TWI813840B - Electrostatic chuck device - Google Patents

Abstract

The electrostatic chuck device of the present invention includes: a plurality of internal electrodes; insulating organic films provided on both sides of the internal electrodes in the thickness direction; and ceramic layers laminated with an intermediate layer interposed between at least the internal electrodes and the insulating layer. The upper surface in the thickness direction of the organic film laminate.

Description

Electrostatic chuck device

The present invention relates to electrostatic chuck devices.

Background technology When manufacturing semiconductor integrated circuits using semiconductor wafers, or when manufacturing liquid crystal panels using insulating substrates such as glass substrates and films, it is necessary to adsorb and hold base materials such as semiconductor wafers, glass substrates, and insulating substrates at predetermined locations. Therefore, in order to adsorb and hold these substrates, mechanical chucks or vacuum chucks using mechanical methods have been used in the past. However, these holding methods have the following problems: it is difficult to hold the substrate (adsorbed body) uniformly, they cannot be used in vacuum, and the sample surface temperature rises excessively. Therefore, in recent years, electrostatic chuck devices that can solve the above problems have been used to hold objects to be adsorbed.

The main parts of the electrostatic chuck device include: a conductive support member that serves as an internal electrode; and a dielectric layer composed of a dielectric material covering the conductive support member. The adsorbed object can be adsorbed through this main part. When a voltage is applied to the internal electrodes in the electrostatic chuck device, a potential difference is generated between the adsorbed object and the conductive support member, and an electrostatic adsorption force is generated between the dielectric layers. Thereby, the object to be adsorbed can be supported on the conductive support member substantially flatly.

Regarding the conventional electrostatic chuck device, there is known an electrostatic chuck device in which an insulating organic film is laminated on an internal electrode to form a dielectric layer (see, for example, Patent Document 1). Furthermore, there is known an electrostatic chuck device in which ceramics are thermally sprayed on internal electrodes to form a dielectric layer (for example, see Patent Document 2). Furthermore, there is known an electrostatic chuck device in which ceramic is thermally sprayed on an insulating organic film laminated on an internal electrode to form a ceramic layer (see, for example, Patent Document 3). Advanced technical documents patent documents

[Patent Document 1] Japanese Patent Application Publication No. 2004-235563 [Patent Document 2] Japanese Public Notice No. 6-36583 [Patent Document 3] Japanese Patent No. 5054022

Summary of the invention The problem to be solved by the invention The electrostatic chuck device described in Patent Document 1 uses the Coulomb force formed by a dielectric layer composed of an insulating organic film provided on an internal electrode to adsorb an object to be adsorbed, and has excellent adsorption force. However, this electrostatic chuck device has the following problems: low tolerance in the plasma environment used in dry etching devices and short product life.

Furthermore, the electrostatic chuck device described in Patent Document 2 has a dielectric layer formed by thermally spraying ceramics on internal electrodes, and has plasma resistance. However, due to the existence of gaps between ceramic particles, it is not only difficult to obtain stable insulation, but also the dielectric layer must be thickened to ensure insulation. Therefore, there is a problem that it is difficult to obtain high adsorption force with regard to the electrostatic chuck device that uses Coulomb force to adsorb the adsorbed object.

Furthermore, the electrostatic chuck device described in Patent Document 3 has a ceramic layer formed by thermal spraying ceramic on an insulating organic film laminated on an internal electrode. Since the ceramic layer is thermally sprayed on the insulating organic film, it is necessary to Asperities are formed on the insulating organic film. However, due to the above-mentioned uneven formation or ceramic thermal spraying, the insulation properties of the insulating organic film will be reduced. When used as an electrostatic chuck device, the thickness of the ceramic layer must be at least 100 μm. Furthermore, when ceramics are thermally sprayed on an insulating organic film, the ends of the insulating organic film cannot be covered with the ceramic layer. If the end of the insulating organic film is exposed, the plasma resistance of the electrostatic chuck device is reduced.

The present invention was made in view of the above-mentioned circumstances, and its object is to provide an electrostatic chuck device that has excellent plasma resistance and voltage resistance and is also excellent in adsorption properties. means to solve problems

The present invention has the following aspects. [1] An electrostatic chuck device characterized by having: a plurality of internal electrodes; insulating organic films provided on both sides of the internal electrodes in the thickness direction; and ceramic layers laminated with an intermediate layer interposed between at least The upper surface in the thickness direction of the laminate of the internal electrode and the insulating organic film. [2] The electrostatic chuck device according to [1], wherein the ceramic layer covers the entire outer surface of the laminated body via the intermediate layer. [3] The electrostatic chuck device of [1] or [2], wherein the ceramic layer has: a base layer; and a surface layer formed on the upper surface of the base layer and having unevenness. [4] The electrostatic chuck device according to any one of [1] to [3], wherein the intermediate layer contains: at least one of an organic insulating resin and an inorganic insulating resin; and an inorganic filler and a fibrous filler at least one of the agents. [5] The electrostatic chuck device according to [4], wherein the inorganic filler is at least one of spherical powder and amorphous powder. [6] The electrostatic chuck device of [5], wherein the spherical powder and the amorphous powder system are at least one selected from the group consisting of alumina, silicon oxide and yttrium oxide. [7] The electrostatic chuck device according to any one of [4] to [6], wherein the aforementioned fibrous filler is selected from the group consisting of plant fibers, inorganic fibers and fiberized organic resins. At least 1 species. [8] The electrostatic chuck device according to any one of [1] to [7], wherein the insulating organic film is a polyimide film. [9] The electrostatic chuck device according to any one of [1] to [8], wherein the insulating organic film is composed of a first insulating organic film and a second insulating organic film, and the first insulating organic film The film is provided on the lower surface side in the thickness direction of the aforementioned internal electrode, and the second insulating organic film is provided on the upper surface side in the thickness direction of the aforementioned internal electrode; the first insulating organic film and the aforementioned internal electrode are A first adhesive layer is provided on the opposite side; a second adhesive layer is provided between the first insulating organic film and the internal electrode and the second insulating organic film, and the internal electrode is provided on the second insulating organic film. 1 The upper surface side of the insulating organic film in the thickness direction; the thickness of the aforementioned first adhesive layer, the thickness of the aforementioned first insulating organic film, the thickness of the aforementioned internal electrode, the thickness of the aforementioned second adhesive layer, the thickness of the aforementioned second adhesive layer 2. The total thickness of the insulating organic film, the thickness of the aforementioned intermediate layer, and the thickness of the aforementioned ceramic layer is 200 μm or less. Invention effect

According to the present invention, it is possible to provide an electrostatic chuck device that has excellent plasma resistance and voltage resistance, and also has excellent adsorption properties.

Form used to implement the invention

Hereinafter, an electrostatic chuck device according to an embodiment of the present invention will be described. In addition, in the drawings used in the following description, the dimensional ratios of each component are not necessarily the same as the actual ones. In addition, this embodiment is specifically described in order to better understand the gist of the invention, and is not intended to limit the invention unless otherwise specified.

[Electrostatic chuck device] FIG. 1 shows the schematic structure of the electrostatic chuck device of this embodiment, which is a cross-sectional view along the height direction of the electrostatic chuck device. As shown in FIG. 1 , the electrostatic chuck device 1 of this embodiment includes a substrate 10 , a plurality of internal electrodes 20 , an adhesive layer 30 , an insulating organic film 40 , an intermediate layer 50 and a ceramic layer 60 . Specifically, as shown in FIG. 1 , the electrostatic chuck device 1 of this embodiment includes a substrate 10 , a first internal electrode 21 , a second internal electrode 22 , a first adhesive layer 31 , a second adhesive layer 32 , and a second adhesive layer 32 . 1. Insulating organic film 41, 2nd insulating organic film 42, intermediate layer 50 and ceramic layer 60.

In the electrostatic chuck device 1 of this embodiment, the first adhesive layer 31, the first insulating organic film 41, and the first inner layer are sequentially laminated on the surface 10a of the substrate 10 (the upper surface in the thickness direction of the substrate 10). The electrode 21 and the second internal electrode 22 , the second adhesive layer 32 , the second insulating organic film 42 , the intermediate layer 50 and the ceramic layer 60 .

Insulating organic films 40 are respectively provided on both sides of the internal electrode 20 in the thickness direction (the upper surface 20 a in the thickness direction of the internal electrode 20 and the lower surface 20 b in the thickness direction of the internal electrode 20 ). Specifically, the second insulating organic film 42 is provided on the upper surface 21 a side of the first internal electrode 21 in the thickness direction and on the upper surface 22 a side of the second internal electrode 22 in the thickness direction. Furthermore, a first insulating organic film 41 is provided on the lower surface 21 b side of the first internal electrode 21 in the thickness direction and on the lower surface 22 b side of the second internal electrode 22 in the thickness direction.

The first adhesive layer 31 is provided on the surface of the first insulating organic film 41 opposite to the internal electrode 20 (lower surface 41 b of the first insulating organic film 41 ). The second adhesive layer 32 is provided between the first insulating organic film 41 and the internal electrode 20 and the second insulating organic film 42. The internal electrode 20 is provided in the thickness direction of the first insulating organic film 41. Upper surface 41a.

The thickness of the first adhesive layer 31, the thickness of the first insulating organic film 41, the thickness of the internal electrode 20, the thickness of the second adhesive layer 32, the thickness of the second insulating organic film 42, the thickness of the intermediate layer 50, and The total thickness of the ceramic layer 60 (ceramic base layer 61, ceramic surface layer 62) (hereinafter referred to as "total thickness (1)") is preferably 200 μm or less, preferably 170 μm or less. When the total thickness (1) is 200 μm or less, the electrostatic chuck device 1 has excellent voltage resistance characteristics and plasma resistance, resulting in excellent adsorption force.

The total thickness of the first adhesive layer 31, the thickness of the first insulating organic film 41, the thickness of the internal electrode 20, the thickness of the second adhesive layer 32, and the thickness of the second insulating organic film 42 (hereinafter referred to as " The total thickness (2)") is preferably 110 μm or less, preferably 90 μm or less. When the total thickness (2) is 110 μm or less, the electrostatic chuck device 1 has excellent voltage resistance characteristics and plasma resistance, resulting in excellent adsorption force.

The total thickness of the second adhesive layer 32 and the second insulating organic film 42 (hereinafter referred to as "total thickness (3)") is preferably 50 μm or less, preferably 40 μm or less. When the total thickness (2) is 50 μm or less, the electrostatic chuck device 1 has excellent voltage resistance characteristics and plasma resistance, resulting in excellent adsorption force.

On the upper surface 2 a (upper surface 42 a of the second insulating organic film 42 ) of the laminate 2 including at least the internal electrode 20 and the insulating organic film 40 in the thickness direction, the ceramic layer 60 is laminated via the intermediate layer 50 .

As shown in FIG. 1 , the ceramic layer 60 preferably covers the outer surface of the laminated body 2 (the upper surface 2 a of the laminated body 2 , the side surface (the surface along the thickness direction of the laminated body 2 ), and the first adhesive layer 31 through the intermediate layer 50 the side surface of the second adhesive layer 32, the side surface of the first insulating organic film 41, and the side surface of the second insulating organic film 42) 2b. In other words, the intermediate layer 50 should cover the outside of the laminate 2 The ceramic layer 60 should cover the entire outer surface of the intermediate layer 50 (the upper surface 50a of the intermediate layer 50 and the side surface (the surface along the thickness direction of the laminate 2) 50b) of the intermediate layer 50.

As shown in FIG. 1 , the ceramic layer 60 preferably has a ceramic base layer 61 and a ceramic surface layer 62 formed on the upper surface of the ceramic base layer 61 (the upper surface in the thickness direction of the ceramic base layer 61 ) 61 a and having an uneven surface.

The total thickness of the ceramic base layer 61, the ceramic surface layer 62, the intermediate layer 50, the second adhesive layer 32, and the second insulating organic film 42 (hereinafter referred to as the "total thickness (4)") is preferably 125 μm or less, preferably 110 μm or less. When the total thickness (4) is 125 μm or less, the electrostatic chuck device 1 has excellent voltage resistance characteristics and plasma resistance, resulting in excellent adsorption force.

The first internal electrode 21 and the second internal electrode 22 may be in contact with the first insulating organic film 41 or the second insulating organic film 42 . In addition, as shown in FIG. 1 , the first internal electrode 21 and the second internal electrode 22 may be formed inside the second adhesive layer 32 . The arrangement of the first internal electrode 21 and the second internal electrode 22 can be appropriately designed.

Since the first internal electrode 21 and the second internal electrode 22 are independent, not only voltages of the same polarity but also voltages of different polarities can be applied. The electrode patterns and shapes of the first internal electrode 21 and the second internal electrode 22 are not particularly limited as long as they can attract adsorbed objects such as conductors, semiconductors, and insulators. Alternatively, only the first internal electrode 21 may be provided in the form of a single electrode.

The electrostatic chuck device 1 of this embodiment only has the ceramic layer 60 laminated on the upper surface 42a of the second insulating organic film 42 via the intermediate layer 50, and the structure of the other layers is not particularly limited. For example, the substrate 10 shown in FIG. 1 may not be provided.

The substrate 10 is not particularly limited, and examples thereof include a metal substrate made of a ceramic substrate, a silicon carbide substrate, aluminum, stainless steel, or the like.

The internal electrode 20 is not particularly limited as long as it is made of a conductive material that can exhibit electrostatic attraction when a voltage is applied. For the internal electrode 20 , for example, a thin film made of a metal such as copper, aluminum, gold, silver, platinum, chromium, nickel, tungsten, or a thin film made of at least two metals selected from the above metals can be suitably used. Examples of the metal thin film include those formed by vapor deposition, plating, sputtering, etc., or those formed by applying a conductive paste and drying it, and are specifically metal foils such as copper foil.

As long as the thickness of the second adhesive layer 32 is larger than the thickness of the internal electrode 20, the thickness of the internal electrode 20 is not particularly limited. 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, when the second insulating organic film 42 is formed, unevenness is less likely to occur on the upper surface 42 a. As a result, defects are less likely to occur when the ceramic layer 60 is formed on the second insulating organic film 42 or when the ceramic layer 60 is polished.

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 joint strength can be obtained when the internal electrode 20 is joined to the first insulating organic film 41 or the second insulating organic film 42 .

When voltages with different polarities are applied to the first internal electrode 21 and the second internal electrode 22, it is preferable that the distance between the adjacent first internal electrode 21 and the second internal electrode 22 (the distance in the direction perpendicular to the thickness direction of the internal electrode 20) is less than 2mm. If the distance between the first internal electrode 21 and the second internal electrode 22 is 2 mm or less, sufficient electrostatic force will be generated between the first internal electrode 21 and the second internal electrode 22 to generate sufficient adsorption force.

The distance from the internal electrode 20 to the adsorbed object, that is, the distance from the upper surface 21 a of the first internal electrode 21 and the upper surface 22 a of the second internal electrode 22 to the adsorbed object adsorbed on the ceramic surface layer 62 (existing in the first The total thickness of the second adhesive layer 32, the second insulating organic film 42, the intermediate layer 50, the ceramic base layer 61 and the ceramic surface layer 62 on the upper surface 21a of the internal electrode 21 and the upper surface 22a of the second internal electrode 22 ) should be 50μm~125μm. If the distance from the internal electrode 20 to the adsorbed body is 50 μm or more, the stability of the laminate composed of the second adhesive layer 32, the second insulating organic film 42, the intermediate layer 50, the ceramic base layer 61 and the ceramic surface layer 62 can be ensured. Insulation. On the other hand, if the distance from the internal electrode 20 to the adsorbed body is 125 μm or less, sufficient adsorption force will be generated.

As for the adhesive constituting the adhesive layer 30, an adhesive selected from the group consisting of epoxy resin, phenol resin, styrenic block copolymer, polyamide resin, acrylonitrile-butadiene copolymer, polyester resin, and polyamide is used. Adhesives containing one or more resins such as amine resins, polysiloxy resins, amine compounds, bismaleimide compounds, etc. as the main component.

Examples of epoxy resins include: bisphenol epoxy resin, phenol novolac epoxy resin, cresol novolac epoxy resin, glycidyl ether type epoxy resin, glycidyl ester type epoxy resin, Glycidylamine type epoxy resin, trihydroxyphenylmethane type epoxy resin, tetraepoxypropylphenol alkane type epoxy resin, naphthalene type epoxy resin, diepoxypropyldiphenylmethane type epoxy Resins, bifunctional or multifunctional epoxy resins such as diepoxypropylbiphenyl epoxy resin, etc. Among these, bisphenol type epoxy resin is preferred. Among bisphenol type epoxy resins, bisphenol A type epoxy resin is particularly preferred. In addition, when epoxy resin is used as the main component, epoxy resin hardeners such as imidazoles, third amines, phenols, dicyandiamines, aromatic diamines, and organic peroxides may also be blended as necessary. Hardening accelerator.

Examples of the phenol resin include novolac phenol resins such as alkyl phenol resins, p-phenyl phenol resins, and bisphenol A-type phenol resins, resol phenol resins, and polyphenyl p-phenol resins.

Examples of styrenic block copolymers include styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene- Ethylene-propylene-styrene copolymer (SEPS), etc.

The thickness of the adhesive layer 30 (the first adhesive layer 31 and the 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 (the first adhesive layer 31 and the second adhesive layer 32) is 5 μm or more, it can fully function as an adhesive. On the other hand, if the thickness of the adhesive layer 30 (the first adhesive layer 31 and the second adhesive layer 32) is 20 μm or less, the interelectrode insulation of the internal electrode 20 can be ensured without losing the adsorption force.

The material constituting the insulating organic film 40 is not particularly limited. For example, polyesters such as polyethylene terephthalate, polyolefins such as polyethylene, polyimide, polyamide, and polyamide are used. Imide, polyether sulfide, polyphenylene sulfide, polyether ketone, polyether amide, cellulose triacetate, polysilicone rubber, polytetrafluoroethylene, etc. Among these, polyesters, polyolefins, polyimides, polysiloxane rubbers, polyetherimides, polyether ethylene, and polytetrafluoroethylene are more preferred because of their excellent insulation properties. It is polyimide. Regarding the polyimide film, for example, Kapton (trade name) manufactured by Toray DuPont Co., Ltd., UPILEX (trade name) manufactured by Ube Kosan Co., Ltd., etc. are used.

The thickness of the insulating organic film 40 (the first insulating organic film 41 and the second insulating organic film 42) is not particularly limited, but is preferably 10 μm to 100 μm, more preferably 10 μm to 50 μm. When the thickness of the insulating organic film 40 (the first insulating organic film 41 and the 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 (the first insulating organic film 41 and the second insulating organic film 42) is 100 μm or less, sufficient adsorption force will be generated.

The intermediate layer 50 preferably contains 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.

The organic insulating resin is not particularly limited, and examples thereof include polyimide resin, epoxy resin, acrylic resin, and the like. The inorganic insulating resin is not particularly limited, and examples thereof include silane-based resin, polysiloxane-based resin, and the like.

The middle layer 50 preferably contains polysilazane. Examples of polysilazane include those well known in the field. The polysilazane may be an organic polysilazane or an inorganic polysilazane. These materials may be used individually by 1 type, or in mixture of 2 or more types.

The content of the inorganic filler in the intermediate layer 50 is preferably 100 to 300 parts by mass, preferably 150 to 250 parts by mass relative to 100 parts by mass of polysilazane. If the content of the inorganic filler in the intermediate layer 50 is within the aforementioned range, the inorganic filler particles can form irregularities on the surface of the resin film that is the hardened material of the intermediate layer 50 , so the powder of the thermal spray material can easily bite into the inorganic filler particles. time, the thermal spray material can be firmly adhered to the surface of the aforementioned resin film.

The inorganic filler is not particularly limited, but it is preferably at least one selected from the group consisting of alumina, silicon oxide, and yttrium oxide. The inorganic filler is at least one of spherical powder and amorphous powder. In addition, the so-called spherical powder is a spherical body in which the corners of the powder particles are rounded. In addition, the so-called amorphous powder refers to those that do not take a fixed shape such as broken, plate-like, scaly, needle-like, etc. shapes.

The average particle size of the inorganic filler is preferably 1 μm to 20 μm. When the inorganic filler is a spherical powder, the diameter (outer diameter) is defined as the particle diameter. When the inorganic filler is amorphous powder, the longest position of the shape is defined as the particle diameter.

The fibrous filler is preferably selected from at least one type selected from the group consisting of plant fibers, inorganic fibers and fiberized organic resins. Examples of plant fibers include wood pulp and the like. Examples of inorganic fibers include fibers made of alumina. Examples of the fiberized organic resin include fibers made of aromatic polyamide, Teflon (registered trademark), or the like.

The inorganic filler is preferably used in combination with the fibrous filler, and the total content of the inorganic filler and the fibrous filler is preferably 10% to 80% by volume relative to the entire intermediate layer 50 (100% by volume). If the total content of the inorganic filler and the fibrous filler in the intermediate layer 50 is within the above range, the ceramic layer 60 can be uniformly formed on the intermediate layer 50 by thermal spraying.

The thickness of the intermediate layer 50 is preferably 1 μm ~ 40 μm, preferably 5 μm ~ 20 μm. If the thickness of the intermediate layer 50 is 1 μm or more, the ceramic layer 60 can be uniformly formed on the intermediate layer 50 by thermal spraying without making the intermediate layer 50 locally thinner. On the other hand, if the thickness of the intermediate layer 50 is 40 μm or less, sufficient adsorption force will be generated.

The material constituting the ceramic layer 60 is not particularly limited. For example, boron nitride, aluminum nitride, zirconium oxide, silicon oxide, tin oxide, indium oxide, quartz glass, soda-lime glass, lead glass, borosilicate glass, Zirconium nitride, titanium oxide, etc. These materials may be used individually by 1 type, or in mixture of 2 or more types. These materials are preferably powders with an average particle size of 1 μm to 25 μm. By using the above-mentioned powder, the voids in the ceramic layer 60 can be reduced and the withstand voltage of the ceramic layer 60 can be increased.

The thickness of the ceramic base layer 61 is preferably 10 μm ~ 80 μm, preferably 40 μm ~ 60 μm. If the thickness of the ceramic base layer 61 is 10 μm or more, sufficient plasma resistance and voltage resistance are exhibited. On the other hand, if the thickness of the ceramic base layer 61 is 80 μm or less, sufficient adsorption force will be generated.

The thickness of the ceramic surface layer 62 is preferably 5 μm ~ 20 μm. If the thickness of the ceramic surface layer 62 is 5 μm or more, unevenness can be formed throughout the entire area of the ceramic surface layer 62 . On the other hand, if the thickness of the ceramic surface layer 62 is 20 μm or less, sufficient adsorption force will be generated.

The surface of the ceramic surface layer 62 can be polished to increase its adsorption force, and the unevenness of the surface can be adjusted in the form of surface roughness Ra. Here, the surface roughness Ra refers to a value measured by the method defined in JIS B0601-1994.

The surface roughness Ra of the ceramic surface layer 62 is preferably 0.05 μm~0.5 μm. If the surface roughness Ra of the ceramic surface layer 62 is within the aforementioned range, the adsorbed object can be well adsorbed. If the surface roughness Ra of the ceramic surface layer 62 becomes larger, the contact area between the adsorbed object and the ceramic surface layer 62 becomes smaller, so the adsorption force also becomes smaller.

The electrostatic chuck device 1 of this embodiment described above is provided with: a plurality of internal electrodes 20; insulating organic films 40 provided on both sides of the internal electrodes 20 in the thickness direction; and ceramic layers 60 separated from each other. The intermediate layer 50 is laminated on the upper surface 2 a in the thickness direction of the laminate 2 including at least the internal electrode 20 and the insulating organic film 40 . Therefore, at least on the upper surface 2a side in the thickness direction of the laminated body 2, plasma resistance and voltage resistance can be improved, and abnormal discharge during use can be suppressed. Therefore, the electrostatic chuck device 1 of this embodiment also has excellent adsorption properties.

In the electrostatic chuck device 1 of this embodiment, if the ceramic layer 60 covers the entire outer surface of the laminated body 2 via the intermediate layer 50, plasma resistance can be made on the upper surface 2a side and the side surface 2b side of the laminated body 2. Improved performance and voltage resistance can suppress abnormal discharge during use. Therefore, the electrostatic chuck device 1 of this embodiment has better adsorption properties.

In the electrostatic chuck device 1 of this embodiment, the ceramic layer 60 has the ceramic base layer 61 and the ceramic surface layer 62 formed on the upper surface 61 a of the ceramic base layer 61 and having an uneven surface, so that the desired adsorption force can be controlled.

In the electrostatic chuck device 1 of this embodiment, the intermediate layer 50 contains 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. The ceramic layer 60 is uniformly formed on the intermediate layer 50 .

In the electrostatic chuck device 1 of this embodiment, since the inorganic filler is at least one of spherical powder and amorphous powder, the filling state in the resin in the intermediate layer 50 can be uniformly dispersed or densely packed. By formulating the design in such a manner that part of the filler is exposed from the resin, the adhesion with the ceramic base layer 61 can be improved.

In the electrostatic chuck device 1 of this embodiment, the fibrous filler is at least one selected from the group consisting of plant fibers, inorganic fibers, and fiberized organic resins, so that the intermediate layer 50 can be By arranging fibers on the surface of the intermediate layer 50, the adhesiveness with the ceramic base layer 61 can be improved, and the difference in thermal expansion rates between the ceramic base layer 61 and the insulating organic film 40 separated by the intermediate layer 50 can be alleviated. resulting deformation.

In the electrostatic chuck device 1 of this embodiment, the insulating organic film is a polyimide film, thereby improving the withstand voltage.

In the electrostatic chuck device 1 of this embodiment, the inorganic filler composed of spherical powder and amorphous powder is at least one selected from the group consisting of alumina, silicon oxide, and yttrium oxide. , improving plasma resistance and voltage resistance.

[Manufacturing method of electrostatic chuck] Referring to FIG. 1 , a method of manufacturing the electrostatic chuck device 1 of this embodiment will be described. Metal such as copper is vapor-deposited on the surface 41a of the first insulating organic film 41 (the upper surface 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 specific shape to form the first internal electrode 21 and the second internal electrode 22 .

Next, the second insulating organic film 42 is adhered to the upper surface 20 a of the internal electrode 20 through the second adhesive layer 32 .

Then, the first insulating organic film 41, the internal electrode 20, the second adhesive layer 32 and the second insulating organic film are formed so that the lower surface 41b of the first insulating organic film 41 becomes the surface 10a side of the substrate 10. The laminated body composed of 42 is bonded to the surface 10a of the substrate 10 via the first adhesive layer 31.

Next, the intermediate layer 50 is formed so as to cover the entire outer surface of the laminate 2 including the internal electrode 20 and the insulating organic film 40 . The method of forming the intermediate layer 50 is not particularly limited as long as the intermediate layer 50 can be formed to cover the entire outer surface of the laminated body 2 . Examples of methods for forming the intermediate layer 50 include: rod coating, spin coating, thermal spraying, etc.

Then, the ceramic base layer 61 is formed to cover the entire outer surface of the intermediate layer 50 . An example of a method for forming the ceramic base layer 61 is to apply a slurry containing the material constituting the ceramic base layer 61 to the entire outer surface of the intermediate layer 50 and then sinter it to form the ceramic base layer 61. The material of the layer 61 is thermally sprayed on the entire outer surface of the intermediate layer 50 to form the ceramic base layer 61. Here, the so-called thermal spraying refers to a method of forming a film by heating and melting the material that becomes the film (ceramic base layer 61 in this embodiment) and then injecting the material toward the object to be processed using compressed gas.

Next, a ceramic surface layer 62 is formed on the upper surface 61 a of the ceramic base layer 61 . An example of a method for forming the ceramic surface layer 62 is as follows: after masking the upper surface 61a of the ceramic base layer 61 in a specific shape, the material constituting the ceramic surface layer 62 is thermally sprayed on the upper surface 61a of the ceramic base layer 61 to form the ceramic surface layer 62 The method is to thermally spray the material constituting the ceramic surface layer 62 on the entire upper surface 61a of the ceramic base layer 61 to form the ceramic surface layer 62, and then use sandblasting to cut the ceramic surface layer 62 to form the ceramic surface layer 62 into a concave and convex shape. Methods etc.

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

Hereinafter, the present invention will be described in further detail using Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[Example 1] As the first insulating organic film 41, one side of a polyimide film (trade name: Kapton, manufactured by Toray DuPont Co., Ltd.) with a film thickness of 12.5 μm is plated with copper in a thickness of 9 μm. After the photoresist is coated on the surface of the copper foil, a development process is performed after pattern exposure, and unnecessary copper foil is removed by etching. Then, the copper foil on the polyimide film is washed to remove the photoresist, thereby forming the first internal electrode 21 and the second internal electrode 22 . On the first internal electrode 21 and the second internal electrode 22, an insulating adhesive sheet semi-hardened by drying and heating is laminated as the second adhesive layer 32. Regarding the insulating adhesive sheet, 27 parts by mass of bismaleimide resin, 3 parts by mass of diaminosiloxane, 20 parts by mass of soluble phenolic resin, 10 parts by mass of biphenyl epoxy resin and 240 parts by mass of ethyl acrylate-butyl acrylate-acrylonitrile copolymer were mixed and dissolved in an appropriate amount of tetrahydrofuran, and then formed into a sheet. Then, as the second insulating organic film 42, a polyimide film (trade name: Kapton, manufactured by Toray DuPont Co., Ltd.) having a film thickness of 12.5 μm was adhered, and a laminated body was obtained by adhering it to the second insulating organic film 42 by heat treatment. In addition, the thickness of the second adhesive layer 32 after drying was 20 μm.

Furthermore, on the surface of the first insulating organic film 41 in the above-mentioned laminate that is opposite to the surface on which the first internal electrode 21 and the second internal electrode 22 are formed, a semi-cured insulating adhesive sheet is laminated. A sheet composed of an insulating adhesive with the same composition serves as the first adhesive layer 31 . Then, the laminated body is pasted on the aluminum substrate 10 and bonded by heat treatment. In addition, the thickness of the first adhesive layer 31 after drying was 10 μm.

Then, 100 parts by mass of polysilazane and 200 parts by mass of an inorganic filler (average particle size: 3 μm) made of alumina were mixed with butyl acetate as a dilution medium, and then an ultrasonic disperser was used to make the inorganic filler uniform. Dispersed to make paint.

Next, the paint is sprayed on the surface of the second insulating organic film 42 attached to the laminate of the substrate 10 and the side surface of the laminate 2, and then heated and dried to form the intermediate layer 50. In addition, the thickness of the intermediate layer 50 after drying on the surface of the second insulating organic film 42 is 10 μm.

Next, aluminum oxide (Al ₂ O ₃ ) powder (average particle size: 8 μm) is thermally sprayed on the entire surface of the aforementioned intermediate layer 50 using a plasma thermal spraying method to form a ceramic base layer 61 with a thickness of 50 μm.

Next, after the surface of the ceramic base layer 61 is masked in a specific shape, the above-mentioned aluminum oxide (Al ₂ O ₃ ) powder (average particle size: 8 μm) is thermally sprayed on the surface of the ceramic base layer 61 to form a ceramic surface layer with a thickness of 15 μm. 62.

Then, the adsorption surface of the ceramic surface layer 62 that adsorbs the adsorbed object is plane ground with a diamond grinding stone to obtain the electrostatic chuck device of Embodiment 1. The surface of the obtained electrostatic chuck device was measured according to JIS B0601-1994, and the result was that the surface roughness Ra was 0.3 μm.

[Example 2] The electrostatic chuck device of Example 2 was obtained in the same manner as Example 1, except that the thickness of the first insulating organic film 41 and the thickness of the second insulating organic film 42 in Example 1 were changed to 25 μm.

[Example 3] In addition to changing the thickness of the first insulating organic film 41 and the second insulating organic film 42 to 38 μm, the thickness of the second adhesive layer 32 to 10 μm, and the thickness of the first internal electrode 21 and The electrostatic chuck device of Example 3 was obtained in the same manner as Example 1 except that the thickness of the second internal electrode 22 was changed to 5 μm.

[Comparative example 1] In addition to changing the thickness of the first insulating organic film 41 and the second insulating organic film 42 to 50 μm, the thickness of the ceramic base layer 61 to 30 μm, and the thickness of the intermediate layer 50 to 15 μm in the aforementioned embodiment 1, The electrostatic chuck device of Comparative Example 1 was obtained in the same manner as Example 1, except that the thickness of the first internal electrode 21 and the second internal electrode 22 were changed to 5 μm, and the thickness of the first adhesive layer 31 was changed to 20 μm.

[Comparative example 2] The electrostatic chuck device of Comparative Example 2 was obtained in the same manner as Comparative Example 1, except that the thickness of the ceramic base layer 61 in Comparative Example 1 was changed to 50 μm.

[Comparative example 3] The electrostatic clamp of Comparative Example 3 was obtained in the same manner as Comparative Example 2, except that the thickness of the ceramic surface layer 62 in Comparative Example 2 was changed to 20 μm, the thickness of the ceramic base layer 61 was changed to 80 μm, and the thickness of the intermediate layer 50 was changed to 30 μm. head device.

[Comparative Example 4] Except that the intermediate layer 50 is not provided in the aforementioned Comparative Example 3, the surface of the second insulating organic film 42 is thermally sprayed with aluminum oxide (Al ₂ O ₃ ) powder (average particle size: 8 μm), the electrostatic chuck device of Comparative Example 4 was obtained in the same manner as Comparative Example 3.

Table 1 shows the thickness of each layer and its total value in the electrostatic chuck device obtained in the aforementioned Examples 1 to 3 and Comparative Examples 1 to 4.

[Table 1]

Next, the electrostatic chuck devices obtained in Examples 1 to 3 and Comparative Examples 1 to 4 were used to evaluate withstand voltage characteristics, adsorption force, and plasma resistance. The results are shown in Table 2.

[Evaluation Item] >Withstand voltage characteristics> The withstand voltage characteristics were evaluated by applying a voltage of ±2.5 kV to the first internal electrode 21 and the second internal electrode 22 from a high-voltage power supply device in an electrostatic chuck device under vacuum (10 Pa), and maintaining the voltage for 2 minutes. Observe visually for 2 minutes. If there is no change, it will be regarded as "passed". If there is dielectric breakdown between the electrodes or the insulating organic film and ceramic layer, it will be regarded as "failed".

>Adsorption power> The adsorption force uses a silicon dummy wafer as the adsorbed object, adsorbs it to the surface of the electrostatic chuck device under vacuum (below 10 Pa), and applies a voltage of ±2.5 kV to the first internal electrode 21 and the second internal electrode 22 After that, hold for 30 seconds. While the applied voltage is maintained, helium gas flows in from the through hole provided in the substrate 10, and the leakage amount of the helium gas is measured while increasing the gas pressure. Those who can stably adsorb the dummy wafer at a gas pressure of 100 Torr will be classified as "passed", and those who cannot stably adsorb the dummy wafer will be classified as "failed". The so-called stable adsorption refers to a state in which the wafer will not float due to an increase in helium pressure and the amount of helium leakage will not increase rapidly.

>Plasma resistance> Plasma resistance is determined by visual observation after installing an electrostatic chuck device in a parallel plate type RIE device, introducing oxygen (10 sccm) and carbon tetrafluoride gas (40 sccm) under vacuum (below 20Pa) and high-frequency power supply (output 250W) Changes in the surface condition of the electrostatic chuck device after 24 hours of exposure. If the ceramic layer remains on the entire surface, it will be regarded as "passed", and if part of the ceramic layer disappears and the insulating organic film is exposed, it will be regarded as "failed".

[Table 2] Example 1 Example 2 Example 3 Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Withstand voltage characteristics qualified qualified qualified qualified qualified qualified qualified adsorption force qualified qualified qualified qualified Unqualified Unqualified Unqualified Plasma resistance qualified qualified qualified Unqualified qualified qualified Unqualified

As can be seen from Table 2, the electrostatic chuck device obtained in Examples 1 to 3 was a thin film with a distance of 200 μm or less from the surface 10a of the substrate 10 to the surface of the ceramic surface layer 62, but it was confirmed that the withstand voltage characteristics and plasma resistance were Excellent, resulting in excellent adsorption power.

On the other hand, in the electrostatic chuck device obtained in Comparative Example 1, since the ceramic base layer 61 was thin, sufficient plasma resistance could not be obtained. It was confirmed that the electrostatic chuck devices obtained in Comparative Examples 2 and 3 had poor adsorption force because the distance from the surface 10 a of the substrate 10 to the surface of the ceramic surface layer 62 exceeded 200 μm. Furthermore, it was confirmed that the electrostatic chuck device obtained in Comparative Example 4 did not have the intermediate layer 50 and therefore the ceramic thermal spray material could not sufficiently adhere to the surface of the second insulating organic film 42, resulting in poor plasma resistance. industrial availability

According to the electrostatic chuck device of the present invention, a ceramic layer is laminated on the upper surface in the thickness direction of a laminated body including an internal electrode and an insulating organic film provided on both sides in the thickness direction of the internal electrode via an intermediate layer. It can have excellent plasma resistance and voltage resistance characteristics, and obtain high adsorption force. Therefore, according to the electrostatic chuck device of the present invention, conductors such as wafers or semiconductors used in dry etching equipment in semiconductor manufacturing processes can be stably electrostatically attracted and held.

1: Electrostatic chuck device 2: Laminated body 2a: Upper surface 2b: Side 10:Substrate 10a: Surface 20:Internal electrode 20a: Upper surface 20b: Lower surface 21: 1st internal electrode 21a: Upper surface 21b: Lower surface 22: 2nd internal electrode 22a: Upper surface 22b: Lower surface 30: Adhesive layer 31: 1st adhesive layer 32: 2nd adhesive layer 40: Insulating organic film 41: First insulating organic film 41a: Upper surface 41b: Lower surface 42: Second insulating organic film 42a: Upper surface 50:Middle layer 50a: Upper surface 50b: side 60: Ceramic layer 61: Ceramic base layer 61a: Upper surface 62: Ceramic surface

FIG. 1 shows the schematic structure of the electrostatic chuck device of the present invention, which is a cross-sectional view along the height direction of the electrostatic chuck device.

1: Electrostatic chuck device

2: Laminated body

2a: Upper surface

2b: Side

10:Substrate

10a: Surface

20:Internal electrode

20a: Upper surface

20b: Lower surface

21: 1st internal electrode

21a: Upper surface

21b: Lower surface

22: 2nd internal electrode

22a: Upper surface

22b: Lower surface

30: Adhesive layer

31: 1st adhesive layer

32: 2nd adhesive layer

40: Insulating organic film

41: First insulating organic film

41a: Upper surface

41b: Lower surface

42: Second insulating organic film

42a: Upper surface

50:Middle layer

50a: Upper surface

50b: side

60: Ceramic layer

61: Ceramic base layer

61a: Upper surface

62: Ceramic surface

Claims (7)

An electrostatic chuck device, characterized by having: a plurality of internal electrodes; insulating organic films provided on both sides of the internal electrodes in the thickness direction; and ceramic layers laminated with an intermediate layer interposed between at least the internal electrodes. and the upper surface in the thickness direction of the laminate of the aforementioned insulating organic film; and the aforementioned intermediate layer contains at least one of an organic insulating resin and an inorganic insulating resin, and contains at least one of an inorganic filler and a fibrous filler. One; the aforementioned inorganic filler is at least one of spherical powder and amorphous powder. The electrostatic chuck device according to claim 1, wherein the ceramic layer covers the entire outer surface of the laminated body via the intermediate layer. The electrostatic chuck device of claim 1, wherein the ceramic layer has: a base layer; and a surface layer formed on the upper surface of the base layer and having concavities and convexities. The electrostatic chuck device of claim 1, wherein the spherical powder and the amorphous powder system are at least one selected from the group consisting of alumina, silicon oxide and yttrium oxide. The electrostatic chuck device of claim 1, wherein the fibrous filler is at least one selected from the group consisting of plant fibers, inorganic fibers and fiberized organic resins. The electrostatic chuck device of claim 1, wherein the insulating organic film is a polyimide film. The electrostatic chuck device of Claim 1, wherein the insulating organic film is composed of a first insulating organic film and a second insulating organic film, and the first insulating organic film is disposed in the thickness direction of the internal electrode. On the lower surface side, the second insulating organic film is provided on the upper surface side in the thickness direction of the internal electrode; A first adhesive layer is provided on the surface of the first insulating organic film opposite to the internal electrode; and a first adhesive layer is provided between the first insulating organic film, the internal electrode and the second insulating organic film. The second adhesive layer, the internal electrode is provided on the upper surface side of the thickness direction of the first insulating organic film; the thickness of the first adhesive layer, the thickness of the first insulating organic film, the thickness of the internal electrode The total thickness of the second adhesive layer, the second insulating organic film, the intermediate layer, and the ceramic layer is 200 μm or less.

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