of an electrostatic chuck, an electrostatic attraction force is generated, and the substrate can be supported substantially parallel to the internal electrode (see, for example, Patent Documents 1 and 2).

[0003] JP 2015-88743 A JP 2011-222977 A

[0004] However, in conventional electrostatic chucks, if a high voltage is applied to the electrode, there is a risk of abnormal discharge.

[0005] An object of the present invention is to provide an electrostatic chuck, a semiconductor manufacturing apparatus, and a plasma processing apparatus that are capable of suppressing abnormal discharge at an electrode.

[0006] The present invention includes the following aspects: [1] An electrostatic chuck comprising: a mounting member having a base and a mounting surface on which an object to be placed is placed; and a first conductive layer provided inside the mounting member, wherein a second conductive layer formed by the base or a second conductive layer provided between the base and the first conductive layer is arranged along the mounting surface together with the first conductive layer, and the second conductive layer overlaps and includes the first conductive layer in a plan view relative to the mounting surface, and the second conductive layer includes a region that does not overlap with the first conductive layer. [2] The electrostatic chuck according to [1], wherein, in a plan view relative to the mounting surface, the region of the second conductive layer overlaps and includes an outer peripheral end of the first conductive layer, and the outer peripheral end of the second conductive layer includes a region that does not overlap with the first conductive layer. [3] The electrostatic chuck according to [1] or [2], characterized in that a through hole extending from the base to the mounting surface is formed, and in a plan view with respect to the mounting surface, a region of the second conductive layer overlaps with an end of the first conductive layer including an end of the first conductive layer on the through-hole side, and the end of the second conductive layer on the through-hole side includes a region that does not overlap with the first conductive layer. [4] The electrostatic chuck according to [2], characterized in that, in a cross-sectional view perpendicular to the mounting surface, the distance between an outer peripheral end of the first conductive layer and an outer peripheral end of the second conductive layer is 0.01 mm or more and 5.0 mm or less. [5] The electrostatic chuck according to [3], characterized in that, in a cross-sectional view perpendicular to the mounting surface, the distance between an end of the first conductive layer on the through-hole side and an end of the second conductive layer on the through-hole side is 0.01 mm or more and 5.0 mm or less. [6] The electrostatic chuck according to any one of [1] to [5], characterized in that the first conductive layer is an attraction electrode that attracts the object to be mounted. [7] The electrostatic chuck according to [3] or [5], characterized in that the through-hole has an insulator provided along the inner wall of the through-hole. [8] The electrostatic chuck according to [3], [5] or [7], characterized in that the through-hole is a flow path for a heat transfer gas. [9] The electrostatic chuck according to [3], [5] or [7], characterized in that the through-hole has an elevating pin for elevating and lowering an object to be placed.

[10] The electrostatic chuck according to any one of [1] to [9], wherein the second conductive layer is connected to a high-frequency power source.

[11] The electrostatic chuck according to any one of [3], [5], or [7] to [9], wherein an insulating porous body is provided in the through hole.

[12] The electrostatic chuck according to any one of [1] to

[11] , wherein the mounting surface includes a thermally sprayed film.

[13] The electrostatic chuck according to [7], wherein the insulator is a sleeve, and the outer periphery of the sleeve has a protrusion extending along the mounting surface.

[14] A semiconductor manufacturing apparatus comprising the electrostatic chuck according to any one of [1] to

[13] .

[15] A plasma processing apparatus comprising the electrostatic chuck according to any one of [1] to

[13] .

[0007] According to the present invention, it is possible to provide an electrostatic chuck, a semiconductor manufacturing apparatus, and a plasma processing apparatus that are capable of suppressing abnormal discharge in an electrode.

[0008] Fig. 1 is a cross-sectional view showing an example of an electrostatic chuck; Fig. 2 is a cross-sectional view showing an example of an electrostatic chuck having a through-hole; Fig. 3 is a cross-sectional view showing an example of an electrostatic chuck having an insulator in the through-hole; Fig. 4 is a cross-sectional view showing an example of an electrostatic chuck having lift pins; Fig. 5 is a cross-sectional view showing an example of an electrostatic chuck having an insulator on the base side; Fig. 6 is a cross-sectional view showing an example of an electrostatic chuck having a porous body; Fig. 7 is a cross-sectional view showing an example of an electrostatic chuck having a protrusion on the sleeve;

[0009] The present invention will be described below based on preferred embodiments. Note that the dimensional ratios of components in the drawings may not be the same as those in reality.

[0010] 1 is a cross-sectional view schematically illustrating an example of an electrostatic chuck 100. The electrostatic chuck 100 includes a base 10, a mounting member 13 having a mounting surface 15 on which an object is placed, and a first conductive layer 11 provided inside the mounting member 13. The electrostatic chuck 100 further includes a second conductive layer 12 disposed along the mounting surface 15 together with the first conductive layer 11.

[0011] The second conductive layer 12 may be a second conductive layer 12 formed from the base 10, or may be a second conductive layer 12 provided between the base 10 and the first conductive layer 11. The second conductive layer 12 in the illustrated example is formed on the surface of the base 10. If the base 10 is conductive, the base 10 itself may be the second conductive layer 12. Furthermore, if the second conductive layer 12 is provided between the base 10 and the first conductive layer 11, the second conductive layer 12 may be separated from the base 10.

[0012] The first conductive layer 11 may be the electrode closest to the mounting surface 15. The second conductive layer 12 may be the electrode formed by the base 10 or the electrode closest to the base 10. If the second conductive layer 12 is not formed by the base 10 itself, the base 10 may be formed from an electrical insulator or a semiconductor. The material of the base 10 is not particularly limited, but it can be formed from metals, alloys, etc. containing elements such as silver, aluminum, zirconium, silicon, tin, indium, and titanium, or ceramics. Ceramics include oxide-based ceramics and non-oxide-based ceramics (nitride-based ceramics, silicate compound-based ceramics, carbide-based ceramics, phosphate compounds, etc.). Specific examples of ceramic materials include boron nitride, aluminum nitride, aluminum oxide, yttrium oxide, zirconium oxide, silicon oxide, tin oxide, indium oxide, quartz glass, soda glass, lead glass, borosilicate glass, zirconium nitride, titanium oxide, silicon carbide, etc. The base 10 may be made of one material alone or a mixture of two or more materials.

[0013] Between the first conductive layer 11 and the second conductive layer 12, other conductive layers, electrodes, heaters, etc. may be laminated.

[0014] In the electrostatic chuck 100, the second conductive layer 12 overlaps the first conductive layer 11 in a plan view with respect to the mounting surface 15, and the second conductive layer 12 includes an area that does not overlap with the first conductive layer 11. Here, the plan view with respect to the mounting surface 15 refers to the planar shape of the mounting surface 15 when viewed from a direction perpendicular to the mounting surface 15. In the illustrated example, the direction perpendicular to the mounting surface 15 is the up-down direction.

[0015] When the electrostatic chuck 100 operates, a voltage is applied to each of the first conductive layer 11 and the second conductive layer 12. The second conductive layer 12 includes a region that does not overlap with the first conductive layer 11. If the end 11a of the first conductive layer 11, which is disposed between the mounting surface 15 and the second conductive layer 12, protrudes outward from the end 12a of the second conductive layer 12, discharge may be induced. By including a region in the end 12a of the second conductive layer 12 that does not overlap with the first conductive layer 11, abnormal discharge in the electrode can be further suppressed. In this case, the end 12a of the second conductive layer 12 protrudes outward from the end 11a of the first conductive layer 11. It is preferable that the end 11a, 12a of the first conductive layer 11 and the second conductive layer 12 satisfy the above-described positional relationship over the entire periphery. It is preferable that the area of ​​the first conductive layer 11 is smaller than the area of ​​the second conductive layer 12.

[0016] The object to be placed on the mounting surface 15 is not particularly limited, but examples thereof include semiconductors such as silicon (Si), glass, ceramics, and insulating materials. The object to be attracted may be a semiconductor wafer. Applications of the electrostatic chuck 100 are not particularly limited, but examples thereof include semiconductor manufacturing equipment and plasma processing equipment.

[0017] The mounting surface 15 may have a configuration in which at least one type of dielectric material 14 is laminated on the first conductive layer 11. The dielectric material 14 is not particularly limited, but examples thereof include resins and ceramics. Two or more types of dielectric materials 14 may be laminated or mixed between the first conductive layer 11 and the mounting surface 15 to form a composite. The mounting surface 15 preferably includes a thermal sprayed film.

[0018] Examples of the resin layer of the dielectric material 14 include a resin film and a resin coating. The resin layer may contain additives other than resin, ceramic particles, etc. The dielectric material 14 may include an adhesive layer, an adhesion layer, etc. The dielectric material 14 may have irregularities on the mounting surface 15, and these irregularities may be a ceramic layer or a resin layer. The upper surface of the convex portion of the mounting surface 15 is preferably a flat surface along the mounting surface 15, in which case an object to be placed can be placed on the upper surface of the convex portion.

[0019] The resin material for forming the resin film of the dielectric material 14 is not particularly limited as long as it has electrical insulation properties, but examples thereof include polyesters such as polyethylene terephthalate, polyolefins such as polyethylene and polypropylene, polyimide, polyamide, polyamideimide, polyethersulfone, polyphenylene sulfide, polyetherketone, polyetherimide, triacetyl cellulose, silicone rubber, and fluorine-based resins such as polytetrafluoroethylene.

[0020] The resin constituting the resin coating film or adhesive layer of the dielectric material 14 is not particularly limited as long as it has electrical insulation properties, and examples thereof include epoxy resin, phenol resin, acrylic resin, styrene-based block copolymer, polyamide resin, acrylonitrile-butadiene copolymer, polyester resin, polyimide resin, silicone resin, amine compound, bismaleimide compound, etc. These resins may be used alone or in combination of two or more.

[0021] The ceramic material constituting the ceramic layer of the dielectric material 14 is not particularly limited, and examples thereof include various oxide ceramics and non-oxide ceramics (nitride ceramics, silicate compound ceramics, carbide ceramics, phosphate compounds, etc.). Specific examples of ceramic materials include boron nitride, aluminum nitride, aluminum oxide, yttrium oxide, zirconium oxide, silicon oxide, tin oxide, indium oxide, quartz glass, soda glass, lead glass, borosilicate glass, zirconium nitride, titanium oxide, silicon carbide, etc. The ceramic material of the dielectric material 14 may be used alone or in combination of two or more.

[0022] An intermediate layer containing at least one of an organic insulating resin and an inorganic insulating resin may be laminated between the resin layer and the ceramic layer of the dielectric material 14. Examples of organic insulating resins include, but are not limited to, polyimide resins, epoxy resins, and acrylic resins. Examples of inorganic insulating resins include, but are not limited to, silane resins and silicone resins. Here, organic insulating resins refer to polymeric materials containing carbon elements in their main chains, and inorganic insulating resins refer to polymeric materials not containing carbon elements in their main chains.

[0023] The intermediate layer of the dielectric material 14 may contain at least one of organic or inorganic polysilazane, inorganic powder filler, and fibrous filler. Examples of powder fillers include, but are not limited to, alumina, silica, yttria, etc. Examples of fibrous fillers include, but are not limited to, vegetable fibers such as pulp, inorganic fibers such as alumina, and organic fibers such as aramid and polytetrafluoroethylene.

[0024] The first conductive layer 11 and the second conductive layer 12 preferably function as electrodes. Examples of the electrode functions include an adsorption electrode, a control electrode, and a heating electrode. The adsorption electrode is an electrode for adsorbing an object to be placed. The control electrode is an electrode for controlling an electric field, etc. The heating electrode is an electrode for controlling the temperature of the object to be placed. The second conductive layer 12 may be connected to a high-frequency power source.

[0025] The material of the first conductive layer 11 and the second conductive layer 12 is not particularly limited, but examples thereof include metals such as copper, aluminum, gold, silver, platinum, chromium, nickel, and tungsten, alloys containing at least one of these metals, and mixtures of these with ceramic materials. The materials of the first conductive layer 11 and the second conductive layer 12 may be the same or different from each other.

[0026] 1 , in a plan view with respect to the mounting surface 15, the second conductive layer 12 overlaps the first conductive layer 11, including the outer peripheral end 11a thereof, and the outer peripheral end 12a of the second conductive layer 12 includes a region that does not overlap with the first conductive layer 11. In this way, the end 11a of the first conductive layer 11 and the end 12a of the second conductive layer 12 may be outer peripheral ends.

[0027] In a cross-sectional view perpendicular to the mounting surface 15, the distance between the outer peripheral end 11a of the first conductive layer 11 and the outer peripheral end 12a of the second conductive layer 12 is preferably greater than 0.00 mm, more preferably 0.01 mm to 5.0 mm, even more preferably 0.01 mm to 2.0 mm, and particularly preferably 0.01 mm to 1.0 mm. When the distance is equal to or greater than the lower limit, abnormal discharge is easily suppressed, and when the distance is equal to or less than the upper limit, the area and functionality of the first conductive layer 11 are easily ensured. For example, when the first conductive layer 11 is an attraction electrode, it is easy to uniformly hold the object to be mounted.

[0028] 2 is a cross-sectional view showing an example of an electrostatic chuck 101 having a through hole 20. In this electrostatic chuck 101, a through hole 20 is formed extending from a base 10 to a mounting surface 15. In a plan view of the mounting surface 15, a region of the second conductive layer 12 overlaps with an end 11b of the first conductive layer 11 on the through hole 20 side, and an end 12b of the second conductive layer 12 on the through hole 20 side includes a region that does not overlap with the first conductive layer 11.

[0029] When the electrostatic chuck 101 is in operation, if the end 11b of the first conductive layer 11 on the through hole 20 side protrudes outward beyond the end 12b of the second conductive layer 12 on the through hole 20 side, discharge may be induced. By including a region in the end 12b of the second conductive layer 12 on the through hole 20 side that does not overlap with the first conductive layer 11, abnormal discharge in the electrode can be suppressed. In this case, the end 12b of the second conductive layer 12 on the through hole 20 side is in a positional relationship in which it protrudes outward beyond the end 11b of the first conductive layer 11 on the through hole 20 side. It is preferable that the above positional relationship be satisfied between the ends 11b, 12b around the entire circumference of the through hole 20.

[0030] In a cross-sectional view perpendicular to the mounting surface 15, the distance between the end 11b of the first conductive layer 11 on the through-hole 20 side and the end 12b of the second conductive layer 12 on the through-hole 20 side is preferably greater than 0.0 mm, more preferably 0.01 mm to 5.0 mm, even more preferably 0.01 mm to 2.0 mm, and particularly preferably 0.01 mm to 1.0 mm. When this distance is equal to or greater than the lower limit, abnormal discharge is easily suppressed, and when this distance is equal to or less than the upper limit, the area and functionality of the first conductive layer 11 are easily ensured. For example, when the first conductive layer 11 is an attraction electrode, it is easy to uniformly hold the object to be mounted.

[0031] Around all of the through holes 20 provided in the base 10 or the like of the electrostatic chuck 101, the end 12b of the second conductive layer 12 on the through hole 20 side may include an area that does not overlap with the first conductive layer 11. Alternatively, around some of the through holes 20, the end 12b of the second conductive layer 12 on the through hole 20 side may include an area that does not overlap with the first conductive layer 11. The first conductive layer 11 may overlap some of the through holes 20. For example, holes in an electrical circuit extending in a direction perpendicular to the mounting surface 15 may overlap an area of ​​the first conductive layer 11.

[0032] 3 is a cross-sectional view showing an example of an electrostatic chuck 102 having an insulator 21 in a through hole 20. The through hole 20 has the insulator 21 provided along the inner wall of the through hole 20. The insulator 21 in the illustrated example is a sleeve. In this case, the interior of the insulator 21 becomes the space of the through hole 20. The sleeve is tubular, and more specifically, may be cylindrical. The tubular insulator 21 has a cavity that becomes the through hole 20 in the axial direction of the cylinder.

[0033] The material of the insulator 21 is not particularly limited, but ceramics is preferable. Examples of ceramic materials constituting the insulator 21 include various oxide ceramics and non-oxide ceramics (nitride ceramics, silicate compound ceramics, carbide ceramics, phosphate compounds, etc.). Specific examples of ceramic materials include boron nitride, aluminum nitride, aluminum oxide, yttrium oxide, zirconium oxide, silicon oxide, tin oxide, indium oxide, quartz glass, soda glass, lead glass, borosilicate glass, zirconium nitride, titanium oxide, and silicon carbide.

[0034] The internal space of the through hole 20 may be, for example, a flow path through which the heat transfer gas 22 flows. The heat transfer gas 22 flows along the axial direction of the through hole 20. Even if the insulator 21 is not provided along the inner wall of the through hole 20, it is possible to form a flow path through which the heat transfer gas 22 flows. By providing the through hole 20 with the insulator 21 having low gas permeability, it is possible to easily form a flow path that suppresses leakage of the heat transfer gas 22. The heat transfer gas 22 is not particularly limited, but an inert gas such as helium (He) can be used.

[0035] 4 is a cross-sectional view showing an example of an electrostatic chuck 102 having lift pins 23 in a through hole 20. The through hole 20 in the illustrated example has an insulator 21 provided along the inner wall of the through hole 20. The lift pins 23 move up and down from the base 10 side to the mounting surface 15 side along the axial direction of the through hole 20. The tip ends of the lift pins 23 may protrude above the mounting surface 15. For example, the lift pins 23 may come into contact with the object to be placed.

[0036] In the electrostatic chuck 102 having a flow path through which the heat transfer gas 22 flows or the lifting pins 23, the insulator 21 may protrude above the mounting surface 15 of the mounting member 13 if this does not interfere with the mounting of an object to be mounted. Alternatively, the insulator 21 may have a shape that does not protrude above the mounting surface 15. The sleeve of the insulator 21 may include a rivet sleeve. In the case where the mounting surface 15 has a protruding seal band on the outer periphery thereof, the through hole 20 including the insulator 21 may be disposed within the area surrounded by the seal band.

[0037] The range in which the insulator 21 is disposed on the inner wall of the through hole 20 in the axial direction of the through hole 20 is not particularly limited, and may be within a range from the base 10 to the mounting surface 15, or may be equal to or greater than the distance from the base 10 to the second conductive layer 12, or may be within a range from the base 10 to the second conductive layer 12, or may be only within the range of the base 10. FIG. 5 is a cross-sectional view showing an example of an electrostatic chuck 103 including the insulator 21 on the base 10 side. The insulator 21 in the illustrated example is disposed only below the mounting member 13. That is, the length from the upper surface to the lower surface of the mounting member 13 is greater than the length from the mounting surface 15 to the upper surface 21 a of the insulator 21.

[0038] 6 is a cross-sectional view showing an example of an electrostatic chuck 104 having a porous body 24 in a through hole 20. The through hole 20 in the illustrated example has an insulating porous body 24. This makes it possible to suppress discharge near the mounting surface 15 of the through hole 20. The range in which the porous body 24 is arranged in the axial direction of the through hole 20 is not particularly limited, but may be within the thickness of the mounting member 13, may be equal to or greater than the distance from the mounting surface 15 to the second conductive layer 12, or may be equal to or greater than the distance from the mounting surface 15 to the surface of the base 10.

[0039] 7 is a cross-sectional view showing an example of an electrostatic chuck 105 having a sleeve made of an insulator 21 and a protrusion 25. The protrusion 25 extends along the mounting surface 15 on the outer periphery of the sleeve. The protrusion 25 may be formed continuously in the circumferential direction of the sleeve, or may be formed at multiple locations spaced apart in the circumferential direction of the sleeve. By forming the protrusion 25 on the outer periphery of the insulator 21, fluctuation in the position of the insulator 21 due to thermal stress is reduced, and peeling and the occurrence of voids can be suppressed. The protrusion 25 may be embedded inside the base 10, etc.

[0040] While the present invention has been described above based on preferred embodiments, it is not limited to the above-described embodiments and various modifications are possible without departing from the spirit of the present invention. Modifications include addition, substitution, omission, and other changes to components in each embodiment. Components used in two or more embodiments can also be appropriately combined. For example, a porous body 24 and a protrusion 25 may be used in the insulator 21 for the same through hole 20.

[0041] The present invention will be explained in more detail below by way of experimental examples, but the present invention is not limited to the following experimental examples.

[0042] <Preparation of Electrostatic Chuck> (Example 1) The electrostatic chuck of Example 1 was prepared by the following procedure. Specifically, a 12.5 μm-thick polyimide film (trade name: Kapton (registered trademark), manufactured by DuPont-Toray Co., Ltd.) was used as the resin film. One side of the film was plated with copper (first conductive layer) to a thickness of 12 μm to form an electrode. A curable adhesive sheet was laminated on this electrode. The adhesive sheet used was a mixture of 27 parts by mass of bismaleimide resin, 3 parts by mass of diaminosiloxane, 20 parts by mass of resol phenolic resin, 10 parts by mass of biphenyl epoxy resin, and 240 parts by mass of ethyl acrylate-butyl acrylate-acrylonitrile copolymer, dissolved in an appropriate amount of tetrahydrofuran, formed into a sheet, and then dried in tetrahydrofuran. A polyimide film was then attached and heat-treated to obtain a laminated sheet. The adhesive sheet was cured by heat treatment to form a first adhesive layer. The thickness of the first adhesive layer was 15 μm.

[0043] Furthermore, a circular laminate was cut from the laminate sheet to the diameter shown in Table 1, and another adhesive sheet made of the same material as the adhesive sheet described above was laminated on the side of the laminate opposite to the side on which the polyimide film electrode was formed. The laminate was then attached to an aluminum base (disk-shaped, 300 mm in diameter) (second conductive layer) and bonded by heat treatment. The adhesive sheet used to bond the laminate to the base was cured by heat treatment to form a second adhesive layer. The thickness of the second adhesive layer was 15 μm.

[0044] Next, 100 parts by mass of polysilazane and 200 parts by mass of an inorganic filler made of alumina (average particle diameter: 3 μm) were mixed with butyl acetate as a dilution medium, and the inorganic filler was further uniformly dispersed using an ultrasonic disperser to prepare a coating material.

[0045] Next, the coating material was sprayed onto the entire outer surfaces of the base and the laminate, followed by heating and drying to form an intermediate layer (adhesion layer). The thickness of the intermediate layer on the entire outer surface was 10 μm.

[0046] Next, alumina powder (average particle size: 8 μm) was sprayed onto the entire surface of the intermediate layer by plasma spraying to form a ceramic underlayer having a thickness of 50 μm.

[0047] Next, a mask of a predetermined shape was applied to the surface of the ceramic base layer, and then the above-mentioned alumina powder (average particle size: 8 μm) was sprayed onto the surface of the ceramic base layer to form a ceramic surface layer with a thickness of 15 μm.

[0048] Next, the attracting surface of the ceramic surface layer that attracts the object to be attracted was flat-ground with a diamond grinding wheel to obtain the electrostatic chuck device of Example 1. The end of the electrode that serves as the first conductive layer has a structure in which it is covered with an intermediate layer (adhesion layer), a ceramic base layer, and a ceramic surface layer.

[0049] (Examples 2 to 7, Comparative Example 1) Subsequently, electrostatic chucks of Examples 2 to 7 and Comparative Example 1 were fabricated in the same manner as in Example 1. That is, the electrostatic chucks were fabricated in the same process as in Example 1 except that laminates having diameters shown in Table 1 were used.

[0050] Table 1 shows the dimensions of the electrostatic chuck devices of Examples 1 to 7 and Comparative Example 1. Note that the "diameter of the laminate" in Table 1 is equal to the diameter of the electrode included in the laminate. Furthermore, the "distance between the end of the first conductive layer and the end of the second conductive layer" is a positive value when the end of the second conductive layer protrudes outward beyond the end of the first conductive layer in a plan view with respect to the mounting surface, a negative value when the end of the first conductive layer protrudes outward beyond the end of the second conductive layer, and zero when the positions of the two ends are the same.

[0051] <Evaluation of Electrostatic Chuck> Using the fabricated electrostatic chuck, the discharge inception voltage (kVpp, peak-to-peak voltage at high frequency) and discharge charge quantity (pC) were measured in accordance with JIS C2110-1. That is, the electrode and aluminum base of the electrostatic chuck were connected to an AC stabilized power supply (PCR500LE, manufactured by Kikusui Electronics Co., Ltd.) and ground, respectively. Thereafter, the AC voltage was increased stepwise by 1.0 kVpp (voltage increase rate: 6.0 kVpp / min), and the partial discharge inception voltage and discharge charge quantity were measured when partial discharge was first observed. Note that the voltage application was maintained for 3 minutes at each voltage. The measurement results are shown in Table 1. Note that if partial discharge was observed during the voltage increase, the partial discharge inception voltage and discharge charge quantity at the time when partial discharge was observed were used as the measured values.

[0052]

[0053] As shown in Table 1, the larger the value of the "distance between the end of the first conductive layer and the end of the second conductive layer" was, the higher the discharge initiation voltage was and the smaller the discharge charge amount was.

[0054] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Addition, omission, substitution, and other modifications of the configuration are possible within the scope of the spirit of the present invention. The present invention is not limited by the above description, but is limited only by the scope of the appended claims.

[0055] 10...base, 11...first conductive layer, 11a...peripheral end of first conductive layer, 11b...through hole side end of first conductive layer, 12...second conductive layer, 12a...peripheral end of second conductive layer, 12b...through hole side end of second conductive layer, 13...mounting member, 14...dielectric material, 15...mounting surface, 20...through hole, 21...insulator, 21a...top surface of insulator, 22...heat transfer gas, 23...lifting pin, 24...porous body, 25...protrusion, 100, 101, 102, 103, 104, 105...electrostatic chuck.

Claims

1. An electrostatic chuck comprising: a base; a mounting member having a mounting surface on which an object to be placed is placed; and a first conductive layer provided inside the mounting member, wherein a second conductive layer formed by the base or a second conductive layer provided between the base and the first conductive layer is arranged along the mounting surface together with the first conductive layer, and wherein, in a plan view relative to the mounting surface, the second conductive layer overlaps and includes the first conductive layer, and includes an area where the second conductive layer does not overlap the first conductive layer.

2. An electrostatic chuck as described in claim 1, characterized in that, in a planar view relative to the mounting surface, the region of the second conductive layer overlaps with and includes the outer peripheral end of the first conductive layer, and the outer peripheral end of the second conductive layer includes a region that does not overlap with the first conductive layer.

3. An electrostatic chuck as described in claim 1, characterized in that a through hole is formed extending from the base to the mounting surface, and in a planar view of the mounting surface, a region of the second conductive layer overlaps with and includes an end of the first conductive layer on the through hole side, and the end of the second conductive layer on the through hole side includes a region that does not overlap with the first conductive layer.

4. An electrostatic chuck as described in claim 2, characterized in that, when viewed in a cross-sectional view perpendicular to the mounting surface, the distance between the outer edge of the first conductive layer and the outer edge of the second conductive layer is 0.01 mm or more and 5.0 mm or less.

5. An electrostatic chuck as described in claim 3, characterized in that, when viewed in a cross-sectional view perpendicular to the mounting surface, the distance between the end of the first conductive layer on the through hole side and the end of the second conductive layer on the through hole side is 0.01 mm or more and 5.0 mm or less.

6. An electrostatic chuck according to claim 1, wherein the first conductive layer is an electrode for attracting the object to be placed.

7. The electrostatic chuck according to claim 3, wherein the through-hole is provided with an insulator disposed along the inner wall of the through-hole.

8. The electrostatic chuck according to claim 3, wherein the through-hole is a flow path through which a heat transfer gas flows.

9. An electrostatic chuck according to claim 3, wherein the through-hole is provided with a lifting pin for lifting and lowering an object to be placed.

10. The electrostatic chuck of claim 1, wherein said second conductive layer is connected to a high frequency power source.

11. The electrostatic chuck according to claim 3, wherein the through-hole is provided with an insulating porous body.

12. The electrostatic chuck according to claim 1, wherein the mounting surface includes a thermally sprayed film.

13. The electrostatic chuck according to claim 7, wherein the insulator is a sleeve, and the outer periphery of the sleeve is provided with a protrusion extending along the mounting surface.

14. A semiconductor manufacturing device equipped with the electrostatic chuck according to any one of claims 1 to 13.

15. A plasma processing apparatus equipped with the electrostatic chuck according to any one of claims 1 to 13.

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