JP7256310B2 - Electrostatic chuck device - Google Patents

Description

The present invention relates to an electrostatic chuck device.

When manufacturing a semiconductor integrated circuit using a semiconductor wafer, or when manufacturing a liquid crystal panel using an insulating substrate such as a glass substrate or film, the base material such as a semiconductor wafer, glass substrate, or insulating substrate must be used. It is necessary to adsorb and hold it at a predetermined site. Therefore, mechanical chucks, vacuum chucks, and the like using mechanical methods have been used to attract and hold these substrates. However, these holding methods have problems such as difficulty in holding the substrate (adsorbable body) uniformly, inability to use in a vacuum, excessive temperature rise of the sample surface, and the like. Therefore, in recent years, an electrostatic chuck device capable of solving these problems has been used to hold the object to be attracted.

An electrostatic chuck device mainly includes a conductive support member that serves as an internal electrode and a dielectric layer that covers the support member and is made of a dielectric material. The body to be adsorbed can be adsorbed by this main portion. When a voltage is applied to the internal electrodes in the electrostatic chuck device to generate a potential difference between the object to be attracted and the conductive support member, an electrostatic attraction force is generated between the dielectric layers. As a result, the object to be adsorbed is supported substantially flat on the conductive support member.

As a conventional electrostatic chuck device, an electrostatic chuck device is known in which an insulating organic film is laminated on an internal electrode to form a dielectric layer (see, for example, Patent Document 1). Also known is an electrostatic chuck device in which a dielectric layer is formed by thermally spraying ceramics on internal electrodes (see, for example, Patent Document 2). Also known is an electrostatic chuck device in which a ceramic layer is formed by spraying ceramics onto an insulating organic film laminated on an internal electrode (see, for example, Patent Document 3).

JP-A-2004-235563 Japanese Utility Model Publication No. 6-36583 Japanese Patent No. 5054022

An electrostatic chuck device that adsorbs an object to be adsorbed by a Coulomb force formed by a dielectric layer made of an insulating organic film provided on an internal electrode, as described in Patent Document 1, has excellent adsorption force. ing. However, this electrostatic chuck device has a problem that it has a low durability in a plasma environment used in a dry etching device and has a short product life.

Further, an electrostatic chuck device having a dielectric layer formed by thermally spraying ceramics on an internal electrode, as described in Patent Document 2, has plasma resistance. However, since voids exist between ceramic particles, it is difficult to obtain stable insulation, and the dielectric layer must be thickened to ensure insulation. Therefore, there is a problem that it is difficult to obtain a high adsorption force as an electrostatic chuck device that adsorbs an object to be adsorbed by Coulomb force.

In addition, as described in Patent Document 3, in an electrostatic chuck device having a ceramic layer formed by thermally spraying ceramics on an insulating organic film laminated on an internal electrode, the ceramic layer is formed on the insulating organic film. In order to thermally spray form the insulating organic film, it was necessary to form irregularities on the insulating organic film. However, the formation of unevenness and thermal spraying of ceramics deteriorate the insulating properties of the insulating organic film, and the thickness of the ceramics layer must be at least 100 μm for use as an electrostatic chuck device. Moreover, when the ceramics were thermally sprayed onto the insulating organic film, it was not possible to cover the edges of the insulating organic film with the ceramic layer. If the edge of the insulating organic film is exposed, the plasma resistance of the electrostatic chuck device is lowered.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electrostatic chuck device that has excellent plasma resistance and voltage resistance, as well as excellent adsorption properties.

The present invention has the following aspects.
[1] a plurality of internal electrodes, insulating organic films provided on both sides of the internal electrodes in the thickness direction, and a laminate including at least the internal electrodes and the insulating organic films, and and a ceramic layer laminated via an intermediate layer,
The electrostatic chuck device, wherein the intermediate layer 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.
[2] The electrostatic chuck device according to [1], wherein the inorganic filler is at least one of spherical powder and amorphous powder.
[3] The electrostatic chuck device according to [2], wherein the spherical powder and the amorphous powder are at least one selected from the group consisting of alumina, silica and yttria.
[4] Any one of [1] to [3], wherein the fibrous filler is at least one selected from the group consisting of vegetable fibers, inorganic fibers and fibrous organic resins. An electrostatic chuck device as described.
[5] The electrostatic chuck device according to [1], wherein the ceramic layer has an underlying layer and a surface layer having unevenness formed on the upper surface of the underlying layer.
[6] The electrostatic chuck device according to any one of [1] to [5], wherein the insulating organic film is a polyimide film.
[7] The insulating organic film includes a first insulating organic film provided on the lower surface side of the internal electrode in the thickness direction and a second insulating organic film provided on the upper surface side of the internal electrode in the thickness direction. made of organic film,
A first adhesive layer is provided on the surface of the first insulating organic film opposite to the internal electrode,
A second adhesive layer is provided between the first insulating organic film and the second insulating organic film and the internal electrode provided on the upper surface side of the first insulating organic film in the thickness direction. provided,
Thickness of the first adhesive layer, thickness of the first insulating organic film, thickness of the internal electrode, thickness of the second adhesive layer, thickness of the second insulating organic film The electrostatic chuck device according to any one of [1] to [6], wherein the sum of the thickness, the thickness of the intermediate layer, and the thickness of the ceramic layer is 200 μm or less.

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

1 is a cross-sectional view along the height direction of an electrostatic chuck device, showing a schematic configuration of the electrostatic chuck device of the present invention; FIG.

An electrostatic chuck device according to an embodiment to which the present invention is applied will be described below. In addition, in the drawings used in the following description, the dimensional ratios and the like of each component are not necessarily the same as the actual ones.
It should be noted that the present embodiment is specifically described for better understanding of the gist of the invention, and does not limit the invention unless otherwise specified.

[Electrostatic chuck device]
FIG. 1 shows a schematic configuration of the electrostatic chuck device of this embodiment, and 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. And prepare. 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, and a first adhesive layer 31. , a second adhesive layer 32 , a first insulating organic film 41 , a second insulating organic film 42 , an intermediate layer 50 and a 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 The internal 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 are laminated in this order.

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

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

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 sum of the thickness, the thickness of the intermediate layer 50, and the thickness of the ceramic layer 60 (the ceramic base layer 61 and the ceramic surface layer 62) (hereinafter referred to as "total thickness (1)") is 200 µm or less. is preferred, and 170 µm or less is more preferred. If the total thickness (1) is 200 μm or less, the electrostatic chuck device 1 is excellent in withstand voltage characteristics and plasma resistance, and as a result, is excellent in attracting force.

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, and the second insulating organic film 42 (hereinafter referred to as "total thickness (2)") is preferably 110 µm or less, more preferably 90 µm or less. If the total thickness (2) is 110 μm or less, the electrostatic chuck device 1 is excellent in withstand voltage characteristics and plasma resistance, and as a result, is excellent in attracting force.

The total thickness of the second adhesive layer 32 and the thickness of the second insulating organic film 42 (hereinafter referred to as "total thickness (3)") is preferably 50 µm or less, and preferably 40 µm. The following are more preferable. If the total thickness (2) is 50 μm or less, the electrostatic chuck device 1 is excellent in withstand voltage characteristics and plasma resistance, and as a result, is excellent in attracting force.

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

As shown in FIG. 1, the ceramic layer 60 is formed on the outer surface of the laminate 2 (the upper surface 2a of the laminate 2, the side surface (the surface along the thickness direction of the laminate 2, the first adhesive layer) of the laminate 2 through the intermediate layer 50. 31, 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. The layer 50 covers the entire outer surface of the laminate 2, and the ceramic layer 60 covers 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). is preferred.

As shown in FIG. 1, the ceramic layer 60 includes a ceramic base layer 61 and a ceramic surface layer 62 formed on an upper surface 61a of the ceramic base layer 61 (upper surface in the thickness direction of the ceramic base layer 61) and having unevenness. It is preferable to have

The sum of the thickness of the ceramic base layer 61, the thickness of the ceramic surface layer 62, the thickness of the intermediate layer 50, the thickness of the second adhesive layer 32, and the thickness of the second insulating organic film 42 (hereinafter referred to as "total thickness (4)”) is preferably 125 μm or less, more preferably 110 μm or less. If the total thickness (4) is 125 μm or less, the electrostatic chuck device 1 is excellent in withstand voltage characteristics and plasma resistance, and as a result, is excellent in attracting 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 . Also, the first internal electrode 21 and the second internal electrode 22 may be formed inside the second adhesive layer 32 as shown in FIG. The arrangement of the first internal electrodes 21 and the second internal electrodes 22 can be appropriately designed.

Since the first internal electrode 21 and the second internal electrode 22 are independent of each other, it is possible to apply not only voltages of the same polarity but also voltages of different polarities. 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 adsorb objects such as conductors, semiconductors and insulators. Alternatively, only the first internal electrode 21 may be provided as a single pole.

Other layer configurations of the electrostatic chuck device 1 of the present embodiment are not particularly limited as long as the ceramic layer 60 is laminated on at least the upper surface 42a of the second insulating organic film 42 via the intermediate layer 50. . For example, the substrate 10 shown in FIG. 1 may be omitted.

The substrate 10 is not particularly limited, but may be a ceramic substrate, a silicon carbide substrate, a metal substrate made of aluminum, stainless steel, or the like.

The internal electrode 20 is not particularly limited as long as it is made of a conductive material capable of exhibiting an electrostatic adsorption force when a voltage is applied. As the internal electrode 20, for example, thin films made of metals such as copper, aluminum, gold, silver, platinum, chromium, nickel, and tungsten, and thin films made of at least two metals selected from the above metals are preferably used. be done. Examples of such metal thin films include those formed by vapor deposition, plating, sputtering, etc., and those formed by applying and drying a conductive paste, and specifically, metal foils such as copper foils. be done.

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, when the second insulating organic film 42 is formed, the upper surface 42a of the second insulating organic film 42 is less likely to be uneven. 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 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 .

When voltages with different polarities are applied to the first internal electrode 21 and the second internal electrode 22, the distance between the adjacent first internal electrode 21 and the second internal electrode 22 (in the thickness direction of the internal electrode 20) is The distance in the vertical direction) is preferably 2 mm or less. If the distance between the first internal electrode 21 and the second internal electrode 22 is 2 mm or less, a sufficient electrostatic force is generated between the first internal electrode 21 and the second internal electrode 22, resulting in a sufficient adsorption force. occurs.

The distance from the internal electrode 20 to the object to be adsorbed, that is, the distance from the upper surface 21a of the first internal electrode 21 and the upper surface 22a of the second internal electrode 22 to the object to be adsorbed on the ceramic surface layer 62 (first 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, which are present on the upper surface 21a of the internal electrode 21 and the upper surface 22a of the second internal electrode 22. 62) is preferably between 50 μm and 125 μm. If the distance from the internal electrode 20 to the object to be adsorbed is 50 μm or more, a 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 of insulation can be ensured. On the other hand, if the distance from the internal electrode 20 to the object to be adsorbed is 125 μm or less, sufficient adsorption force is generated.

Examples of adhesives constituting the adhesive layer 30 include epoxy resins, phenolic resins, styrene-based block copolymers, polyamide resins, acrylonitrile-butadiene copolymers, polyester resins, polyimide resins, silicone resins, amine compounds, and bismaleimide compounds. An adhesive containing one or two or more resins selected from, for example, as a main component is used.

Epoxy resins include bisphenol type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, glycidyl ether type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, trihydroxyphenylmethane type epoxy resin, tetraglycidyl Bifunctional or polyfunctional epoxy resins such as phenolalkane type epoxy resin, naphthalene type epoxy resin, diglycidyldiphenylmethane type epoxy resin, and diglycidylbiphenyl type epoxy resin can be used. Among these, bisphenol type epoxy resins are preferred. Among bisphenol type epoxy resins, bisphenol A type epoxy resins are particularly preferred. In addition, when epoxy resin is the main component, curing agents and curing accelerators for epoxy resins such as imidazoles, tertiary amines, phenols, dicyandiamides, aromatic diamines, organic peroxides, etc. Agents can also be added.

Examples of phenol resins include alkylphenol resins, p-phenylphenol resins, novolac phenol resins such as bisphenol A-type phenol resins, resol phenol resins, and polyphenylparaphenol resins.

Styrene-based block copolymers include styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-propylene-styrene copolymer (SEPS), and the like. mentioned.

Although the thickness of the adhesive layer 30 (the first adhesive layer 31 and the second adhesive layer 32) is not particularly limited, it 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, the second adhesive layer 32) is 5 μm or more, it functions sufficiently 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 insulation between the internal electrodes 20 can be ensured without impairing the adsorption force. be able to.

Materials constituting the insulating organic film 40 are not particularly limited, and examples thereof include polyesters such as polyethylene terephthalate, polyolefins such as polyethylene, polyimide, polyamide, polyamideimide, polyethersulfone, polyphenylene sulfide, and polyetherketone. , polyetherimide, triacetyl cellulose, silicone rubber, polytetrafluoroethylene, and the like. Among these, polyesters, polyolefins, polyimides, silicone rubbers, polyetherimides, polyethersulfones, and polytetrafluoroethylenes are preferable, and polyimides are more preferable, because of their excellent insulating properties. As the polyimide film, for example, Kapton (trade name) manufactured by DuPont Toray, Upilex (trade name) manufactured by Ube Industries, 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. more preferred. If 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 is 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-based resins, epoxy-based resins, and acrylic-based resins.
The inorganic insulating resin is not particularly limited, and examples thereof include silane-based resins and silicone-based resins.

The intermediate layer 50 preferably contains polysilazane. Polysilazanes include, for example, those known in the art. Polysilazane may be organic polysilazane or inorganic polysilazane. These materials may be used singly or in combination of two or more.

The content of the inorganic filler in the intermediate layer 50 is preferably 100 to 300 parts by mass, more preferably 150 to 250 parts by mass with respect to 100 parts by mass of polysilazane. If the content of the inorganic filler in the intermediate layer 50 is within the above range, the inorganic filler particles can form irregularities on the surface of the resin film, which is the cured product of the intermediate layer 50. It is easy to bite into between the inorganic filler particles, and the thermal spray material can be strongly adhered to the surface of the resin film.

Although the inorganic filler is not particularly limited, it is preferably at least one selected from the group consisting of alumina, silica and yttria.
The inorganic filler is preferably at least one of spherical powder and amorphous powder.
The spherical powder means a spherical body obtained by rounding the corners of the powder particles. In addition, amorphous powders are those that do not have a constant shape, such as crushed, plate-like, scale-like, needle-like, and the like.

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

The fibrous filler is preferably at least one selected from the group consisting of vegetable fibers, inorganic fibers and fibrous organic resins.
Pulp etc. are mentioned as a vegetable fiber.
Examples of inorganic fibers include fibers made of alumina.
Examples of fiberized organic resins include fibers made of aramid, Teflon (registered trademark), and the like.

The inorganic filler is preferably used in combination with a fibrous filler, and the total content of the inorganic filler and the fibrous filler with respect to the entire intermediate layer 50 (100% by volume) is 10% by volume to 80% by volume. is preferred. 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 to 40 μm, more preferably 5 μm to 20 μm. When the thickness of the intermediate layer 50 is 1 μm or more, the intermediate layer 50 is not locally thinned, and the ceramic layer 60 can be uniformly formed on the intermediate layer 50 by thermal spraying. On the other hand, when the thickness of the intermediate layer 50 is 40 μm or less, sufficient adsorption force is generated.

Materials constituting the ceramic layer 60 are not particularly limited, and examples thereof include boron nitride, aluminum nitride, zirconium oxide, silicon oxide, tin oxide, indium oxide, quartz glass, soda glass, lead glass, borosilicate glass, and zirconium nitride. , titanium oxide and the like are used. These materials may be used singly or in combination of two or more.
These materials are preferably powders with an average particle size of 1 μm to 25 μm. By using such powder, the voids in the ceramic layer 60 can be reduced and the withstand voltage of the ceramic layer 60 can be improved.

The thickness of the ceramic base layer 61 is preferably 10 μm to 80 μm, more preferably 40 μm to 60 μm. If the ceramic base layer 61 has a thickness of 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, a sufficient adsorption force is generated.

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

By polishing the surface of the ceramic surface layer 62, the adsorption force can be improved, and the unevenness of the surface can be adjusted as the surface roughness Ra.
Here, the surface roughness Ra means a value measured by the method specified in JIS B0601-1994.

The surface roughness Ra of the ceramic surface layer 62 is preferably 0.05 μm to 0.5 μm. If the surface roughness Ra of the ceramic surface layer 62 is within the above range, the adsorbed body can be adsorbed satisfactorily. As the surface roughness Ra of the ceramics surface layer 62 increases, the contact area between the object to be adsorbed and the ceramics surface layer 62 decreases, so the adsorption force also decreases.

In the electrostatic chuck device 1 of the present embodiment described above, the plurality of internal electrodes 20, the insulating organic films 40 provided on both sides in the thickness direction of the internal electrodes 20, and at least the internal electrodes 20 and the insulating and a ceramic layer 60 laminated via an intermediate layer 50 on the upper surface 2 a in the thickness direction of the laminate 2 including the organic film 40 . Therefore, plasma resistance and voltage resistance are improved at least on the upper surface 2a side in the thickness direction of the laminate 2, and abnormal discharge during use can be suppressed. Therefore, the electrostatic chuck device 1 of this embodiment is also excellent in attractability.

In the electrostatic chuck device 1 of the present embodiment, if the ceramic layer 60 covers the entire outer surface of the laminate 2 via the intermediate layer 50, the plasma resistance is improved on the upper surface 2a side and the side surface 2b side of the laminate 2. And the voltage resistance is improved, and abnormal discharge during use can be suppressed. Therefore, the electrostatic chuck device 1 of the present embodiment is more excellent in attracting properties.

In the electrostatic chuck device 1 of the present embodiment, the ceramics layer 60 has the ceramics underlayer 61 and the ceramics surface layer 62 formed on the upper surface 61a of the ceramics underlayer 61 and having the unevenness. can be controlled to

In the electrostatic chuck device 1 of the present 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. A ceramic layer 60 can be uniformly formed on 50 .

In the electrostatic chuck device 1 of the present embodiment, the inorganic filler is at least one of spherical powder and irregular-shaped powder, so that the filling state in the resin in the intermediate layer 50 is uniform dispersion or closest packing. In addition, it is possible to improve the adhesion to the ceramic base layer 61 by designing the filler so that part of the filler is exposed from the resin.

In the electrostatic chuck device 1 of the present embodiment, the fibrous filler is at least one selected from the group consisting of vegetable fibers, inorganic fibers, and fibrous organic resins. The toughness is improved, the adhesion with the ceramic base layer 61 is improved by arranging the fibers on the surface of the intermediate layer 50, and the thermal expansion between the ceramic base layer 61 sandwiching the intermediate layer 50 and the insulating organic film 40 is reduced. It is possible to relax the strain due to the difference in index.

In the electrostatic chuck device 1 of the present embodiment, since the insulating organic film is a polyimide film, the voltage resistance is improved.

In the electrostatic chuck device 1 of the present embodiment, the inorganic filler made of spherical powder and irregular-shaped powder is at least one selected from the group consisting of alumina, silica and yttria. Improves voltage resistance.

[Manufacturing method of electrostatic chuck]
A method for manufacturing the electrostatic chuck device 1 of the present embodiment will be described with reference to FIG.
A metal such as copper is deposited on the surface 41a of the first insulating organic film 41 (upper surface in the thickness direction of the first insulating organic film 41) to form a metal thin film. After that, etching is performed to pattern the metal thin film into a predetermined 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 20a of the internal electrode 20 with the second adhesive layer 32 interposed therebetween.

Next, the first insulating organic film 41, the internal electrode 20, the second adhesive layer 32, and the second insulation are laminated so that the lower surface 41b of the first insulating organic film 41 faces the front surface 10a of the substrate 10. A laminate composed of the organic film 42 is bonded to the surface 10 a of the substrate 10 via the first adhesive layer 31 .

Next, an intermediate layer 50 is formed so as to cover the entire outer surface of the laminate 2 including the internal electrodes 20 and the insulating organic film 40 .
A method for forming the intermediate layer 50 is not particularly limited as long as the intermediate layer 50 can be formed so as to cover the entire outer surface of the laminate 2 . Examples of methods for forming the intermediate layer 50 include a bar coating method, a spin coating method, a spray coating method, and the like.

Next, a ceramic base layer 61 is formed so as to cover the entire outer surface of the intermediate layer 50 .
The method of forming the ceramics underlayer 61 includes, for example, a method of applying a slurry containing the material constituting the ceramics underlayer 61 to the entire outer surface of the intermediate layer 50 and sintering to form the ceramics underlayer 61, and a method of forming the ceramics underlayer 61. A method of forming the ceramic underlayer 61 by thermally spraying the material that constitutes 61 onto the entire outer surface of the intermediate layer 50 can be used.
Here, thermal spraying is a method of forming a film by heating and melting a material that will form a coating (ceramic base layer 61 in this embodiment) and then injecting it onto an 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 .
The method of forming the ceramics surface layer 62 includes, for example, masking the upper surface 61a of the ceramics underlayer 61 with a predetermined shape, and then thermally spraying the material that constitutes the ceramics surface layer 62 onto the upper surface 61a of the ceramics underlayer 61 to form the ceramics. A method of forming the surface layer 62, after thermally spraying 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, the ceramic surface layer 62 is scraped by blasting to obtain the ceramic surface layer 62. is formed into an uneven shape, and the like.

Through the steps described above, the electrostatic chuck device 1 of the present embodiment can be manufactured.

EXAMPLES The present invention will be described in more detail with reference to examples and comparative examples below, but the present invention is not limited to the following examples.

[Example 1]
As the first insulating organic film 41, one side of a 12.5 μm-thick polyimide film (trade name: Kapton, manufactured by Toray DuPont) was plated with copper to a thickness of 9 μm. After applying a photoresist to the surface of the copper foil, development processing was performed after pattern exposure, and unnecessary copper foil was removed by etching. After that, the photoresist was removed by washing the copper foil on the polyimide film, and the first internal electrode 21 and the second internal electrode 22 were formed. On the first internal electrode 21 and the second internal electrode 22, an insulating adhesive sheet semi-cured by drying and heating was laminated as the second adhesive layer 32. As shown in FIG. The insulating adhesive sheet contains 27 parts by mass of bismaleimide resin, 3 parts by mass of diaminosiloxane, 20 parts by mass of resol phenolic resin, 10 parts by mass of biphenyl epoxy resin, and 240 parts by mass of ethyl acrylate-butyl acrylate-acrylonitrile copolymer. , which was mixed and dissolved in an appropriate amount of tetrahydrofuran and formed into a sheet. Thereafter, a 12.5 μm-thick polyimide film (trade name: Kapton, manufactured by Toray DuPont) was adhered as the second insulating organic film 42, and a laminated body was obtained by heat treatment. The thickness of the second adhesive layer 32 after drying was 20 μm.

Further, the first adhesive layer 31 is formed on the surface of the first insulating organic film 41 in the laminate opposite to the surface on which the first internal electrode 21 and the second internal electrode 22 are formed. A sheet made of an insulating adhesive having the same composition as the semi-cured insulating adhesive sheet was laminated. After that, the laminated body was adhered to a substrate 10 made of aluminum and bonded by heat treatment. The thickness of the first adhesive layer 31 after drying was 10 μm.

Next, 100 parts by mass of polysilazane and 200 parts by mass of an inorganic filler made of alumina (average particle size: 3 μm) are mixed with butyl acetate as a diluent medium, and the inorganic filler is evenly dispersed using an ultrasonic disperser. A paint was prepared by

Next, the surface of the second insulating organic film 42 of the laminate adhered to the substrate 10 and the side surface of the laminate 2 were sprayed with the paint and then dried by heating to form the intermediate layer 50 . The thickness of the intermediate layer 50 after drying on the surface of the second insulating organic film 42 was 10 μm.

Next, alumina (Al ₂ O ₃ ) powder (average particle size: 8 μm) was sprayed onto the entire surface of the intermediate layer 50 by plasma spraying to form a ceramic underlayer 61 with a thickness of 50 μm.

Next, after masking the surface of the ceramic underlayer 61 in a predetermined shape, the alumina (Al ₂ O ₃ ) powder (average particle diameter: 8 μm) is thermally sprayed onto the surface of the ceramic underlayer 61 to obtain a thickness. A ceramic surface layer 62 having a thickness of 15 μm was formed.

Next, the attracting surface of the ceramic surface layer 62 for attracting the object to be attracted was subjected to surface grinding with a diamond whetstone to obtain the electrostatic chuck device of Example 1. FIG.
As a result of measuring the surface of the obtained electrostatic chuck device according to JIS B0601-1994, the surface roughness Ra was 0.3 μm.

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

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

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

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

[Comparative Example 3]
In Comparative Example 2, the thickness of the ceramic surface layer 62 was changed to 20 μm, the thickness of the ceramic base layer 61 to 80 μm, and the thickness of the intermediate layer 50 to 30 μm. An electric chuck device was obtained.

[Comparative Example 4]
Except that, in Comparative Example 3, alumina (Al ₂ O ₃ ) powder (average particle size: 8 μm) was thermally sprayed directly onto the surface of the second insulating organic film 42 without providing the intermediate layer 50 by a plasma thermal spraying method. An electrostatic chuck device of Comparative Example 4 was obtained in the same manner as in Comparative Example 3.

Table 1 shows the thickness of each layer in the electrostatic chuck devices obtained in Examples 1 to 3 and Comparative Examples 1 to 4 and their total values.

Next, using the electrostatic chuck devices obtained in Examples 1 to 3 and Comparative Examples 1 to 4, withstand voltage characteristics, adsorption force and plasma resistance were evaluated. Table 2 shows the results.

[Evaluation item]
<Withstand voltage characteristics>
The withstand voltage characteristic is obtained 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 to the electrostatic chuck device under vacuum (10 Pa) and holding for 2 minutes. It was evaluated by Visual observation was carried out for 2 minutes, and no change was evaluated as "acceptable", and dielectric breakdown between the electrodes or between the insulating organic film and the ceramic layer was evaluated as "disabled".

<Adsorption power>
As for the attraction force, a dummy wafer made of silicon is used as an object to be attracted, and is attracted to the surface of the electrostatic chuck device under vacuum (10 Pa or less). After applying the voltage, it was held for 30 seconds. Helium gas was flowed through the through-hole provided in the substrate 10 while the voltage was applied, and the leakage amount of the helium gas was measured while increasing the gas pressure. A case where the dummy wafer can be stably adsorbed at a gas pressure of 100 Torr was evaluated as "accepted", and a case where the dummy wafer could not be stably absorbed was evaluated as "failed". Stable adsorption means a state in which the wafer floats due to an increase in the helium gas pressure, and a phenomenon in which the amount of helium leakage increases rapidly does not occur.

<Plasma resistance>
Plasma resistance was evaluated by installing an electrostatic chuck device in a parallel plate type RIE device, and then measuring oxygen gas (10 sccm) and carbon tetrafluoride gas (40 sccm) under vacuum (20 Pa or less) with a high frequency power supply (output 250 W). was introduced, and changes in the surface state of the electrostatic chuck device after exposure for 24 hours were visually observed. A sample in which the ceramic layer remained on the entire surface was evaluated as "acceptable", and a sample in which the ceramic layer partially disappeared and the insulating organic film was exposed was evaluated as "disabled".

As is clear from Table 2, the electrostatic chuck devices obtained in Examples 1 to 3 are thin films having a distance of 200 μm or less from the surface 10a of the substrate 10 to the surface of the ceramic surface layer 62. , excellent withstand voltage characteristics and plasma resistance, and as a result, excellent adsorptive power was confirmed.

On the other hand, the electrostatic chuck device obtained in Comparative Example 1 did not have sufficient plasma resistance because the ceramic underlayer 61 was thin. It was confirmed that the electrostatic chuck devices obtained in Comparative Examples 2 and 3 were inferior in attracting force because the distance from the surface 10a of the substrate 10 to the surface of the ceramic surface layer 62 exceeded 200 μm.
In addition, since the electrostatic chuck device obtained in Comparative Example 4 does not have the intermediate layer 50, the ceramic thermal spray material does not sufficiently adhere to the surface of the second insulating organic film 42, resulting in plasma resistance. confirmed to be inferior.

According to the electrostatic chuck device of the present invention, the ceramic layer is laminated on the upper surface in the thickness direction of the laminate including the internal electrodes and the insulating organic films provided on both sides in the thickness direction, with the intermediate layer interposed therebetween. As a result, a high adsorption force can be obtained while having excellent plasma resistance and withstand voltage characteristics. Therefore, according to the electrostatic chuck device of the present invention, it is possible to stably electrostatically attract and hold a conductor such as a wafer for a dry etching device or a semiconductor in a semiconductor manufacturing process.

1 electrostatic chuck device 2 laminate 10 substrate 20 internal electrode 21 first internal electrode 22 second internal electrode 30 adhesive layer 31 first adhesive layer 32 second adhesive layer 40 insulating organic film 41 second First insulating organic film 42 Second insulating organic film 50 Intermediate layer 60 Ceramic layer 61 Ceramic base layer 62 Ceramic surface layer

Claims (7)

a plurality of internal electrodes; insulating organic films provided on both sides of the internal electrodes in the thickness direction; and a ceramic layer laminated through
The electrostatic chuck device, wherein the intermediate layer 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. 2. The electrostatic chuck device according to claim 1, wherein the inorganic filler is at least one of spherical powder and amorphous powder. 3. The electrostatic chuck device according to claim 2, wherein said spherical powder and said amorphous powder are at least one selected from the group consisting of alumina, silica and yttria. The static filler according to any one of claims 1 to 3, wherein the fibrous filler is at least one selected from the group consisting of vegetable fibers, inorganic fibers and fibrous organic resins. Electric chuck device. 2. The electrostatic chuck device according to claim 1, wherein the ceramic layer has an underlying layer and a surface layer having unevenness formed on the upper surface of the underlying layer. The electrostatic chuck device according to any one of claims 1 to 5, wherein the insulating organic film is a polyimide film. The insulating organic film includes a first insulating organic film provided on the lower surface side of the internal electrode in the thickness direction and a second insulating organic film provided on the upper surface side of the internal electrode in the thickness direction. Consists of
A first adhesive layer is provided on the surface of the first insulating organic film opposite to the internal electrode,
A second adhesive layer is provided between the first insulating organic film and the second insulating organic film and the internal electrode provided on the upper surface side of the first insulating organic film in the thickness direction. provided,
Thickness of the first adhesive layer, thickness of the first insulating organic film, thickness of the internal electrode, thickness of the second adhesive layer, thickness of the second insulating organic film The electrostatic chuck device according to any one of claims 1 to 6, wherein the sum of the thickness, the thickness of the intermediate layer, and the thickness of the ceramic layer is 200 µm or less.

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