Electrostatic chuck device and method for manufacturing electrostatic chuck plate

Abstract

This electrostatic chuck device comprises: an electrostatic chuck plate having a dielectric substrate having a mounting surface on which a sample is mounted, and a suction electrode positioned inside the dielectric substrate; and a base for supporting the electrostatic chuck plate from the opposite side of the mounting surface. The electrostatic chuck plate has a gas hole continuing from the mounting surface to a surface on the opposite side of the mounting surface. A gas hole member for passing sample cooling gas and closing off an end of the gas hole on the mounting surface side is provided in the gas hole. The dielectric substrate and the gas hole member include a shared insulating material and are joined via an insulating layer containing an insulating material.

Description

Electrostatic chuck device and method for manufacturing electrostatic chuck plate

[0001] The present invention relates to an electrostatic chuck device and a method for manufacturing an electrostatic chuck plate. This application claims priority to Japanese Patent Application No. 2024-030395 filed on February 29, 2024, and Japanese Patent Application No. 2024-205394 filed on November 26, 2024, the contents of which are incorporated herein by reference.

[0002] In semiconductor manufacturing processes, electrostatic chucks are used to hold semiconductor wafers in a vacuum environment. The electrostatic chuck device places a plate-like sample, such as a semiconductor wafer, on its mounting surface and generates an electrostatic force between the plate-like sample and an internal electrode to attract and fix the plate-like sample.

[0003] Furthermore, in some electrostatic chuck devices, a cooling gas is supplied between the semiconductor wafer and the mounting surface to cool the semiconductor wafer (see, for example, Patent Document 1). Such cooling gas is supplied through a through-hole provided in the electrostatic chuck device. In the following description, the "through-hole (hole) for supplying gas to the mounting surface" will be referred to as a "gas hole."

[0004] Gas holes may become the origin of discharges that can damage the semiconductor wafer. To suppress such discharges, Patent Document 2 proposes an electrostatic chuck device in which a gas plug (gas hole member) made primarily of silicon carbide is installed in the gas hole. This gas hole member is a conductive porous member that is embedded in the air hole of an insulating base made of ceramics such as aluminum oxide.

[0005] JP 2017-157726 A International Publication No. 2020 / 203680

[0006] However, the inventors' investigations have confirmed that the gas hole member containing silicon carbide as a main component as described above is easily detached from the electrostatic chuck. Therefore, there has been a demand for an electrostatic chuck member in which the gas hole member is less likely to detach from the gas holes.

[0007] The present invention has been made in view of the above circumstances, and has an object to provide an electrostatic chuck device in which a gas hole member installed in a gas hole is unlikely to come off, and a further object of the present invention is to provide a method for manufacturing an electrostatic chuck plate in which a gas hole member installed in a gas hole is unlikely to come off.

[0008] In order to solve the above problems, aspects of the present invention include the following apparatus and manufacturing method.

[0009] [1] An electrostatic chuck device comprising: a dielectric substrate having a mounting surface on which a sample is mounted; an electrostatic chuck plate having an attraction electrode located inside the dielectric substrate; and a base supporting the electrostatic chuck plate from an opposite side of the mounting surface, wherein the electrostatic chuck plate has a gas hole continuing from the mounting surface to an opposite side of the mounting surface, the gas hole having a gas hole member through which a sample-cooling gas passes and which closes an end of the gas hole on the mounting surface side, the dielectric substrate and the gas hole member containing a common insulating material and being bonded to each other via an insulating layer containing the insulating material.

[0010] [2] The electrostatic chuck device according to [1], wherein the dielectric substrate has a through hole that constitutes a part of the gas hole and that is complementarily fitted with the gas hole member, and the diameter of the end of the gas hole member on the mounting surface side is smaller than the diameter of the end of the gas hole member on the base side.

[0011] [3] An electrostatic chuck device comprising: a dielectric substrate having a mounting surface on which a sample is mounted; an electrostatic chuck plate having an attraction electrode located inside the dielectric substrate; and a base supporting the electrostatic chuck plate from the opposite side of the mounting surface, wherein the electrostatic chuck plate has a gas hole continuing from the mounting surface to a surface opposite the mounting surface, the gas hole having a gas hole member through which a sample-cooling gas passes and closing an end of the gas hole on the mounting surface side, the dielectric substrate having a through hole constituting a part of the gas hole and complementary to the gas hole member, and the diameter of the end of the gas hole member on the mounting surface side is smaller than the diameter of the end of the gas hole member on the base side.

[0012] [4] The gas hole member is made of a composite material of an insulating material and a first conductive material, and the volume resistivity of the gas hole member is 1.0×10 １ Ω・cm or more 1.0×10 １０ [4] The electrostatic chuck device according to any one of [1] to [3], wherein the resistance is Ω·cm or less.

[0013] [5] The insulating material is Al ２ O ３ [4] The electrostatic chuck device according to [4], wherein the first conductive material is SiC.

[0014] [6] An electrostatic chuck device according to any one of [1] to [5], wherein the gas hole member has one or more micropores that penetrate in the thickness direction and have a diameter of 0.03 mm or more and 0.15 mm or less.

[0015] [7] The electrostatic chuck device according to any one of [1] to [6], wherein the gas hole member is a porous body.

[0016] [8] An electrostatic chuck device according to any one of [1] to [7], further comprising a support member inserted into the gas hole and supporting the gas hole member, the support member being a porous body.

[0017] [9] The dielectric substrate is made of a composite material of an insulating material and a second conductive material, and the volume resistivity of the dielectric substrate is 1.0×10 １３ Ω・cm or more 1.0×10 １７ [9] The electrostatic chuck device according to any one of [1] to [8], wherein the electrostatic chuck resistance is Ω·cm or less.

[0018]

[10] An electrostatic chuck device according to any one of [1] to [9], wherein the gas holes include a first gas hole that opens on the mounting surface and extends into the interior of the dielectric substrate, a second gas hole that opens on the opposite surface and extends into the interior of the dielectric substrate, and a communication passage that extends in the surface direction of the mounting surface inside the dielectric substrate and connects the first gas hole and the second gas hole.

[0019]

[11] A method for manufacturing an electrostatic chuck plate, comprising: a step of fixing a gas hole member to a gas hole provided in a dielectric substrate having a mounting surface on which a sample is mounted and a built-in chucking electrode, the gas hole member closing an end of the gas hole on the mounting surface side, the dielectric substrate and the gas hole member containing a common insulating material; and a step of applying a bonding paste containing the insulating material to one or both of an inner surface of the gas hole and an outer surface of the gas hole member, the step of inserting the gas hole member into the gas hole, sintering the dielectric substrate and the gas hole member, and bonding the dielectric substrate and the gas hole member via an insulating layer produced by the bonding paste.

[0020] According to the present invention, it is possible to provide an electrostatic chuck device in which a gas hole member installed in a gas hole is unlikely to come off, and a method for manufacturing an electrostatic chuck plate in which a gas hole member installed in a gas hole is unlikely to come off.

[0021] FIG. 1 is a cross-sectional schematic diagram showing an example of an electrostatic chuck device 1A. FIG. 2 is a partially enlarged view of the electrostatic chuck device 1A. FIG. 3 is an explanatory diagram showing an example of an electrostatic chuck device 1B according to a second embodiment of the present invention. FIG. 4 is an explanatory diagram showing an example of an electrostatic chuck device 1C according to a third embodiment of the present invention. FIG. 5 is a schematic diagram showing a modified example of a support member. FIG. 6 is an explanatory diagram of a testing apparatus used in the examples. FIG. 7 is a schematic diagram showing the state of a sintered body when measuring the volume resistivity.

[0022] [First Embodiment] A preferred example of an electrostatic chuck device according to the present embodiment will now be described with reference to the drawings. Note that in all of the following drawings, the dimensions and proportions of the components may be displayed differently as appropriate to make the drawings easier to understand.

[0023] Furthermore, the present embodiment is specifically described to provide a better understanding of the gist of the invention, and does not limit the present invention unless otherwise specified. For example, unless otherwise limited, conditions such as materials, amounts, types, numbers, sizes, shapes, positions, ratios, and temperatures may be changed, added, or omitted as necessary. Furthermore, preferred examples and conditions may be shared or exchanged among the first to third embodiments as long as no problems arise.

[0024] [Electrostatic Chuck Device] Fig. 1 is a schematic cross-sectional view showing a preferred example of an electrostatic chuck device 1A. Fig. 2 is a partially enlarged view of the electrostatic chuck device 1A. As shown in Figs. 1 and 2, the electrostatic chuck device 1A includes an electrostatic chuck plate 2A having a mounting surface 2s on which a sample (wafer W) is mounted, and a base 3 that supports the electrostatic chuck plate 2A from the opposite side (back surface 2p side) of the mounting surface 2s. Note that a focus ring that surrounds the wafer W may be disposed on the outer periphery of the upper surface of the electrostatic chuck plate 2A. Each component will be described below in order.

[0025] <Electrostatic Chuck Plate> The electrostatic chuck plate 2A includes a dielectric substrate 11A and an attraction electrode 13 located inside the dielectric substrate 11A. The electrostatic chuck plate 2A attracts the wafer W onto a mounting surface 2s of the dielectric substrate 11A.

[0026] In the following description, each part of the electrostatic chuck device 1A will be described with the side of the electrostatic chuck plate 2A on which the wafer W is mounted as the upper side and the side facing the base 3 as the lower side. That is, the thickness direction of the electrostatic chuck plate 2A is the up-down direction. Note that the up-down direction here is used merely for the sake of simplicity of description and does not limit the orientation of the electrostatic chuck device 1A during use.

[0027] (Dielectric Substrate) The dielectric substrate 11A has a circular plate shape in a plan view. In this embodiment, "plan view" refers to the thickness direction of the electrostatic chuck device 1A, i.e., the field of view seen from above. The dielectric substrate 11A has a mounting surface 2s on which the wafer W is mounted and a back surface 2p facing the opposite side to the mounting surface 2s. For example, a plurality of protrusions (not shown) are formed at predetermined intervals on the mounting surface 2s. The mounting surface 2s supports the wafer W at the tips of the plurality of protrusions.

[0028] The dielectric substrate 11A is made of a sintered body that has sufficient mechanical strength and is resistant to corrosive gases and their plasma. Ceramics that have sufficient mechanical strength and are resistant to corrosive gases and their plasma are preferably used as the dielectric material that constitutes the dielectric substrate 11A. The dielectric substrate 11A may have a layered structure in which multiple substrates are stacked.

[0029] The ceramics constituting the dielectric substrate 11A can be selected arbitrarily, and for example, aluminum oxide (Al ２ O ３ ), sintered bodies of insulating materials such as aluminum nitride (AlN), and aluminum oxide (Al ２ O ３ ) and a conductive material (second conductive material) silicon carbide (SiC) as a composite sintered body (composite material) ２ O ３ As the insulating material, Al is preferably used. ２ O ３ In particular, from the viewpoints of dielectric properties at high temperatures, high corrosion resistance, plasma resistance, and heat resistance, the material constituting the dielectric substrate 11A is AlN. ２ O ３ -SiC is preferred.

[0030] In this specification, "insulating" means a material having a volume resistivity of 1×10 １３ An "insulating" material has a volume resistivity of 1 x 10 １３ The volume resistivity is 1×10 Ω·cm or more. １４ Ω cm or more, or 1 × 10 １５ Ω cm or more, or 1 × 10 １6 Ω cm or more, or 1 × 10 １7 In this specification, "electrically conductive" means that the volume resistivity is 1×10 １３ A "conductive" material has a volume resistivity of less than 1 x 10 １３ The volume resistivity is less than 1×10 １２ Ω・cm or less or 1×10１１ Ω・cm or less or 1×10 10 Ω・cm or less or 1×10 8 ・ cm or less, 1 x 10 6 Ω・cm or less or 1×10 ３ Ω・cm or less or 1×10 １ It may be Ω·cm or less.

[0031] The dielectric substrate 11A may be made of a compound sintered body (composite material) of an insulating material and a conductive material (second conductive material). In this case, the volume resistivity of the material (composite material) of the dielectric substrate 11A may be 1.0×10 １３ The volume resistivity is preferably 1.0×10 Ω·cm or more, if necessary. １４ Ω cm or more, 1.0 x 10 １５ Ω cm or more, 1.0 x 10 １６ Ω cm or more, 1.0 x 10 １７ The volume resistivity of the material of the dielectric substrate 11A may be 10 Ω·cm or more. １３ If the resistivity is Ω cm or more, application of a voltage to the dielectric substrate 11A generates charges that exert an adsorptive force on the surface of the dielectric substrate 11A, thereby causing the electrostatic chuck device 1A to function as a Coulomb-type electrostatic chuck device.

[0032] The second conductive material is not particularly limited, and may be, for example, silicon carbide (SiC), titanium oxide (TiO ２ ), titanium nitride (TiN), titanium carbide (TiC), carbon material (C), tungsten (W), tungsten carbide (WC), molybdenum (Mo), molybdenum carbide (Mo ２ C), rare earth oxides, rare earth fluorides, carbon black, carbon nanotubes, carbon nanofibers, and multi-layer graphene. Among these, SiC, TiO ２ , TiN, TiC, W, WC, Mo, Mo ２ At least one selected from the group consisting of C and C is preferred, and SiC is more preferred.

[0033] The upper limit of the volume resistivity of the dielectric material (composite material) can be selected arbitrarily, but １７ The upper limit is preferably 10１６ Ω・cm or less, 10 １５ The volume resistivity may be a value obtained by using a direct current three-terminal method at room temperature, for example.

[0034] (Chuck Electrode) The chucking electrode 13 is disposed inside the dielectric substrate 11A. The chucking electrode 13 extends in a plate shape along the mounting surface 2s of the dielectric substrate 11A. When a voltage is applied to the chucking electrode 13, it generates an electrostatic chucking force that holds the wafer W on the mounting surface 2s of the dielectric substrate 11A. The number, shape, and position of the chucking electrodes 13 can be selected arbitrarily. The number of chucking electrodes 13 may be one, or two or more. When there are multiple chucking electrodes, the distances from the mounting surface 2s may be the same or different.

[0035] The chucking electrode 13 is made of a composite material of an insulating material and a conductive material. The insulating material contained in the chucking electrode 13 is not particularly limited, but may be, for example, aluminum oxide (Al ２ O ３ ), aluminum nitride (AlN), silicon nitride (Si ３ N ４ ), yttrium (III) oxide (Y ２ O ３ ), yttrium aluminum garnet (YAG) and SmAlO ３ The conductive material contained in the attraction electrode 13 is preferably at least one selected from the group consisting of molybdenum carbide (Mo ２ It is preferable that the material is at least one selected from the group consisting of molybdenum (Mo), tungsten carbide (WC), tungsten (W), tantalum carbide (TaC), tantalum (Ta), silicon carbide (SiC), carbon black, carbon nanotubes, and carbon nanofibers.

[0036] 2 shows a detailed cross section of the electrostatic chuck device 1A. The electrostatic chuck plate 2A has a first substrate 111, a second substrate 112, and a third substrate 113 as the dielectric substrate 11A, and a first electrode 131 and a second electrode 132 as the attraction electrode 13. The electrostatic chuck plate 2A has the first substrate 111, the first electrode 131, the second substrate 112, the second electrode 132, and the third substrate 113 stacked in this order from the mounting surface 2s side.

[0037] The thickness of the electrostatic chuck plate 2A can be selected arbitrarily, and is preferably 0.5 mm or more and 5 mm or less. When the thickness of the electrostatic chuck plate 2A is 0.5 mm or more, the withstand voltage of the electrostatic chuck plate 2A is high. Furthermore, when the thickness of the electrostatic chuck plate 2A is 5 mm or less, the heat capacity of the electrostatic chuck plate 2A is small, making it easier to maintain a uniform temperature of the plate-shaped sample being the processing target during plasma processing.

[0038] <<Base>> The base 3 supports the electrostatic chuck plate 2A from below. The base 3 has a support surface 3a facing upward and a lower surface 3b facing the opposite side to the support surface 3a. The support surface 3a faces the back surface 2p of the dielectric substrate 11A in the vertical direction. The support surface 3a is in contact with the back surface 2p. That is, the base 3 supports the back surface 2p of the dielectric substrate 11A on the support surface 3a.

[0039] The base 3 is a metal member having a disk shape in a plan view. The material constituting the base 3 is not particularly limited as long as it is a metal having excellent thermal conductivity, electrical conductivity, and workability, or a composite material containing such a metal. Suitable materials for the base 3 include, for example, alloys such as aluminum (Al), copper (Cu), stainless steel (SUS), and titanium (Ti). From the viewpoints of thermal conductivity, electrical conductivity, and workability, the material constituting the base 3 is preferably an aluminum alloy.

[0040] Of the surfaces of the base 3, the surface exposed to plasma is preferably anodized or resin-coated with a polyimide resin. It is more preferable that the entire surface of the base 3 is anodized or resin-coated. By anodizing or resin-coating the base 3, the plasma resistance of the base 3 is improved and abnormal discharge on the surface of the base 3 is suppressed. Therefore, the plasma resistance stability of the base 3 is improved and the occurrence of surface scratches on the base 3 can be prevented.

[0041] The base 3 also functions as an internal electrode for generating plasma. The base 3 is connected to an external high-frequency power source 22 via a matching box (not shown).

[0042] The base 3 is fixed to the electrostatic chuck plate 2A by an adhesive. That is, an adhesive layer 55 that bonds the electrostatic chuck plate 2A and the base 3 to each other is provided between the electrostatic chuck plate 2A and the base 3. The adhesive layer 55 is interposed between the back surface 2p of the electrostatic chuck plate 2A and the support surface 3a of the base 3, and bonds and integrates the electrostatic chuck plate 2A and the base 3. A heater that heats the electrostatic chuck plate 2A may be embedded inside the adhesive layer 55.

[0043] The base 3 is made of a thick, disk-shaped member. The base 3 supports the electrostatic chuck plate 2A from below (the side opposite the dielectric substrate 11A). As described above, the material constituting the base 3 can be selected as needed. Metals with excellent thermal conductivity, electrical conductivity, and processability, composites containing these metals, conductive ceramics, or composite materials of the metals and ceramics (MMC: Metal Matrix Composition) are preferably used. Examples of suitable metals include aluminum, aluminum alloys, copper, copper alloys, and stainless steel. The conductive ceramics are preferably composed of a highly thermally conductive material and a conductive material. The volume ratio of the highly thermally conductive material to the conductive material constituting the conductive ceramics can be selected arbitrarily, but is preferably 10:90 to 90:10. The ratio may be 20:80 to 80:20, 30:70 to 70:30, or 40:60 to 60:40. Examples of highly thermally conductive materials include AlN, SiC, GaN, and SiO. ２ , Al ２ O ３ , SmAlO ３ , Si ３ N ４ , Al(OH) ３ , MgO, Mg(OH) ２ , BN, ZnO, BeO, B ４ The conductive material is preferably at least one selected from the group consisting of C, carbon, aluminum, copper, silver, and gold. ２ , TiN, TiC, W, WC, Mo, MoC, Mo ２ Preferably, the conductive ceramic is at least one selected from the group consisting of C, TaC, TaN, NbC, VC, and C. The conductive ceramic may be composed of, for example, AlN and TiN, AlN and Mo, or AlN, TiN, and Mo. The base 3 of this embodiment may be a water-cooled base having a flow path (not shown) therein for circulating a coolant such as water.

[0044] The adhesive used for the adhesive layer 55 preferably has heat resistance in the temperature range of -20°C to 150°C, and suitable examples include acrylic resins, silicone resins, and epoxy resins.

[0045] The electrostatic chuck plate 2A and the base 3, which are integrated by the adhesive layer 55, are provided with a terminal through-hole 17 that penetrates through a portion of the base 3 and the dielectric substrate 11A in the thickness direction. A power supply terminal 16 for applying a DC voltage to the chucking electrode 13 is inserted into the terminal through-hole 17 and is electrically connected to the chucking electrode 13. An insulating terminal insulator 23 is provided on the outer periphery of the power supply terminal 16. The terminal insulator 23 receives the power supply terminal 16 in a through-hole 15 provided in the terminal insulator 23, thereby insulating the metal base 3 from the power supply terminal 16.

[0046] The power supply terminal 16 is connected to an external power source 21. The power source 21 applies a voltage to the chucking electrode 13. The number, shape, etc. of the power supply terminals 16 are determined depending on the type of the chucking electrode 13, i.e., whether it is a monopolar type or a bipolar type.

[0047] <<Gas Holes and Gas Hole Members>> The electrostatic chuck plate 2A, the base 3, and the adhesive layer 55 are provided with a plurality of gas holes 30A that vertically penetrate these members. Gas hole members 40 are provided at the ends of the gas holes 30A on the mounting surface 2s side. The gas holes 30A are connected to a gas supply device (not shown). The gas holes 30A are provided to supply an arbitrarily selected sample-cooling gas G, such as helium (He), to the mounting surface 2s of the electrostatic chuck plate 2A to cool the wafer W mounted on the mounting surface 2s.

[0048] (Gas Hole) The gas hole 30A has a first through hole 31A that penetrates the electrostatic chuck plate 2A and a second through hole 32 that penetrates the base 3. That is, the first through hole 31A is provided in the electrostatic chuck plate 2A, and the second through hole 32 is provided in the base 3. The first through hole 31A and the second through hole 32 have the same central axis. The first through hole 31A and the second through hole 32 are in communication with each other.

[0049] The first through hole 31A penetrates the dielectric substrate 11A of the electrostatic chuck plate 2A in the thickness direction. Specifically, a through hole 111a provided in the first substrate 111, a through hole 112a provided in the second substrate 112, and a through hole 113a provided in the third substrate 113 are communicated with each other to form the first through hole 31A. In FIG. 2 , the through hole 111a and the through hole 112a have the same size (same diameter), and the through hole 113a has a smaller diameter than the through hole 111a and the through hole 112a.

[0050] The ends of the first electrode 131 and the second electrode 132 are not exposed to the first through-hole 31A. The ends of the first electrode 131 and the second electrode 132 are sealed with an insulating layer 135. The insulating layer 135 can be formed, for example, by applying a commercially available insulating paste to the end of the first electrode 131 and firing it under pressure when forming a laminate by stacking the first substrate 111 and the second substrate 112 with the first electrode 131 sandwiched therebetween.

[0051] The second through hole 32 communicates with the first through hole 31A. A cylindrical insulator 24 may be inserted into the second through hole 32. In Fig. 2, the inner diameter of the insulator 24 is the same as the diameter of the through hole 113a that constitutes part of the first through hole 31A. An upper end of the insulator 24 contacts the back surface 2p of the electrostatic chuck plate 2A (the lower surface of the third substrate 113).

[0052] The outer peripheral surface of the insulator 24 is fixed to the second through hole 32 by, for example, an adhesive. The inside of the insulator 24 functions as a passage for the gas G.

[0053] The insulator 24 can be made of, for example, ceramic. That is, the insulator 24 is made of an insulating material. The insulator 24 has durability against plasma. Examples of ceramics that can be used to make the insulator 24 include AlN, Al ２ O ３ , Si ３ N ４ , ZrO ２ , sialon, and boron nitride (BN).

[0054] (Gas Hole Member) The gas hole member 40 fits into the first through hole 31A and closes the end of the gas hole 30A on the mounting surface 2s side. More specifically, the gas hole member 40 fits into the through holes 111a and 112a and is placed on the third substrate 113. The gas hole member 40 allows the gas G flowing through the gas hole 30A to pass through. The outer diameter of the gas hole member 40 is approximately equal to the inner diameters of the through holes 111a and 112a.

[0055] The gas hole member 40 may have a recess 40x that opens downward (toward the base 3). The recess 40x communicates with the through-hole 113a. The shape and size of the recess 40x can be selected arbitrarily.

[0056] The gas hole member 40 contains the same insulating material (common insulating material) as the insulating material contained in the dielectric substrate 11A. Here, the "same insulating material" refers to the same chemical substance as the material, but the particle size and powder properties may be different.

[0057] That is, the gas hole member 40 is formed by the Al contained in the dielectric substrate 11A. ２ O ３ The insulating material contained in the gas hole member 40 can be selected arbitrarily, and may be, for example, silicon oxide (SiO ２ ), silicon nitride (Si ３ N ４ ), yttrium (III) oxide (Y ２ O ３ ), calcium oxide (CaO), magnesium oxide (MgO), zirconium oxide (ZrO ２ ), yttrium aluminum garnet (YAG) and SmAlO ３ For example, these particles can be suitably used to form the gas hole member 40, and the average particle size thereof can also be selected as desired. The proportion of the insulating material can be selected as desired.

[0058] The gas hole member 40 may also contain a conductive material. The conductive material contained in the gas hole member 40 can be selected arbitrarily, and molybdenum carbide (Mo ２Preferably, the conductive material is at least one selected from the group consisting of molybdenum (Mo), tungsten carbide (WC), tungsten (W), tantalum carbide (TaC), tantalum (Ta), SiC, carbon black, carbon nanotubes, and carbon nanofibers. For example, these particles can be suitably used to form the gas hole member 40, and their average particle diameter can also be selected as desired. The proportion of the conductive material can be selected as desired. For example, the conductive material may be 10 to 30 mass %, 15 to 25 mass %, or 15 to 20 mass % of the total mass of the gas hole member 40, but is not limited to these.

[0059] The shape of the gas hole member 40 is complementary to the shape of the first through hole 31 A. For example, if the first through hole 31 A is circular in plan view and has a uniform cross-sectional shape extending in the vertical direction, the gas hole member 40 will have a cylindrical shape extending in the vertical direction.

[0060] 2, the height of the gas hole member 40 is shorter than the vertical length of the first through hole 31A and the gas hole member 40 is placed on the third substrate 113. However, this is not limited to this. For example, if the through holes 111a, 112a, and 113a constituting the first through hole 31A are the same size and the inner surface of the first through hole 31A is a continuously curved cylindrical surface, the height of the gas hole member 40 may be the same as the vertical length of the first through hole 31A. That is, the gas hole member 40 may be cylindrical and have the same thickness as the electrostatic chuck plate 2A. In this case, the upper end of the gas hole member 40 is aligned with the upper end of the first through hole 31A and is at the same height as the mounting surface 2s.

[0061] The gas hole member 40 will be described in detail later.

[0062] (Insulating Layer) The insulating layer 49 is formed between the gas hole member 40 and the dielectric substrate 11A. The insulating layer 49 is provided in contact with either or both of the side surface 40a and the bottom surface 40b of the gas hole member 40, and fills the space between the gas hole member 40 and the first through hole 31A.

[0063] The insulating layer 49 contains the same insulating material as the insulating material contained in the dielectric substrate 11A and the gas hole member 40. Thus, by heating the entire surface during the manufacture of the electrostatic chuck plate 2A, the insulating material (e.g., Al ２ O ３ ) and the same insulating material contained in the dielectric substrate 11A are sintered and bonded together. Also, the insulating material contained in the insulating layer 49 and the same insulating material contained in the gas hole member 40 are sintered and bonded together. As a result, the insulating layer 49 is bonded to the dielectric substrate 11A and the gas hole member 40, and the gas hole member 40 can be firmly fixed to the gas hole 30A.

[0064] In the electrostatic chuck plate 2A of this embodiment, the gas hole member 40 is firmly fixed to the gas holes 30A. Therefore, even if the electrostatic chuck device 1A of this embodiment is exposed to plasma and the multiple protrusions formed on the mounting surface 2s are worn and roughened, i.e., even if the protrusions on the mounting surface 2s deteriorate, the multiple protrusions can be easily reformed. That is, because the gas hole member 40 of this embodiment is firmly fixed to the gas holes 30A, the multiple protrusions on the mounting surface 2s worn by plasma processing can be reformed by surface grinding or the like without detaching or replacing the gas hole member 40.

[0065] Furthermore, by filling the gap between the dielectric substrate 11A and the gas hole member 40 with the insulating layer 49, abnormal discharge around the gas holes can be easily suppressed when the electrostatic chuck device 1A is exposed to a plasma environment.

[0066] The insulating layer 49 can be formed by any method, for example, by applying a bonding agent (bonding paste) containing an insulating material to one or both of the side surface 40a and the bottom surface 40b of the gas hole member 40 when fitting the gas hole member 40 into the gas hole 30A, and then fitting and firing the gas hole member 40. The insulating layer 49 can also be formed by applying a bonding agent to the inner side surface and / or inner bottom surface of the gas hole 30A, inserting the gas hole member 40 into the gas hole, and sintering the gas hole member 40.

[0067] The bonding paste may contain, for example, a particulate insulating material, a solvent, and a binder. Alternatively, the bonding paste may contain a particulate insulating material and a commercially available solvent for screen printing. The ratio of these components can be selected arbitrarily.

[0068] As the solvent, it is preferable to use a high-boiling organic solvent such as a diol such as hexylene glycol or propylene glycol, or a terpene such as terpineol.

[0069] As the binder, a cellulose-based resin such as ethyl cellulose, an acrylic-based resin such as polymethyl methacrylate, or a vinyl-based resin such as polyvinyl butyral can be used.

[0070] The bonding paste may further contain, as appropriate, commonly used additives such as a leveling agent, a chelating agent, a surfactant, and a thickener.

[0071] The leveling agent may include water, ethylene glycol, polyethylene glycol, and glycerin.

[0072] Chelating agents include acetylacetone, benzylacetone, and acetic acid.

[0073] The surfactant may be polyethylene glycol or the like.

[0074] Examples of thickeners include methyl cellulose and ethyl cellulose.

[0075] (Details of Gas Hole Member) As described above, the gas hole member 40 allows the gas G flowing through the gas holes 30A to pass through. The structure of the gas hole member 40 that allows the gas G to pass through is not particularly limited.

[0076] For example, the gas hole member 40 may be a porous body. When the gas hole member 40 is a porous body, the pores in the porous body are connected to each other and are continuous in the vertical direction of the gas hole member 40, thereby forming a flow path for the gas G in the gas hole member 40.

[0077] The pore diameter of the porous body is not particularly limited as long as it can sufficiently supply gas G to the mounting surface 2s and suppress abnormal discharge. The pore diameter of the porous body can be selected arbitrarily, and may be, for example, 30 μm or more and 150 μm or less, 45 μm or more and 125 μm or less, or 60 μm or more and 110 μm or less. If the pore diameter of the gas hole member 40 is too small, it may not be possible to sufficiently supply gas G to the mounting surface 2s. If the pore diameter is too large, the potential change near the upper end of the first through hole 31A may be large, and the generated electric field may also be large, making it difficult to suppress abnormal discharge.

[0078] The porosity of the porous body is not particularly limited as long as it can supply sufficient gas G to the mounting surface 2s, and may be, for example, 30% or more and 70% or less, 40% or more and 60% or less, or 45% or more and 55% or less.

[0079] Here, "porosity" refers to the ratio of the total volume of pores to a given unit volume of the porous body. The porosity may be a value determined from the ratio of the true density of the material forming the porous body to the apparent density of the porous body, or may be determined by actually measuring the volume of pores per unit volume. The higher the porosity of a porous body, the more pores there are, and the easier it is for gas G to flow out.

[0080] The gas hole member 40 may have one or more micropores penetrating through it in the thickness direction. When the gas hole member 40 has micropores, the diameter of the micropores is not particularly limited as long as the gas G can be sufficiently supplied to the mounting surface 2s. For example, the diameter of the micropores may be 0.02 mm or more and 0.15 mm or less. It may also be 0.03 mm or more and 0.15 mm or less, 0.05 mm or more and 0.13 mm or less, or 0.08 mm or more and 0.11 mm or less.

[0081] The shape of the micropores is not particularly limited as long as the gas G can pass through them, and may be rectangular, cubic, or cylindrical.

[0082] The number of micropores may be adjusted appropriately to a number that satisfies both gas permeability and abnormal discharge suppression. The micropores can be formed by various methods. For example, micropores may be formed in a molded body that does not have micropores by laser processing or mechanical processing. The gas hole member 40 may also be a porous body having one or more micropores that penetrate through the body in the thickness direction.

[0083] The gas hole member 40 preferably contains an insulating material, more preferably contains an insulating material and a conductive material, and even more preferably is made of a composite material of an insulating material and a conductive material (first conductive material). That is, it is particularly preferable that the gas hole member 40 is made of the composite material. In this case, the volume resistivity of the material of the gas hole member 40 is 1.0×10 １ Ω・cm or more 1.0×10 １０ It is preferably Ω cm or less, and 1.0 × 10 ２ Ω・cm or more 1.0×10 １０ It is more preferable that the resistance is Ω cm or less, and 1.0 × 10 ３ Ω・cm or more 1.0×10 １０ It is more preferable that the volume resistivity of the material of the gas hole member 40 is 1.0×10 ４ Ω・cm or more 1.0×10 ９ It may be Ω cm or less, and may be 1.0 × 10 ５ Ω・cm or more 1.0×10 ８ It may be Ω cm or less, and may be 1.0 × 10 ６ Ω・cm or more 1.0×10 ７ It may be Ω·cm or less.

[0084] The first conductive material is not particularly limited as long as it can be used as a gas hole member. For example, molybdenum carbide (Mo ２ At least one material selected from the group consisting of molybdenum (Mo), tungsten carbide (WC), tungsten (W), tantalum carbide (TaC), tantalum (Ta), SiC, carbon black, carbon nanotubes, and carbon nanofibers can be used. The first conductive material may be the same as or different from the second conductive material. SiC is more preferred as the first conductive material.

[0085] The volume resistivity of the gas hole member 40 is 1.0×10 ３ If the resistivity is less than Ω cm, electricity will easily flow, which may increase heat generation near the first through hole 31A and reduce the plasma resistance of the gas hole member 40. ３ It is more preferable that the volume resistivity of the gas hole member 40 is 1.0×10 １０ If the electrical resistance exceeds Ω·cm, it is not preferable because there is a possibility that abnormal discharge occurring around the first through-hole 31A cannot be sufficiently suppressed.

[0086] The gas hole member 40 is made of an insulating material such as Al. ２ O ３ , a composite material in which the first conductive material is SiC, i.e., Al ２ O ３ It is preferable to use SiC. ２ O ３ The gas hole member 40 made of -SiC can suppress abnormal discharge and has excellent plasma resistance. Furthermore, because such a gas hole member 40 has excellent strength, it can suppress breakage when reforming the multiple protrusions on the mounting surface 2s by surface grinding or the like.

[0087] Conventional gas hole members have generally been made of insulating materials, but with the recent trend toward higher power semiconductor manufacturing equipment, it has become difficult to suppress the occurrence of abnormal discharge using insulating gas hole members.

[0088] Therefore, the present inventors conducted various studies using simulations and surprisingly found that, when the side portions of the gas hole member are conductive, an equipotential is maintained from the top end to the bottom end of the gas hole member even when the electrostatic chuck device is exposed to plasma, that is, the gas hole member does not become a starting point for abnormal discharge. ３ Ω・cm or more 1.0×10 １０ It was conceived that it would be preferable to use a material with a resistivity of Ω·cm or less.

[0089] The method for measuring the volume resistivity of the gas hole member 40 is not particularly limited, but for example, it can be measured by a direct current three-terminal method.

[0090] The material of the gas hole member 40 is preferably a composite of an insulating material and a conductive material. The volume resistivity of such a composite can be adjusted to a desired value by adjusting the types of insulating material and conductive material and the mixing ratio of the insulating material and the conductive material.

[0091] Since the material of the gas hole member 40 is a composite material of an insulating material and a conductive material, it is easy to adjust the volume resistivity of the gas hole member 40 within a desired range. Therefore, it is possible to easily obtain a gas hole member 40 that can suppress abnormal discharge and has excellent plasma resistance.

[0092] The size of the gas hole member 40 is not particularly limited as long as it can be provided in the first through-hole 31A. For example, the diameter may be 0.5 mm to 2.5 mm and the thickness may be 1 mm to 10 mm. The shape of the upper surface of the gas hole member 40 in plan view can be selected arbitrarily and may be, for example, circular.

[0093] As an example, the gas hole member 40 can be manufactured by the following method.

[0094] First, the above-mentioned insulating material and conductive material are mixed with a binder, a dispersant, a solvent, etc. as appropriate to prepare a slurry.

[0095] Next, a pore-opening agent is further added to the resulting slurry, if necessary.

[0096] Next, the slurry containing the pore-opening agent is placed in a mold of the desired shape and fired to obtain the gas hole member 40. The pore-opening agents come into contact with each other as the slurry dries, and then disappear during firing. As a result, in the resulting gas hole member 40, continuous pores are formed in the vertical direction of the gas hole member 40 at the positions where the pore-opening agent was present. The amount of pore-opening agent is the amount that will form pores that communicate with each other in the resulting gas hole member 40. It is recommended that the specific amount used be confirmed in advance through a preliminary experiment.

[0097] Alternatively, the obtained slurry can be impregnated into a mold of a porous material such as urethane sponge, temporarily dried to remove excess slurry, and then fired to obtain the gas hole member 40.

[0098] The mold of the porous member disappears during firing, and as a result, continuous pores are formed in the vertical direction of the gas hole member 40 at the positions where the mold agent of the porous member was present.

[0099] Alternatively, a photosensitive material such as a photocurable resin can be further added to the slurry, and the resulting photosensitive material-containing slurry can be molded into a desired shape using a stereolithography device to form a temporary molded body, which can then be fired to obtain the gas hole member 40. The photosensitive material disappears during firing. By forming a plurality of through holes in the temporary molded body during stereolithography, micropores that penetrate the gas hole member 40 can be formed in the resulting gas hole member 40 at positions corresponding to the through holes.

[0100] The through-holes formed by stereolithography may pass straight through the provisional molded body, or may be curved or bent inside the provisional molded body.

[0101] Furthermore, a pore-forming agent may also be added to the slurry containing the photosensitive material to form pores in the resulting gas hole member.

[0102] The gas hole member 40 thus manufactured may have micropores formed therein by laser processing or machining.

[0103] Alternatively, the above slurry may be molded and fired without using a pore-opening agent, a porous member mold, or a photosensitive material, and the resulting sintered body may be processed by laser processing or machining to form micropores, thereby forming the gas hole member 40.

[0104] The obtained gas hole member 40 can be fixed in the gas hole by applying a bonding agent to the side surface 40a and bottom surface 40b, pressing it into the gas hole (through hole 111a, through hole 112a) provided in the dielectric substrate 11A, and firing it.

[0105] The recesses 40x may be formed by machining the bottom surface of the gas hole member 40. The recesses 40x may be formed before the gas hole member 40 is press-fitted into the gas hole, or may be formed after the gas hole member 40 is press-fitted into the gas hole.

[0106] When forming the recesses 40x after press-fitting the gas hole member 40 into the gas hole, there is a concern that the gas hole member 40 may become detached from the gas hole due to the pressure applied during processing. However, in this embodiment, the gas hole member 40 is bonded to the dielectric substrate 11A via the insulating layer 49 and is firmly fixed within the gas hole. Therefore, even when processing to form the recesses 40x as described above is performed, the gas hole member 40 is less likely to become detached, and the recesses 40x can be formed appropriately.

[0107] During sintering, the insulating material contained in the bonding agent may diffuse into the dielectric substrate 11A and the gas hole member 40, making it difficult to identify the insulating layer 49 or reducing the thickness of the insulating layer 49 to a value below the detection limit. In such a case, the insulating layer 49 is substantially absent, resulting in an electrostatic chuck plate 2A in which the dielectric substrate 11A and the gas hole member 40 are bonded to each other. Even with such an electrostatic chuck plate 2A, the effects of the present invention can be achieved.

[0108] [Method of Manufacturing Electrostatic Chuck Plate] The electrostatic chuck plate 2A (electrostatic chuck device 1A) as described above can be manufactured by, for example, the following method. The method of manufacturing the electrostatic chuck plate 2A includes a step of fixing a gas hole member 40 to a gas hole 30A provided in a dielectric substrate 11A having a mounting surface 2s on which a sample is mounted and a built-in attraction electrode 13, the gas hole member 40 closing the end of the gas hole 30A on the mounting surface side. The fixing step can be a method including the following steps (1) to (3): (1) a step of applying a bonding paste containing an insulating material to either or both of the side surface of the gas hole member 40 and the inner surface of the gas hole 30A; (2) a step of inserting the gas hole member 40 into the gas hole 30A; and (3) a step of sintering the dielectric substrate 11A and the gas hole member 40 and bonding the dielectric substrate 11A and the gas hole member 40 via an insulating layer 49 formed from the bonding paste.

[0109] As described above, the dielectric substrate 11A and the gas hole member 40 contain a common insulating material. The same insulating material is also contained in the bonding paste. The bonding paste may be one of those described above. In step (2) above, the gas hole member 40 may be inserted into the gas hole 30A from the mounting surface side or the opposite side, as needed. Furthermore, steps (1) and (2) may be performed during the process of laminating multiple substrates and one or more electrodes to obtain the dielectric substrate 11A, as needed. For example, the process may include a step of providing another chucking electrode and / or laminating another dielectric substrate on the side opposite the mounting surface 2s of the dielectric substrate to which the gas hole member is fixed. This may be pressurized and fired as needed. Holes or grooves may be formed in advance at predetermined locations in the other chucking electrode.

[0110] The sintering temperature in the step (3) can be, for example, 1400 to 1900°C. The temperature may be 1500 to 1800°C or 1600 to 1700°C.

[0111] The electrostatic chuck plate thus obtained is joined to the base 3, thereby manufacturing an electrostatic chuck device.

[0112] In the electrostatic chuck device 1A configured as described above, the gas hole member installed in the gas hole is unlikely to come off.

[0113] Furthermore, in the method for manufacturing an electrostatic chuck plate as described above, it is possible to easily manufacture an electrostatic chuck plate in which the gas hole members installed in the gas holes are not easily detached.

[0114] 3 is an explanatory diagram of an electrostatic chuck device 1B according to a second embodiment of the present invention, and corresponds to FIG. 2 of the first embodiment. In this embodiment, components common to those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0115] The electrostatic chuck device 1B shown in FIG. 3 includes an electrostatic chuck plate 2B having a mounting surface 2s on which a sample (wafer W) is mounted, and a base 3 that supports the electrostatic chuck plate 2B from the opposite side of the mounting surface 2s.

[0116] The electrostatic chuck plate 2B includes a dielectric substrate 11B and an attraction electrode 13 located inside the dielectric substrate 11B. The electrostatic chuck plate 2B attracts the wafer W onto a mounting surface 2s of the dielectric substrate 11B.

[0117] The dielectric substrate 11B has a first substrate 115, a second substrate 112, and a third substrate 113. The electrostatic chuck plate 2B has the first substrate 115, a first electrode 131, the second substrate 112, the second electrode 132, and the third substrate 113 stacked in this order from the mounting surface 2s side. For example, a plurality of protrusions (not shown) are formed at predetermined intervals on the surface (mounting surface 2s) of the first substrate 115. The mounting surface 2s supports the wafer W at the tips of the plurality of protrusions.

[0118] The dielectric substrate 11B has a first through-hole 31B penetrating through it in the thickness direction. The first through-hole 31B and the second through-hole 32 of the base 3 are in communication with each other to form a gas hole 30B. The first through-hole 31B and the second through-hole 32 have the same central axis.

[0119] Gas hole 30B is formed by communication between through hole 115a provided in first substrate 115, through hole 112a provided in second substrate 112, and through hole 113a provided in third substrate 113. The central axes of through holes 115a, 112a, and 113a are aligned with one another. These through holes 115a, 112a, and 113a each constitute a part of gas hole 30B.

[0120] In FIG. 3, the through-hole 115a and the through-hole 113a have the same size, and the through-hole 112a has a larger diameter than the through-holes 115a and 113a.

[0121] The gas hole member 41 complementarily fits into the first through hole 31B and closes the end of the gas hole 30B on the mounting surface 2s side. Specifically, the gas hole member 41 fits into the through hole 115a and the through hole 112a and is placed on the third substrate 113. The gas hole member 41 has a convex shape formed by connecting a cylindrical first portion 411 that fits into the through hole 115a and a cylindrical second portion 412 that is larger in diameter than the first portion 411 and is continuous with the first portion 411. In other words, the diameter of the end of the gas hole member 41 on the mounting surface 2s side (the diameter of the first portion 411) is smaller than the diameter of the end of the gas hole member 41 on the base 3 side (the diameter of the second portion 412).

[0122] The gas hole member 41 may have a recess 41x that opens downward (toward the base 3). The recess 41x communicates with the through-hole 113a.

[0123] The gas hole member 41 is brought into contact with the lower surface 115x of the first substrate 115 at the upper surface 412a of the second portion 412. As a result, in the electrostatic chuck device 1B configured as described above, the gas hole member 41 installed in the gas hole 30B is less likely to come off.

[0124] 4 is an explanatory diagram of an electrostatic chuck device 1C according to a third embodiment of the present invention, and corresponds to FIG. 2 of the first embodiment. The electrostatic chuck device 1C shown in FIG. 4 includes an electrostatic chuck plate 2C having a mounting surface 2s on which a sample (wafer W) is mounted, and a base 3 that supports the electrostatic chuck plate 2C from the side opposite to the mounting surface 2s.

[0125] The dielectric substrate 11C has a first substrate 111, a second substrate 112, and a third substrate 116. The electrostatic chuck plate 2C has the first substrate 111, a first electrode 131, the second substrate 112, a second electrode 132, and the third substrate 116 stacked in this order from the mounting surface 2s side.

[0126] The dielectric substrate 11C has gas holes 30C that continue from the mounting surface 2s to the surface opposite the mounting surface 2s (rear surface 2p). The gas holes 31C that penetrate the first substrate 111 and the second substrate 112 and the second gas holes 312 formed in the third substrate 116 communicate with each other to form the gas holes 30C. The gas holes 30C and the second through holes 32 of the base 3 also communicate with each other.

[0127] The gas hole 30C has a first gas hole 311, a second gas hole 312, and a communication passage 313 connecting these. In the gas hole 30C, these are connected to each other to form a gas flow path that continues from the mounting surface 2s to the back surface 2p.

[0128] The first gas holes 311 of the dielectric substrate 11C are open to the mounting surface 2s and extend into the dielectric substrate 11C along the thickness direction of the dielectric substrate 11C. The first gas holes 311 are formed by communication between a through hole 111a provided in the first substrate 111 and a through hole 112a provided in the second substrate 112. The central axes of the through holes 111a and 112a are aligned with each other.

[0129] The second gas holes 312 of the dielectric substrate 11C are opened to the rear surface 2p and extend into the dielectric substrate 11C along the thickness direction of the dielectric substrate 11C.

[0130] The communication path 313 of the dielectric substrate 11C extends in the surface direction of the mounting surface 2s inside the dielectric substrate 11C and connects the first gas hole 311 and the second gas hole 312. The communication path 313 is a space surrounded by a groove 313x that is provided on the surface of the third substrate 116 facing the mounting surface 2s and connects the first gas hole 311 and the second gas hole 312, and the surface of the second substrate 112 facing the base 3.

[0131] In this embodiment, the communicating path 313 is formed using a groove provided in the third substrate 116, but this is not limiting. The communicating path may also be a space surrounded by a groove provided in the surface of the second substrate 112 facing the base and the surface of the third substrate 116 facing the mounting surface 2s. In this case, the first gas hole 311 may be connected to the communicating path at a side of the through-hole 112a rather than at the lower end thereof. The second gas hole 312 may be a hole penetrating the third substrate 116, and may be connected to this communicating path at the upper end of the hole. The communicating path 313 may have a constant depth, or may have an inclined side surface and / or a curved surface as shown in FIG. 4.

[0132] The end of the gas hole 31C on the mounting surface 2s side is closed by a gas hole member 42. The gas hole member 42 allows gas flowing through the gas hole 30C to pass through, similar to the above-mentioned gas hole members 40 and 41. The gas hole member 42 may be a porous body, and may have one or more fine holes penetrating in the thickness direction.

[0133] The side surface of the gas hole member 42 is bonded to the inner surface of the gas hole 31C (first gas hole 311) via an insulating layer 49. In Fig. 4, the cross-sectional view shows that the height of the top surface of the gas hole member 42 and the bottom surface (valley portion) from which the protrusion 211 protrudes are the same, that is, the top surface of the gas hole member 42 is located lower than the mounting surface 2s, but this configuration is not limiting. For example, if necessary, the top surface of the gas hole member 42 may be located at a height between the bottom surface and the mounting surface 2s, or may be located at the same height as the mounting surface 2s.

[0134] A support member 45A is inserted below the gas hole member 42 in the first gas hole 311. In Fig. 4, the support member 45A is disposed across the through hole 111a and the through hole 112a of the first gas hole 311.

[0135] The support member 45A has an upper surface 45x in contact with the lower surface 42x of the gas hole member 42, and supports the gas hole member 42.

[0136] The support member 45A is made of alumina (Al ２ O ３The support member 45A is preferably an open-pore ceramic member such as silicon carbide (SiC), and particularly preferably an alumina porous member. Such a support member 45A allows the gas flowing through the gas holes 30C to pass through. Furthermore, since the support member 45A is a ceramic member, the pores are less likely to be clogged, even during sintering to bond the gas hole member 42 to the dielectric substrate 11C, making it easier to maintain the desired functionality.

[0137] A part or all of the support member 45A may be inserted or press-fitted into the first gas hole 311, or may be joined to the inner surface of the first gas hole 311 via an insulating layer, similar to the gas hole member 42. Furthermore, the upper surface 45x of the support member 45A and the lower surface 42x of the gas hole member 42 may be joined together as long as this does not impede the flow of gas through the gas hole 30C.

[0138] 4, the support member 45A is not inserted into the communicating passage 313, but the support member 45A may be inserted into the communicating passage 313 as long as it does not obstruct the flow of gas through the gas hole 30C. For example, the lower end 45y of the support member 45A may be in contact with the inner surface of the groove 313x. The support member 45A may have any shape, such as a cylindrical shape.

[0139] 5 is a schematic diagram showing a modified example of the support member. For example, as shown in FIG. 5, a support member 45B may be configured such that the lower end is machined to provide holes 45h through which gas flowing in the communication passage 313 passes, and foot portions 45f formed at the same time are in contact with the inner surface of the groove 313x.

[0140] 5 may be used as a gas hole member. That is, the gas hole member may have a main body portion of the gas hole member that allows gas to pass through and a foot portion that supports the main body portion. In this case, the support member 45B (gas hole member) may have a size that extends from the top end of the first gas hole 311 to the bottom of the communication passage 313.

[0141] As a result of repeated use in a plasma environment, the protrusions 211 on the mounting surface 2s of an electrostatic chuck device may wear out, making it difficult for the device to perform its desired function. In recent years, electrostatic chuck devices having such worn protrusions 211 are sometimes reprocessed to re-form the multiple protrusions 211 on the mounting surface 2s. In such processing, the mounting surface 2s is subjected to mechanical processing such as blasting, but in conventional electrostatic chuck devices, there is a concern that the gas hole member may become dislodged due to the impact caused by this processing.

[0142] To address such concerns, in the electrostatic chuck device 1C of the present embodiment, the gas hole member 42 is bonded to the dielectric substrate 11C, so that the gas hole member 42 installed in the gas hole 30C is less likely to come off. Therefore, the protrusion 211 can be suitably re-machined.

[0143] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to these examples. The shapes and combinations of the components shown in the above examples are merely examples, and various modifications can be made based on design requirements, etc., without departing from the spirit of the present invention.

[0144] The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[0145] [Example 1] [Preparation of sintered body for gas hole member] As starting materials, silicon carbide (SiC) particles having an average particle size of 0.03 μm and aluminum oxide (Al 2 O 3 ) having an average particle size of 0.1 μm were used. ２ O ３ ) particles were used. SiC particles and Al ２ O ３ The SiC particles were weighed out so that they accounted for 18 mass % of the total amount of the particles.

[0146] Next, a dispersion medium was prepared by dissolving a polycarboxylic acid-based dispersant in distilled water, and the weighed particles were added to the obtained dispersion medium. The obtained dispersion was dispersed using an ultrasonic dispersion device, and then crushed and mixed using a two-flow particle collision type crushing and mixing device to obtain a mixture of SiC particles and Al particles. ２ O ３ A particle-containing slurry was obtained.

[0147] The resulting slurry was impregnated into a urethane sponge and dried. The resulting dried body was then fired at 1800°C for 48 hours in an Ar atmosphere to obtain the sintered body of Example 1. The resulting sintered body was a porous body using the urethane sponge as a mold.

[0148] [Preparation of bonding paste] Al having an average particle size of 0.1 μm ２ O ３ The particles were dispersed in a solvent for screen printing to prepare a bonding paste.

[0149] [Evaluation] (1. Adhesion strength) The sintered body for the gas hole member was machined to obtain a cylindrical test piece having a diameter of 2 mm and a thickness of 1 mm. ２ O ３ -SiC sintered body (mass ratio Al ２ O ３ A bonding paste was applied to the side of the test piece, which was then pressed into a through-hole in a dielectric substrate and dried at 150° C. for 3 hours.

[0150] The dried body was placed in a graphite mold and subjected to pressure sintering. Specifically, the dried body was heated to 1100°C under a vacuum atmosphere at a pressing pressure of 5 MPa, and then heated to 1800°C under an argon atmosphere at a pressing pressure of 40 MPa, to obtain a model green body of Example 1.

[0151] In the model green body obtained by pressure sintering, the dielectric substrate corresponds to the dielectric substrate in the electrostatic chuck plate, the through holes provided in the dielectric substrate correspond to the gas holes in the electrostatic chuck plate, and the test piece corresponds to the gas hole member in the electrostatic chuck plate.

[0152] The adhesive strength of the test piece A2 in the model molded body A was measured using a test device 200 shown in FIG.

[0153] The model molded body A was placed on a pedestal 220, and a pressure terminal 210 having a diameter of 1.1 mm was brought into contact with the test piece A2 of the model molded body A, and a load was gradually applied to the test piece A2. The load at which the test piece A2 was detached from the dielectric substrate A1 was defined as the adhesive strength.

[0154] As a result of the evaluation, the dielectric substrate was broken at a load of 400 N, and the test could not be continued at any load greater than this. From the results of the adhesive strength test, it was confirmed that in the model molded body of Example 1, the test piece corresponding to the gas hole member did not detach from the through hole (gas hole) even when a load of 400 N was applied.

[0155] (2. Volume Resistivity) The sintered body for the gas hole member was machined to obtain a cylindrical test piece having a diameter of 28 mm and a thickness of 1 mm. The volume resistivity (Ω cm) of the obtained test piece was measured by a direct current three-terminal method.

[0156] (Equipment used) Screen printing machine: Model MEC-2400, manufactured by Mitani Micronics Co., Ltd. Resistivity measuring device: manufactured by Nishiyama Manufacturing Co., Ltd. Digital ultra-high resistance / microcurrent meter (Model 5450, manufactured by ADC Corporation)

[0157] (Measurement conditions) Measurement temperature: room temperature (24°C) Measurement atmosphere: air (flow rate 200 ml / min) Applied voltage: 500 V

[0158] (Measurement Method) Using a screen printer, silver paste (US-202A, manufactured by Daiken Chemical Manufacturing and Sales Co., Ltd.) was printed on the upper and lower surfaces of the sintered body, and then dried in air at 150° C. for 12 hours to form a main electrode 110, a guard electrode 120, and a counter electrode 130 as shown in FIG. 7.

[0159] At this time, the diameter of the main electrode 110 was 1.45 cm, and the inner diameter of the guard electrode 120 was 1.60 cm.

[0160] A DC voltage was applied to the sintered body 100 having the main electrode 110, guard electrode 120, and counter electrode 130 formed thereon, and the current after charging for 1 minute was measured to determine the volume resistance (Rv) of the sintered body. Next, the volume resistivity (ρv) was calculated using the thickness of the sintered body and the area of ​​the electrode according to the following formula (1): ρv = S / t × Rv = S / t × V / I (1) (S: effective area of ​​the electrode (cm ２ ), t: thickness of sintered body (cm), Rv: volume resistance (Ω), V: DC voltage (V), I: current (A)

[0161] As a result of the evaluation, the volume resistivity of the test piece was 1.1 × 10 ５ The value was Ω·cm.

[0162] (3. Discharge Test) The sintered body for the gas hole member was machined to obtain a gas hole member for the electrostatic chuck device shown in FIG. 1. An insulating paste (joining paste) was applied to the side surface of the gas hole member, and the gas hole member was press-fitted into the first through hole 31A of the dielectric substrate 11A. The dielectric substrate with the press-fitted gas hole member was dried at 150°C for 3 hours and heated at 1800°C under a press pressure of 40 MPa to integrally bond the dielectric substrate and the gas hole member. The electrostatic chuck device of Example 1 was obtained using the obtained electrostatic chuck plate.

[0163] The electrostatic chuck device of Example 1 was installed in a vacuum chamber of a semiconductor manufacturing apparatus, and a semiconductor wafer (wafer) was attracted to the mounting surface. In this state, the semiconductor manufacturing apparatus was operated, and plasma was applied to the wafer.

[0164] As a result, no discharge marks or the like were found on the wafer. That is, no abnormal discharge was observed in the electrostatic chuck device of Example 1, and it was confirmed that discharge was suppressed. Furthermore, the gas hole member did not detach from the through hole from the manufacturing process of the electrostatic chuck device until the discharge test was completed.

[0165] [Example 2] [Production of sintered body for gas hole member] The slurry obtained in Example 1 was spray-dried using a spray dryer to obtain a sintered body of SiC and Al. ２ O ３ The mixed particles were subjected to uniaxial press molding at a pressure of 8 MPa to form a molded body having a diameter of 320 mm and a thickness of 15 mm.

[0166] The resulting molded body was then heat-treated in a nitrogen atmosphere by raising the temperature to 385°C at a temperature increase rate of 0.5°C / min without applying pressure, to remove moisture and dispersant (impurities) contained in the molded body.

[0167] The obtained compact was set in a graphite mold and subjected to pressure sintering. Specifically, the compact was heated to 1100°C under a vacuum atmosphere at a pressing pressure of 5 MPa, and then heated to 1800°C under an argon atmosphere at a pressing pressure of 40 MPa, thereby obtaining a sintered compact of Example 2.

[0168] A portion of the obtained sintered body was ground into a cylindrical shape with a diameter of 1.8 mm and a thickness of 2.8 mm, and then a recess with a diameter of 1.2 mm and a depth of 1.5 mm was formed in the bottom surface of the cylindrical sintered body. In addition, a plurality of microholes with a diameter of 0.1 mm were formed in the top surface of the cylindrical shape by laser processing, thereby obtaining a gas hole member of Example 2.

[0169] (1. Adhesion strength) A dielectric substrate having a thickness of 2.8 mm and a through hole having a diameter of 1.8 mm was used, and except that the gas hole member of Example 2 was press-fitted into the through hole, the adhesion strength of the gas hole member was measured in the same manner as in (1. Adhesion strength) of Example 1. As a result of the test, it was confirmed that the gas hole member of Example 2 did not detach from the gas hole until the dielectric substrate was broken under a load of 400 N.

[0170] (2. Volume Resistivity) The volume resistivity was measured in the same manner as in (2. Volume Resistivity) of Example 1. As a result, the volume resistivity of the sintered body of Example 2 was 1.1 × 10 ５ The value was Ω·cm.

[0171] (3. Discharge Test) An electrostatic chuck device of Example 2 was obtained in the same manner as in (3. Discharge Test) of Example 1, except that the gas hole member of Example 2 was used.

[0172] When evaluated in the same manner as in (3. Discharge test) of Example 1, it was confirmed that no abnormal discharge was observed in the electrostatic chuck device of Example 2, and that discharge was suppressed. Furthermore, the gas hole member did not detach from the through hole from the manufacturing process of the electrostatic chuck device until the completion of the discharge test.

[0173] [Example 3] As a starting material, aluminum oxide (Al ２ O ３ A sintered body of Example 3 was obtained in the same manner as in Example 1, except that only the sintered body of Example 3 was used.

[0174] The sintered body thus obtained was evaluated in the same manner as in Example 1, except that it was used. It was confirmed that the gas hole member did not detach from the gas hole until the dielectric substrate was broken under a load of 400 N.

[0175] Furthermore, the volume resistivity of the sintered body (gas hole member) of Example 3 was measured in the same manner as in Example 1, and was found to be 1.0×10 １１It exceeded Ω·cm.

[0176] Furthermore, a gas hole member was fabricated using the sintered body of Example 3, and an electrostatic chuck device of Example 3 was fabricated in the same manner as in Example 1. As a result of a discharge test, the gas hole member was not detached from the electrostatic chuck device. However, discharge marks were observed on the wafer, and it was found that there is room for improvement in terms of suppressing abnormal discharge.

[0177] [Example 4] Al ２ O ３ The same procedure as in Example 1 was carried out except that the mixing ratio of the particles and SiC particles was changed. １１ A sintered body (gas hole member) of Example 4 having a resistivity of Ω·cm was obtained.

[0178] The sintered body thus obtained was evaluated in the same manner as in Example 1, except that it was used. It was confirmed that the gas hole member did not detach from the gas hole until the dielectric substrate was broken under a load of 400 N.

[0179] Furthermore, a gas hole member was fabricated using the sintered body of Example 4, and an electrostatic chuck device of Example 4 was fabricated in the same manner as in Example 1. As a result of a discharge test, the gas hole member was not detached from the electrostatic chuck device. However, discharge marks were observed on the wafer, and it was found that there is room for improvement in terms of suppressing abnormal discharge.

[0180] Example 5 The same procedure as in Example 2 was repeated except that 20 mass% of SiC particles were used instead of 18 mass%. ３ A sintered body (gas hole member) of Example 5 having a resistivity of Ω·cm was obtained.

[0181] The sintered body obtained in Example 5 was evaluated in the same manner as in Example 2, except that it was used. It was confirmed that the gas hole member did not detach from the gas hole until the dielectric substrate was broken under a load of 400 N.

[0182] Furthermore, a gas hole member was produced using the sintered body of Example 5, and an electrostatic chuck device of Example 5 was produced in the same manner as in Example 2. As a result of conducting a discharge test in the same manner as in Example 1, it was confirmed that no abnormal discharge was observed in the electrostatic chuck device of Example 5, and that discharge was suppressed. Furthermore, the gas hole member did not detach from the through hole from the manufacturing process of the electrostatic chuck device until the completion of the discharge test.

[0183] [Comparative Example 1] The sintered body for the gas hole member obtained in Example 1 was machined to obtain a cylindrical test piece with a diameter of 2 mm and a thickness of 1 mm. A model molded body for Comparative Example 1 was obtained in the same manner as in (1. Adhesion strength) of Example 1, except that the test piece was pressed into the through hole of the dielectric substrate without applying bonding paste to the side surface.

[0184] When the adhesive strength of the test piece in the model molded article was measured in the same manner as in (1. Adhesion strength) of Example 1, the test piece was detached from the dielectric substrate under a load of 100 N.

[0185] Comparative Example 2 A sintered body for a gas hole member of Comparative Example 2 was obtained in the same manner as in Example 1, except that only SiC particles having an average particle size of 0.03 μm were used as the starting material.

[0186] The volume resistivity of the sintered body of Comparative Example 2 was measured in the same manner as in Example 1. As a result, it was found to be 6×10 －３ Ω cm, and 1.0 × 10 ３ It was smaller than Ω·cm.

[0187] In addition, a test piece was prepared by cutting the sintered body of Comparative Example 2, and an adhesive strength test was conducted without applying bonding paste to the side surface of the test piece, as in Comparative Example 1. As a result, the test piece detached from the dielectric substrate under a load of 100 N.

[0188] (3. Discharge Test) A gas hole member was produced using the sintered body of Comparative Example 2, and an electrostatic chuck device of Comparative Example 2 was produced in the same manner as in Example 1. In this test, the insulating paste was applied to the side surface of the gas hole member in the same manner as in Example 1.

[0189] When the electrostatic chuck device of Comparative Example 2 was evaluated in the same manner as in (3. Discharge Test) of Example 1, no discharge traces were observed, but the temperature in the vicinity of the gas hole member rose, and it was confirmed that the plasma resistance was poor.

[0190] From the above results, it was confirmed that when the dielectric substrate and the gas hole member are integrally bonded using a bonding paste, the gas hole member is less likely to detach. This result is clear from a comparison between Example 1 and Comparative Example 1. Furthermore, from these results, it was predicted that if an adhesive strength test were conducted without applying a bonding paste, the test pieces would detach in Examples 2 to 5 as well. Furthermore, it was predicted that with the gas hole member of Comparative Example 2, which is made only of silicon carbide, the test pieces may detach even if a bonding paste is applied. This is because the insulating material contained in the insulating layer and the insulating material contained in the gas hole member do not sinter and are not firmly fixed. Furthermore, when the volume resistivity was 1.1 x 10 ５ The results of Examples 1 and 2 show that the volume resistivity is 1.0 × 10 ３ The result of Example 5 is that the volume resistivity is 1.0 × 10 １１ The results of Examples 3 and 4 show that the volume resistivity is 1.0×10 Ω cm or more. ３ By comparing the results of Comparative Example 2, which has a volume resistivity of less than 1.0 × 10 ３ Ω・cm or more 1.0×10 １０ It was confirmed that a gas hole member with a resistivity of Ω cm or less suppresses abnormal discharge and has good plasma resistance. In this way, it is possible to obtain an excellent electrostatic chuck device in which the gas hole member does not come off, abnormal discharge is suppressed, and further, plasma resistance is good.

[0191] From the above results, it was confirmed that the present invention is useful.

[0192] DESCRIPTION OF SYMBOLS 1A, 1B, 1C Electrostatic chuck device 2A, 2B, 2C Electrostatic chuck plate 2s Mounting surface 2p Back surface 3 Base 3a Support surface 3b Lower surface 11A, 11B, 11C Dielectric substrate 13 Adsorption electrode 15, 111a, 112a, 113a, 115a Through hole 16 Power supply terminal 17 Terminal through hole 21 Power supply 22 High frequency power supply 23 Terminal insulator 24 Insulator 30A, 30B, 30C, 31C Gas hole 31A, 31B First through hole 32 Second through hole 40, 41, 42 Gas hole member 40a Side surface 40b Bottom surface 40x, 41x Recess 42x Lower surface 45A, 45B Support member 45f Foot 45h Hole 45x Upper surface 45y Lower end 49, 135 Insulating layer 55 Adhesive layer 100 Sintered body 110 Main electrode 111, 115 First substrate 111a, 115a Through hole 112 Second substrate 112a Through hole 113, 116 Third substrate 113a Through hole 115x Lower surface of first substrate 120 Guard electrode 130 Counter electrode 131 First electrode 132 Second electrode 135 Insulating layer 200 Test device 210 Pressure terminal 211 Protrusion on mounting surface 220 Pedestal 311 First gas hole 312 Second gas hole 313 Communication path 313x Groove 411 First portion 412 Second portion 412a Upper surface of second portion A Model molded body A1 Dielectric substrate A2 Test piece G Gas

Claims

1. An electrostatic chuck device comprising: a dielectric substrate having a mounting surface on which a sample is mounted; an electrostatic chuck plate having an adsorption electrode located inside the dielectric substrate; and a base supporting the electrostatic chuck plate from the opposite side of the mounting surface, wherein the electrostatic chuck plate has a gas hole continuing from the mounting surface to the surface opposite the mounting surface, and the gas hole is provided with a gas hole member that allows a gas for cooling the sample to pass through and closes the end of the gas hole on the mounting surface side, and the dielectric substrate and the gas hole member contain a common insulating material and are joined together via an insulating layer containing the insulating material.

2. An electrostatic chuck device according to claim 1, wherein the dielectric substrate has a through-hole that constitutes a part of the gas hole and that is complementarily fitted with the gas hole member, and the diameter of the end of the gas hole member that faces the mounting surface is smaller than the diameter of the end of the gas hole member that faces the base.

3. An electrostatic chuck device comprising: a dielectric substrate having a mounting surface on which a sample is placed; an electrostatic chuck plate having an adsorption electrode located inside the dielectric substrate; and a base supporting the electrostatic chuck plate from the opposite side of the mounting surface, wherein the electrostatic chuck plate has a gas hole continuing from the mounting surface to the surface opposite the mounting surface, and the gas hole is provided with a gas hole member that allows a gas for cooling the sample to pass through and closes the end of the gas hole on the mounting surface side, the dielectric substrate has a through hole that constitutes a part of the gas hole and is complementarily fitted with the gas hole member, and the diameter of the end of the gas hole member on the mounting surface side is smaller than the diameter of the end of the gas hole member on the base side.

4. The gas hole member is made of a composite material of an insulating material and a first conductive material, and the volume resistivity of the gas hole member is 1.0×10 １ Ω・cm or more 1.0×10 １０ 4. The electrostatic chuck device according to claim 1, wherein the resistance is Ω·cm or less.

5. The insulating material is Al ２ O ３ 5. The electrostatic chuck device according to claim 4, wherein the first conductive material is SiC.

6. An electrostatic chuck device according to any one of claims 1 to 3, wherein the gas hole member has one or more micropores that penetrate through the member in the thickness direction and have a diameter of 0.03 mm or more and 0.15 mm or less.

7. An electrostatic chuck device according to any one of claims 1 to 3, wherein the gas hole member is a porous body.

8. An electrostatic chuck device according to any one of claims 1 to 3, further comprising a support member inserted into the gas hole and supporting the gas hole member, the support member being a porous body.

9. The dielectric substrate is made of a composite material of an insulating material and a second conductive material, and the volume resistivity of the dielectric substrate is 1.0×10 １３ Ω・cm or more 1.0×10 １７ 4. The electrostatic chuck device according to claim 1, wherein the resistance is Ω·cm or less.

10. An electrostatic chuck device according to any one of claims 1 to 3, wherein the gas holes include a first gas hole that opens on the mounting surface and extends into the interior of the dielectric substrate, a second gas hole that opens on the opposite surface and extends into the interior of the dielectric substrate, and a communication passage that extends inside the dielectric substrate in the direction of the surface of the mounting surface and connects the first gas hole and the second gas hole.

11. A method for manufacturing an electrostatic chuck plate, comprising: a step of fixing a gas hole member to a gas hole provided in a dielectric substrate having a mounting surface for mounting a sample and a built-in chucking electrode, the gas hole member closing the end of the gas hole on the mounting surface side, the dielectric substrate and the gas hole member containing a common insulating material, the fixing step comprising the steps of applying a bonding paste containing the insulating material to either or both of an inner surface of the gas hole or an outer surface of the gas hole member, and inserting the gas hole member into the gas hole, sintering the dielectric substrate and the gas hole member, and bonding the dielectric substrate and the gas hole member via an insulating layer formed from the bonding paste.

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