Electrostatic chuck device, sleeve for electrostatic chuck device

Abstract

An electrostatic chuck device (1) is provided with: a substrate (10); a laminate (2) laminated on the upper surface in the thickness direction of the substrate (10); and a ceramic layer (50) laminated on the upper surface in the thickness direction of the laminate (2), wherein a sleeve (70) composed of an insulating material is inserted into a through-hole (60) that penetrates the substrate (10) and the laminate (2) in the thickness direction, the upper surface (71) in the thickness direction of the sleeve (70) is two-staged, composed of a first upper surface (72) that is on the same plane as the upper surface (10a) in the thickness direction of the substrate (10) and a second upper surface (73) that is located above the first upper surface (72) in the thickness direction of the sleeve (70) and is close to the ceramic layer (50), and the edge portion (2A) of the laminate (2) is arranged on the first upper surface (72) when viewed from above.

Description

Technical Field

[0001] This invention relates to an electrostatic chuck device, and a sleeve for the electrostatic chuck device.

[0002] This application claims priority based on Japanese Patent Application No. 2020-055844, filed on March 26, 2020, the contents of which are incorporated herein by reference. Background Technology

[0003] In the manufacture of semiconductor integrated circuits using semiconductor wafers, or in the manufacture of liquid crystal panels using insulating substrates such as glass substrates and films, it is necessary to adsorb and hold substrates such as semiconductor wafers, glass substrates, and insulating substrates in designated locations. Therefore, mechanical methods such as mechanical chucks or vacuum chucks are used to adsorb and hold these substrates. However, these holding methods have problems such as difficulty in uniformly holding the substrate (the adsorbed object), inability to be used in a vacuum, and excessive temperature rise on the sample surface. Therefore, in recent years, electrostatic chuck devices that can solve these problems have been used to hold the adsorbed object.

[0004] The electrostatic chuck device comprises a conductive support member serving as an internal electrode and a dielectric layer made of a dielectric material covering it as its main components. This main component allows for the adsorption of objects. When a voltage is applied to the internal electrode within the electrostatic chuck device, creating a potential difference between the adsorbed object and the conductive support member, an electrostatic attraction force is generated between the dielectric layers. As a result, the adsorbed object is supported substantially flatly on the conductive support member.

[0005] As a conventional electrostatic chuck device, there are known electrostatic chuck devices in which an insulating organic film is stacked on an internal electrode to form a dielectric layer. In such electrostatic chuck devices, a through-hole is provided for holding a semiconductor wafer by means of gas cooling (for example, see Patent Document 1).

[0006] In such electrostatic chuck devices, for example, the following configuration is sometimes used: a substrate; a laminate stacked on the substrate and including internal electrodes; a ceramic layer stacked on the upper surface of the laminate in the thickness direction; an insulating sleeve inserted into a through hole formed for cooling a semiconductor wafer with gas; and a filler layer disposed between the laminate and the insulating sleeve.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: International Publication No. 2004 / 084298 Summary of the Invention

[0010] The technical problem that the invention aims to solve

[0011] In the electrostatic chuck device, sometimes the interfaces of multiple materials with different coefficients of linear expansion are concentrated near the laminate and the insulating sleeve. When the material of the ceramic layer is thermally sprayed onto the laminate, the filler layer thermally expands, and the stress is concentrated at one point, which sometimes causes the ceramic layer to crack.

[0012] In view of the above, the objective of the present invention is to provide an electrostatic chuck device for suppressing cracking of a ceramic layer, and a sleeve for the electrostatic chuck device.

[0013] Technical solutions for solving technical problems

[0014] The present invention has the following aspects.

[0015] [1] An electrostatic chuck device, characterized in that it comprises: a substrate; a laminate stacked on the substrate, including at least an internal electrode; and a ceramic layer stacked on the upper surface of the laminate in the thickness direction, having a through hole in the thickness direction passing through the substrate and the laminate, a sleeve made of insulating material inserted into the through hole, the upper surface of the sleeve in the thickness direction having a two-level structure, consisting of a first upper surface located on the same plane as the upper surface of the substrate in the thickness direction and a second upper surface located above the first upper surface in the thickness direction of the sleeve and close to the ceramic layer, and when viewed from above, the edge of the laminate is disposed on the first upper surface.

[0016] [2] The electrostatic chuck device as described in [1] is characterized in that the ceramic layer has a base layer and a surface layer formed on the upper surface of the base layer and having irregularities.

[0017] [3] A sleeve for an electrostatic chuck device, characterized in that, for an electrostatic chuck device, the upper surface of the sleeve in the thickness direction has a first upper surface and a second upper surface located above the first upper surface in the thickness direction of the sleeve.

[0018] Invention Effects

[0019] According to the present invention, an electrostatic chuck device and a sleeve for the electrostatic chuck device are provided. The electrostatic chuck device uses the heat generated during the formation of the ceramic layer to disperse the stress generated by the thermal expansion of the filler filling between the end face of the laminate, which includes at least an internal electrode and an insulating organic film, and the outer side of the sleeve, thereby suppressing the cracking of the ceramic layer due to said stress. Attached Figure Description

[0020] Figure 1 The schematic configuration of the electrostatic chuck device according to the present invention is shown in a cross-sectional view along the height direction of the electrostatic chuck device.

[0021] Figure 2 This describes the schematic configuration of the electrostatic chuck device according to the present invention, which is to... Figure 1 The diagram shows a magnified view of region α.

[0022] Figure 3 This illustrates the schematic configuration of the electrostatic chuck device in Embodiment 1, which is equivalent to... Figure 1 The diagram shows an enlarged view of region α.

[0023] Figure 4 This illustrates the schematic configuration of the electrostatic chuck device in Embodiment 2, which is equivalent to... Figure 1 The diagram shows an enlarged view of region α.

[0024] Figure 5 This describes the general configuration of the electrostatic chuck device in Comparative Example 1, which is equivalent to... Figure 1 The diagram shows an enlarged view of region α.

[0025] Figure 6 This is a perspective view showing the schematic configuration of the sleeve for the electrostatic chuck device according to the present invention.

[0026] Figure 7 This illustrates the general configuration of the electrostatic chuck device in Comparative Example 2, which is equivalent to... Figure 1 The diagram shows an enlarged view of region α. Detailed Implementation

[0027] The electrostatic chuck device according to an embodiment of the present invention will now be described. It should be noted that the dimensions and proportions of the components in the accompanying drawings used in the following description may not be identical to the actual dimensions. It should also be noted that this specific description is provided to better understand the spirit of the invention and, unless otherwise specified, does not constitute a limitation of the present invention.

[0028] [Electrostatic chuck device]

[0029] (First Implementation)

[0030] Figure 1 The schematic configuration of the electrostatic chuck device according to this embodiment is shown in a cross-sectional view along the height direction of the electrostatic chuck device. Figure 2 The first embodiment, which illustrates the general configuration of the electrostatic chuck device according to the present invention, is to... Figure 1 The diagram shows a magnified view of region α.

[0031] like Figure 1 As shown, the electrostatic chuck device 1 of this embodiment includes: a substrate 10; a laminate 2 including at least a plurality of internal electrodes 20; and a ceramic layer 50 laminated on the upper surface 2a in the thickness direction of the laminate 2.

[0032] In addition to the internal electrode 20, the laminate 2 of the electrostatic chuck device 1 in this embodiment may also include an adhesive layer 30 and an insulating organic film 40. The adhesive layer 30 is composed of a first adhesive layer 31 and a second adhesive layer 32. The insulating organic film 40 is composed of a first insulating organic film 41 and a second insulating organic film 42.

[0033] In the electrostatic chuck device 1 of this embodiment, a first adhesive layer 31, a first insulating organic film 41, an internal electrode 20, a second adhesive layer 32, a second insulating organic film 42, an intermediate layer 90 and a ceramic layer 50 are sequentially stacked on the surface (upper surface in the thickness direction of the substrate 10) 10a of the substrate 10.

[0034] In the electrostatic chuck device 1 of this embodiment, the structure including the internal electrode 20, the first adhesive layer 31, the second adhesive layer 32, the first insulating organic film 41 and the second insulating organic film 42 is referred to as the laminate 2.

[0035] In the electrostatic chuck device 1 of this embodiment, such as Figure 1 As shown, the laminate 2 may also include at least two insulating organic films 40 respectively disposed on both sides (upper surface 20a and lower surface 20b in the thickness direction of the internal electrode 20) of the internal electrode 20. Specifically, a second insulating organic film 42 may be disposed on the upper surface 20a side of the internal electrode 20 in the thickness direction, and a first insulating organic film 41 may be disposed on the lower surface 20b side of the internal electrode 20 in the thickness direction.

[0036] A first adhesive layer 31 is provided on the side of the first insulating organic film 41 opposite to the internal electrode 20 (the lower surface 41b of the first insulating organic film 41). A second adhesive layer 32 is provided between the first insulating organic film 41, the internal electrode 20 disposed on the upper surface 41a of the first insulating organic film 41 in the thickness direction, and the second insulating organic film 42.

[0037] In the electrostatic chuck device 1 of this embodiment, a through hole 60 is provided that penetrates the substrate 10 and the laminate 2 in the thickness direction. A sleeve 70 made of insulating material is inserted into the through hole 60.

[0038] The through hole 60 is used to cool the ceramic layer 50 with gas, or to insert a mold release pin for lifting the adsorbed object attached to the electrostatic chuck device 1.

[0039] The upper surface 71 of the sleeve 70 in the thickness direction has a two-level structure, consisting of a first upper surface 72 located on the same plane as the upper surface 10a of the substrate 10 in the thickness direction, and a second upper surface 73 located above the first upper surface 72 in the thickness direction of the sleeve 70 and close to the ceramic layer 50. That is, in the thickness direction of the substrate 10, the first upper surface 72 of the sleeve 70 has the same height as the upper surface 10a of the substrate 10.

[0040] When observing the electrostatic chuck device 1 from above, as follows: Figure 2 As shown, the edge portion 2A of the laminate 2 is disposed on the first upper surface 72 of the sleeve 70. The length range of the edge portion 2A disposed on the first upper surface 72 of the sleeve 70 in the horizontal direction is not particularly limited, but based on the outer edge 72a of the first upper surface 72, it is preferably 10% to 90% of the length from the outer side surface 70a between the first upper surface 72 and the second upper surface 73 to the outer edge 72a of the first upper surface 72, more preferably 30% to 70%.

[0041] The space between the end face 2b (outer side of edge portion 2A) of the laminate 2 and the outer side 70a (outer side 70a between the first upper surface 72 and the second upper surface 73) of the sleeve 70 can be filled with filler 80 or can be a void.

[0042] like Figure 1 As shown, the ceramic layer 50 preferably has a ceramic base layer 51 and a ceramic surface layer 52 with irregularities formed on the upper surface (the upper surface in the thickness direction of the ceramic base layer 51) 51a of the ceramic base layer 51. Furthermore, a through hole 51b extending through the ceramic base layer 51 in its thickness direction is provided. The inner diameter of the through hole 51b (the diameter perpendicular to the thickness direction of the ceramic base layer 51) is smaller than the inner diameter of the through hole 60 (the diameter perpendicular to the thickness direction of the substrate 10 and the laminate 2).

[0043] The internal electrode 20 can be connected to either the first insulating organic film 41 or the second insulating organic film 42. Additionally, as... Figure 1 As shown, the internal electrode 20 can also be formed inside the second adhesive layer 32. The configuration of the internal electrode 20 can be appropriately designed.

[0044] like Figure 1 As shown, when multiple internal electrodes 20 are independent, voltages of the same polarity or different polarities can be applied. The internal electrodes 20 only need to be able to attract conductors, semiconductors, and insulators; their electrode patterns or shapes are not particularly limited. Alternatively, the internal electrodes 20 may not be independent.

[0045] Although Figure 1In this embodiment, the electrostatic chuck device 1 has a laminate 2, which includes at least an internal electrode 20, stacked on a substrate 10 and a sleeve 70. A ceramic layer 50 is further stacked on the upper surface 2a of the laminate 2, but the substrate 10 may not be present.

[0046] The substrate 10 is not particularly limited and can include ceramic substrates, silicon carbide substrates, metal substrates made of aluminum or stainless steel, etc.

[0047] The internal electrode 20 is not particularly limited, as long as it is made of a conductive material that exhibits electrostatic attraction when a voltage is applied. Preferably, the internal electrode 20 is a thin film made of metals such as copper, aluminum, gold, silver, platinum, chromium, nickel, or tungsten, or a thin film made of at least two metals selected from said metals. Examples of such metal thin films include those formed by vapor deposition, plating, sputtering, or by coating and drying a conductive paste; specifically, examples include metal foils such as copper foil.

[0048] The thickness of the internal electrode 20 is not particularly limited, as long as the thickness of the second adhesive layer 32 is greater than the thickness of the internal electrode 20. The thickness of the internal electrode 20 is preferably 20 μm or less. If the thickness of the internal electrode 20 is 20 μm or less, it is difficult to produce unevenness on its upper surface 42a when forming the second insulating organic film 42. As a result, it is difficult to generate defects when forming the ceramic layer 50 on the second insulating organic film 42 or when grinding the ceramic layer 50.

[0049] The thickness of the internal electrode 20 is preferably 1 μm or more. If the thickness of the internal electrode 20 is 1 μm or more, sufficient bonding strength can be obtained when the internal electrode 20 is bonded to the first insulating organic film 41 or the second insulating organic film 42.

[0050] When voltages of different polarities are applied to the multiple internal electrodes 20, the spacing between adjacent internal electrodes 20 (the spacing in the direction perpendicular to the thickness direction of the internal electrode 20) is preferably 2 mm or less. If the spacing between adjacent internal electrodes 20 is 2 mm or less, sufficient electrostatic force and sufficient adsorption force are generated between adjacent internal electrodes 20.

[0051] The distance from the internal electrode 20 to the adsorbed object, that is, the distance from the upper surface 20a of the internal electrode 20 to the adsorbed object adsorbed on the ceramic surface layer 52 (the sum of the thicknesses of the second adhesive layer 32, the second insulating organic film 42, the ceramic substrate layer 51, and the ceramic surface layer 52 present on the upper surface 20a of the internal electrode 20), is preferably 50 μm to 125 μm. If the distance from the internal electrode 20 to the adsorbed object is 50 μm or more, the insulation of the laminate composed of the second adhesive layer 32, the second insulating organic film 42, the ceramic substrate layer 51, and the ceramic surface layer 52 can be ensured. On the other hand, if the distance from the internal electrode 20 to the adsorbed object is 125 μm or less, sufficient adsorption force is generated.

[0052] As the adhesive constituting the adhesive layer 30, an adhesive whose main component is one or more resins selected from epoxy resin, phenolic resin, styrene block copolymer, polyamide resin, acrylonitrile-butadiene copolymer, polyester resin, polyimide resin, silicone resin, amine compound, bismaleimide compound, etc. can be used.

[0053] Examples of epoxy resins include bisphenol-type epoxy resins, phenol-formaldehyde varnish (novolac) type epoxy resins, cresol-formaldehyde varnish type epoxy resins, glycidyl ether type epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, trihydroxyphenylmethane type epoxy resins, tetraglycidylphenol alkane type epoxy resins, naphthalene type epoxy resins, diglycidyl diphenylmethane type epoxy resins, and diglycidyl biphenyl type epoxy resins, which are difunctional or polyfunctional epoxy resins. Among these, bisphenol-type epoxy resins are preferred. Of the bisphenol-type epoxy resins, bisphenol A type epoxy resins are particularly preferred. Furthermore, when epoxy resin is the main component, imidazoles, tertiary amines, phenols, dicyandiamides, aromatic diamines, organic peroxides, and other epoxy resin curing agents or curing accelerators can be added as needed.

[0054] Phenolic resins include alkylphenol resins, p-phenylphenol resins, bisphenol A type phenol resins, methyl phenol resins, and polyphenylene-p-phenol resins.

[0055] Examples of styrene-based block copolymers include styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), and styrene-ethylene-propylene-styrene copolymer (SEPS).

[0056] The thickness of the adhesive layer 30 (first adhesive layer 31 and second adhesive layer 32) is not particularly limited, but is preferably 5 μm to 20 μm, more preferably 10 μm to 20 μm. If the thickness of the adhesive layer 30 (first adhesive layer 31 and second adhesive layer 32) is 5 μm or more, the adhesive function is fully utilized. On the other hand, if the thickness of the adhesive layer 30 (first adhesive layer 31 and second adhesive layer 32) is 20 μm or less, the inter-electrode insulation of the internal electrode 20 can be ensured without compromising the adsorption force.

[0057] The materials constituting the insulating organic film 40 are not particularly limited, and can include polyesters such as polyethylene terephthalate, polyolefins such as polyethylene, polyimide, polyamide, polyamide-imide, polyethersulfone, polyphenylene sulfide, polyetherketone, polyetherimide, triacetyl cellulose, silicone rubber, polytetrafluoroethylene, etc. Among these, polyesters, polyolefins, polyimide, silicone rubber, polyetherimide, polyethersulfone, and polytetrafluoroethylene are preferred for excellent insulation properties, and polyimide is more preferred. For example, Kapton (trade name) manufactured by DuPont-Toray and UPILEX (trade name) manufactured by Ube Industries, Ltd. can be used as polyimide films.

[0058] The thickness of the insulating organic film 40 (first insulating organic film 41 and second insulating organic film 42) is not particularly limited, but is preferably 10 μm to 100 μm, more preferably 10 μm to 50 μm. If the thickness of the insulating organic film 40 (first insulating organic film 41 and second insulating organic film 42) is 10 μm or more, insulation can be ensured. On the other hand, if the thickness of the insulating organic film 40 (first insulating organic film 41 and second insulating organic film 42) is 100 μm or less, sufficient adsorption force is generated.

[0059] Alternatively, a ceramic plate made of ceramic material can be used instead of the insulating organic film 40 (first insulating organic film 41, second insulating organic film 42).

[0060] The through-hole 60 penetrates the substrate 10 and the laminate 2 in the thickness direction, but its shape when viewed from above (the shape viewed from the upper surface 51a side of the ceramic substrate 51) is not particularly limited. Examples of the shape of the through-hole 60 when viewed from above include circles and rectangles. The inner diameter of the through-hole 60 is not particularly limited, but is preferably 5 mm to 15 mm, and more preferably 5 mm to 13 mm. The inner diameter of the through-hole 60 refers to: the diameter of the through-hole 60 when its shape when viewed from above is circular; and the length of the longest part of the through-hole 60 when its shape when viewed from above is not circular.

[0061] Examples of insulating materials constituting the sleeve 70 include aluminum oxide, yttrium oxide, zirconium oxide, and resin.

[0062] like Figure 6 As shown, the sleeve 70 is a cylindrical component with a first upper surface 72 and a second upper surface 73 located above the first upper surface in the thickness direction of the sleeve. The sleeve 70 has a through hole 75 near its cylindrical center. The through hole 75 is for cooling the ceramic layer 50 with gas or for inserting a mold-lifting pin or similar device to lift an object attached to the electrostatic chuck device 1. The cross-sectional shape of the sleeve 70 perpendicular to its length direction is not particularly limited and can be appropriately set according to the shape of the through hole 60 when viewed from above.

[0063] The diameter of the through hole 75 in the sleeve 70 is not particularly limited, but is preferably 0.5 mm to 5 mm, and more preferably 0.3 mm to 3 mm.

[0064] The sleeve 70 can be manufactured by molding the insulating material using a mold, or by cutting the insulating material into columnar shapes.

[0065] The outer diameter of the sleeve 70 extending downwards from the first upper surface 72 (in the thickness direction of the sleeve 70) is not particularly limited, but is preferably 4mm to 15mm, more preferably 4mm to 10mm. Similarly, the outer diameter of the sleeve 70 extending upwards from the first upper surface 72 (in the thickness direction of the sleeve 70) is not particularly limited, but is preferably 1mm to 7mm, more preferably 2mm to 4mm. The outer diameter of the sleeve 70 refers to: the diameter of the cross-section perpendicular to the length direction of the sleeve 70 when the cross-sectional shape is circular; and the length of the longest portion of the cross-section perpendicular to the length direction of the sleeve 70 when the cross-sectional shape is not circular.

[0066] The size of the first upper surface 72 of the sleeve 70 is not particularly limited. For example, the length from the outer side 70a between the first upper surface 71 and the second upper surface 72 to the outer edge 72a of the first upper surface 72 is preferably 1 mm to 5 mm, more preferably 1 mm to 3 mm.

[0067] As filler 80, an adhesive is used.

[0068] As an adhesive, there are no particular limitations, but examples include epoxy resin, polyimide resin, acrylic resin, silane resin, and silicone resin.

[0069] There are no particular limitations on the materials constituting the ceramic layer 50. For example, boron nitride, aluminum nitride, aluminum oxide (aluminum oxide), zirconium oxide, silicon oxide, tin oxide, indium oxide, quartz glass, soda glass, lead glass, borosilicate glass, zirconium nitride, titanium oxide, etc., can be used, with aluminum oxide being preferred. These materials can be used alone or in combination.

[0070] These materials are preferably powders with an average particle size of 1 μm to 25 μm. By using such powders, the porosity of the ceramic layer 50 can be reduced, thereby improving the voltage resistance of the ceramic layer 50.

[0071] The thickness of the ceramic substrate 51 is preferably 10 μm to 80 μm, more preferably 40 μm to 60 μm. If the thickness of the ceramic substrate 51 is 10 μm or more, sufficient plasma resistance and voltage resistance are exhibited. On the other hand, if the thickness of the ceramic substrate 51 is 80 μm or less, sufficient adsorption force is generated.

[0072] The thickness of the ceramic surface layer 52 is preferably 5 μm to 20 μm. If the thickness of the ceramic surface layer 52 is 5 μm or more, it can form an uneven surface covering the entire area of ​​the ceramic surface layer 52. On the other hand, if the thickness of the ceramic surface layer 52 is 20 μm or less, sufficient adsorption force is generated.

[0073] The ceramic surface layer 52 can improve its adsorption force by grinding its surface, and can adjust the surface roughness Ra of its surface unevenness.

[0074] Among them, surface roughness Ra refers to the value measured by the method specified in JIS B0601-1994.

[0075] The surface roughness Ra of the ceramic surface layer 52 is preferably 0.05 μm to 0.5 μm. If the surface roughness Ra of the ceramic surface layer 52 is within this range, the adsorbed object can be well adsorbed. If the surface roughness Ra of the ceramic surface layer 52 increases, the adsorption force will also decrease because the contact area between the adsorbed object and the ceramic surface layer 52 becomes smaller.

[0076] In the electrostatic chuck device 1 of this embodiment, such as Figure 1 As shown, a ceramic layer 50 may also be stacked on the upper surface 2a (upper surface 42a of the second insulating organic film 42) of the laminate 2, which includes at least the internal electrode 20, in the thickness direction, with an intermediate layer 90 in between.

[0077] The intermediate layer 90 preferably comprises at least one of an organic insulating resin and an inorganic insulating resin, and at least one of an inorganic filler and a fibrous filler.

[0078] As an organic insulating resin, there are no particular limitations; examples include polyimide resins, epoxy resins, and acrylic resins.

[0079] As an inorganic insulating resin, there are no particular limitations; for example, silane resins and silicone resins can be listed.

[0080] The intermediate layer 90 preferably contains a polysilazane. Examples of polysilazanes well-known in the art include, for instance, organic or inorganic polysilazanes. These materials can be used alone or in combination.

[0081] The content of inorganic filler in the intermediate layer 90 is preferably 100 to 300 parts by weight, more preferably 150 to 250 parts by weight, relative to 100 parts by weight of polysilazane. If the content of inorganic filler in the intermediate layer 90 is within the specified range, the inorganic filler particles can form unevenness on the surface of the resin film, which is the cured product of the intermediate layer 90. Therefore, the powder of the spraying material can easily penetrate between the inorganic filler particles, enabling the spraying material to adhere firmly to the surface of the resin film.

[0082] As an inorganic filler, there is no particular limitation, but it is preferably selected from at least one of the group consisting of aluminum oxide, silicon dioxide and yttrium oxide, and more preferably aluminum oxide.

[0083] The inorganic filler is preferably at least one of spherical powder and amorphous powder. It should be noted that spherical powder refers to a sphere with the corners of the powder particles rounded. Furthermore, amorphous powder refers to powders that do not conform to a specific shape, such as broken, plate-like, flaky, or needle-like particles.

[0084] The average particle size of the inorganic filler is preferably 1 μm to 20 μm. When the inorganic filler is a spherical powder, its diameter (outer diameter) is used as the particle size; when the inorganic filler is an amorphous powder, the longest part of its shape is used as the particle size.

[0085] The fibrous filler is preferably at least one selected from the group consisting of plant fibers, inorganic fibers, and fibrous organic resins.

[0086] Examples of plant fibers include paper pulp.

[0087] As inorganic fibers, examples include fibers composed of aluminum oxide.

[0088] As a type of fibrous organic resin, fibers composed of aramid or Teflon (registered trademark) can be listed.

[0089] The inorganic filler is preferably used in combination with the fibrous filler, and the total content of the inorganic filler and the fibrous filler relative to the entire intermediate layer 90 (100 vol%) is preferably 10 vol% to 80 vol%. If the total content of the inorganic filler and the fibrous filler in the intermediate layer 90 is within the above range, a ceramic layer can be uniformly formed on the intermediate layer 90 by spraying.

[0090] The thickness of the intermediate layer 90 is preferably 1 μm to 40 μm, more preferably 5 μm to 20 μm. If the thickness of the intermediate layer 90 is 1 μm or more, the intermediate layer 90 will not become locally thinner, and the ceramic layer 50 can be uniformly formed on the intermediate layer 90 by spraying. On the other hand, if the thickness of the intermediate layer 90 is 40 μm or less, sufficient adsorption force is generated.

[0091] In the electrostatic chuck device 1 of this embodiment described above, a through hole 60 is provided that penetrates the substrate 10 and the laminate 2 along the thickness direction. A sleeve 70 is inserted into the through hole 60. The upper surface 71 of the sleeve 70 in the thickness direction has a two-level structure, consisting of a first upper surface 72 located on the same plane as the upper surface 10a of the substrate 10 in the thickness direction, and a second upper surface 73 located above the first upper surface 72 in the thickness direction of the sleeve 70 and close to the ceramic layer 50. When viewed from above, the edge portion 2A of the laminate 2 is disposed on the first upper surface 72. Therefore, the stress generated by the thermal expansion of the filler 80 filled between the end face 2b of the laminate 2 and the outer surface 70a of the sleeve 70 can be dispersed by the heat generated when forming the ceramic layer 50, thereby suppressing the cracking of the ceramic layer 50 (especially the ceramic substrate layer 51) due to the aforementioned stress.

[0092] In the electrostatic chuck device 1 of this embodiment, the ceramic layer 50 has a ceramic base layer 51 and a ceramic surface layer 52 formed on the upper surface 51a of the ceramic base layer 51 with irregularities, thereby enabling control of the desired adsorption force.

[0093] In the electrostatic chuck device 1 of this embodiment, when the insulating organic film is a polyimide film, the voltage resistance is further improved.

[0094] [Manufacturing method of electrostatic chuck]

[0095] Reference Figure 1 The manufacturing method of the electrostatic chuck device 1 of this embodiment will be described.

[0096] A metal such as copper is deposited on the surface 41a of the first insulating organic film 41 (the upper surface 41a in the thickness direction of the first insulating organic film 41) to form a metal thin film. Then, etching is performed to pattern the metal thin film into a predetermined shape to form the internal electrode 20.

[0097] Next, a second insulating organic film 42 is attached to the upper surface 20a of the internal electrode 20 using a second adhesive layer 32.

[0098] Next, a first adhesive layer 31 is formed on the side opposite to the side of the first insulating organic film 41 where the internal electrode 20 is formed, resulting in a laminate 2 consisting of the first adhesive layer 31, the first insulating organic film 41, the internal electrode 20, the second adhesive layer 32, and the second insulating organic film 42.

[0099] Next, laser light is irradiated from the surface of the laminate 2 (the surface of the second insulating organic film 42) to form a hole on the laminate that matches the through hole 60 in the substrate 10.

[0100] On the other hand, after forming a through hole 60 on the substrate 10 using a drill bit or the like, a sleeve 70 having a two-stage structure consisting of the first upper surface 72 and the second upper surface 73 is joined inside the through hole 60.

[0101] Next, the perforated laminate 2 is bonded to the surface 10a of the substrate 10 and the first upper surface 72 of the sleeve 70 by the first adhesive layer 31.

[0102] Next, after forming an intermediate layer 90 on the entire outer surface of the laminate 2, which is stacked on the surface 10a of the substrate 10 and the first upper surface 72 of the sleeve 70, and on the second upper surface 73 of the sleeve 70, a ceramic substrate layer 51 is formed in such a way that it covers the entire outer surface of the intermediate layer 90.

[0103] Methods for forming the ceramic substrate 51 may include, for example, coating a slurry comprising the material constituting the ceramic substrate 51 onto the entire outer surface of the intermediate layer 90 and sintering it to form the ceramic substrate 51; or spraying the material constituting the ceramic substrate 51 onto the entire outer surface of the intermediate layer 90 to form the ceramic substrate 51.

[0104] Spray coating refers to a method of forming a film by heating and melting a material used as a coating (in this embodiment, a ceramic substrate layer 51) and then spraying it onto the workpiece using compressed gas.

[0105] Next, a ceramic surface layer 52 is formed on the upper surface 51a of the ceramic substrate layer 51.

[0106] Methods for forming the ceramic surface layer 52 may include, for example, applying a mask of a predetermined shape to the upper surface 51a of the ceramic substrate layer 51 and then spraying the material constituting the ceramic surface layer 52 onto the upper surface 51a of the ceramic substrate layer 51 to form the ceramic surface layer 52; or spraying the material constituting the ceramic surface layer 52 onto the entire upper surface 51a of the ceramic substrate layer 51 to form the ceramic surface layer 52, and then cutting the ceramic surface layer 52 by a blown process to form the ceramic surface layer 52 into an uneven shape.

[0107] Through the above procedures, the electrostatic chuck device 1 of this embodiment can be manufactured.

[0108] Example

[0109] The present invention will now be described in further detail through examples and comparative examples, but the present invention is not limited to the following examples.

[0110] [Example 1]

[0111] A 9μm thick copper layer is deposited on one surface of a 12.5μm thick polyimide film (trade name: Kapton, Du Pont-Toray) as a first insulating organic film 41. After coating the copper foil surface with photoresist, a development process is performed after pattern exposure, and unwanted copper foil is removed by etching. Then, the photoresist is removed by cleaning the copper foil on the polyimide film, forming an internal electrode 20. An insulating adhesive sheet that is semi-cured by drying and heating is laminated on the internal electrode 20 as a second adhesive layer 32. As the insulating adhesive sheet, a sheet-like insulating adhesive sheet is formed by dissolving 27 parts by weight of bismaleimide resin, 3 parts by weight of diaminosiloxane, 20 parts by weight of methylphenolic resin, 10 parts by weight of biphenyl epoxy resin, and 240 parts by weight of ethyl acrylate-butyl acrylate-acrylonitrile copolymer in an appropriate amount of tetrahydrofuran. Then, a 12.5 μm thick polyimide film (trade name: Kapton, manufactured by DuPont-Toray) is pasted on as the second insulating organic film 42, and bonded by heat treatment to obtain the laminate 2. It should be noted that the thickness of the dried second adhesive layer 32 is 20 μm.

[0112] Furthermore, a sheet made of insulating adhesive with the same composition as the semi-cured insulating adhesive sheet is stacked on the surface opposite to the surface of the internal electrode 20 in which the first insulating organic film 41 is formed, as the first adhesive layer 31, and a hole is formed by the laser beam in conjunction with the through hole 60 in the substrate 10.

[0113] On the other hand, after forming a through hole 60 on the substrate 10 using a drill bit or the like, a sleeve 70 is joined inside the through hole 60. The sleeve 70 has a two-level structure consisting of a first upper surface 72 and a second upper surface 73, and is formed of aluminum oxide (Al2O3). Then, the laminate 2 is bonded to the aluminum substrate 10, and heat treatment is performed to bond it. It should be noted that the thickness of the first adhesive layer 31 after drying is 10 μm.

[0114] Next, 100 parts by weight of polysilazane and 200 parts by weight of inorganic filler composed of aluminum oxide (average particle size: 3 μm) are mixed into butyl acetate as a diluent, and then the inorganic filler is uniformly dispersed using an ultrasonic disperser to produce a coating.

[0115] Next, the coating is sprayed onto the surface of the second insulating organic film 42 bonded to the substrate 10, and then heated and dried to form an intermediate layer 90. It should be noted that the thickness of the dried intermediate layer 90 on the surface of the second insulating organic film 42 is 10 μm.

[0116] Next, aluminum oxide (Al2O3) powder (average particle size: 8μm) is sprayed onto the upper surface of the intermediate layer 50 by plasma spraying to form a ceramic substrate layer 51 with a thickness of 50μm.

[0117] Next, after masking the surface of the ceramic substrate 51 in a specified shape, the above-mentioned aluminum oxide (Al2O3) powder (average particle size: 8μm) is sprayed onto the surface of the ceramic substrate 51 to form a ceramic surface layer 52 with a thickness of 15μm.

[0118] Next, the adsorption surface of the ceramic surface 52, which adsorbs the adsorbed material, is ground with a diamond grinding wheel to obtain... Figure 3 The electrostatic chuck device of Embodiment 1 is shown. Figure 3 In the text, the unevenness in the outer surface of the ceramic layer 50 formed by the ceramic surface layer 52 is omitted.

[0119] In the obtained electrostatic chuck device, the first upper surface 72 of the sleeve 70 is provided with the edge portion 2A of the laminate 2. Based on the outer edge 72a of the first upper surface 72, the length of the edge portion 2A on the first upper surface 72 in the horizontal direction is 75% of the length from the outer side 70a between the first upper surface 72 and the second upper surface 73 to the outer edge 72a of the first upper surface 72.

[0120] For the obtained electrostatic chuck device, the presence of cracks in the ceramic layer 50 was visually inspected. Cases without cracks were rated as "○", and cases with cracks were rated as "×". The results are shown in Table 1.

[0121] [Example 2]

[0122] In Embodiment 1, taking the outer edge 72a of the first upper surface 72 as a reference, and with the length of the edge portion 2A on the first upper surface 72 in the horizontal direction being 30% of the length from the outer side 70a between the first upper surface 72 and the second upper surface 73 to the outer edge 72a of the first upper surface 72, the edge portion 2A of the laminate 2 is disposed on the first upper surface 72 of the sleeve 70. Otherwise, it is the same as in Embodiment 1, resulting in… Figure 4 The electrostatic chuck device of Embodiment 2 is shown.

[0123] For the obtained electrostatic chuck device, the presence or absence of cracks in the ceramic layer 50 was confirmed in the same manner as in Example 1. The results are shown in Table 1.

[0124] [Comparative Example 1]

[0125] In Embodiment 1, except that the edge portion 2A of the laminate 2 is not disposed on the first upper surface 72 of the sleeve 70, it is the same as in Embodiment 1, resulting in... Figure 5 The electrostatic chuck device of Comparative Example 1 is shown.

[0126] For the obtained electrostatic chuck device, the presence or absence of cracks in the ceramic layer 50 was confirmed in the same manner as in Example 1. The results are shown in Table 1.

[0127] [Comparative Example 2]

[0128] In Embodiment 1, except that the upper surface 71 of the sleeve 70 is not a two-stage structure and the edge 2A of the laminate 2 is not disposed on the first upper surface 72 of the sleeve 70, it is the same as in Embodiment 1, resulting in... Figure 7 The electrostatic chuck device 100 of Comparative Example 2 is shown.

[0129] For the obtained electrostatic chuck device, the presence or absence of cracks in the ceramic layer 50 was confirmed in the same manner as in Example 1. The results are shown in Table 1.

[0130] [Table 1]

[0131] Example 1 Example 2 Comparative Example 1 Comparative Example 2 Are there any cracks in the ceramic layer? ○ ○ × ×

[0132] The results in Table 1 confirm that by making the upper surface 71 of the sleeve 70 a two-level structure consisting of a first upper surface 72 and a second upper surface 73, and by placing the edge 2A of the laminate 2 on the first upper surface 72, it is possible to suppress the cracking of the ceramic layer 50.

[0133] Industrial applicability

[0134] According to the electrostatic chuck device of the present invention, through holes 60, such as air supply holes (molding pin holes), are provided to penetrate the substrate and the laminate in the thickness direction. A sleeve is inserted into the through holes. The upper surface of the sleeve in the thickness direction has a two-level structure, consisting of a first upper surface located on the same plane as the upper surface of the substrate in the thickness direction and a second upper surface located above the first upper surface in the thickness direction of the sleeve and close to the ceramic layer. When viewed from above, the edge portion of the laminate is disposed on the first upper surface. Therefore, the stress generated by the thermal expansion of the filler between the end face of the laminate and the outer surface of the sleeve due to the heat generated during the formation of the ceramic layer can be dispersed, thereby suppressing the cracking of the ceramic layer due to the stress.

[0135] Explanation of reference numerals in the attached figures

[0136] 1: Electrostatic chuck device; 2: Laminated body; 10: Substrate; 20: Internal electrode; 30: Adhesive layer; 31: First adhesive layer; 32: Second adhesive layer; 40: Insulating organic film; 41: First insulating organic film; 42: Second insulating organic film; 50: Ceramic layer; 51: Ceramic substrate layer; 52: Ceramic surface layer; 60: Through hole; 70: Sleeve; 71: Upper surface; 72: First upper surface; 73: Second upper surface; 75: Through hole; 80: Filler; 90: Intermediate layer.

Claims

1. An electrostatic chuck device, characterized in that, The electrostatic chuck device comprises: a substrate; a laminate stacked on the substrate, including at least internal electrodes; and a ceramic layer stacked on the upper surface of the laminate in the thickness direction. The electrostatic chuck device is provided with a through hole that penetrates the substrate and the laminate in the thickness direction. A sleeve made of insulating material is inserted into the through hole. The upper surface of the sleeve in the thickness direction has a two-level structure consisting of a first upper surface and a second upper surface. The first upper surface is located on the same plane as the upper surface of the substrate in the thickness direction. The second upper surface is located above the first upper surface in the thickness direction of the sleeve and is close to the second upper surface of the ceramic layer. When viewed from above, the edges of the laminate are positioned on the first upper surface. The outer side of the edge of the laminate is filled with a filler or a gap between the outer side of the first upper surface and the second upper surface.

2. The electrostatic chuck device according to claim 1, characterized in that, The ceramic layer has: a base layer; and a surface layer, formed on the upper surface of the base layer in the thickness direction and having irregularities.

Images