JPH10209256A - Electrostatic chuck device and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the thermal conductivity of an electrostatic chuck device and, at the same time, to improve the replaceability of an insulating film having an adsorbing surface, by laminating electrode layers and the insulating film on a ceramic insulating plate through adhesive layers. SOLUTION: In an electrostatic chuck device, a first adhesive layer 2a having a high insulating property, a ceramic insulating plate 7, a second adhesive layer 2b, electrode layers 3 composed of vapor-deposited or plated metallic films, and an insulating film 4 are successively formed on a metallic substrate 1. The electrode layers 3 are provided so as to generate polarized charges on the adsorbing surface of the insulating film 4 and the adhesive layers 2a and 2b are formed of a thermosetting or thermoplastic adhesive, because the layers 2a and 2b must have strong adhesive forces and electrical characteristics against the insulating plate and metallic substrate comprising the insulating film 4, the electrode layers 3, and the ceramic insulating plate 7, and metallic substrate 1. Therefore, the thermal conductivity of the adhesive layers 2a and 2b can be improved as the thin film and, at the same time, the workability of the replacing work of the insulating film 4 can be improved when the film 4 is fatigued, because the thicknesses of the layers 2a and 2b are reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic chuck device, such as a semiconductor integrated circuit manufacturing apparatus, capable of holding a conductive material such as a wafer in a vacuum. The present invention relates to an electrostatic chuck device in which an insulating film having an adhesive surface can be easily replaced and a method for manufacturing the same.

[0002]

2. Description of the Related Art In a process of processing a semiconductor wafer, it is necessary to fix and hold the semiconductor wafer at a predetermined portion of a processing machine. In particular, in producing an integrated circuit in which a fine pattern is drawn on a semiconductor wafer to form a large number of semiconductor elements, it is necessary to reliably hold the semiconductor wafer on a flat surface. Conventionally, as a means for holding a semiconductor wafer, a mechanical type, a vacuum type (using a pressure difference of a fluid) and an electric type chuck device are used. Among these, the electric chuck device, that is, the electrostatic chuck device, has the advantages that it can be fixed with good adhesion even when the semiconductor wafer is not flat, and that it is easy to handle and easy to use even in a vacuum. I have. By the way, when a beam particle or the like is hit by injection during processing of a semiconductor wafer,
Thermal energy is generated on the semiconductor wafer, but if the generated thermal energy cannot be easily released, it causes local expansion and deformation of the semiconductor wafer. Therefore, it is necessary to dissipate the heat generated during processing to the metal substrate side and to make the temperature distribution on the semiconductor wafer uniform. Therefore, electrostatic chuck devices used for these applications include:
It is desired as a function that it is securely held at a predetermined portion and has high thermal conductivity.

An example of a conventional electrostatic chuck device, for example,
FIG. 2 disclosed in Japanese Patent Publication No. 5-87177 is a schematic cross-sectional view of an example of a conventional electrostatic chuck device, and a temperature control space 6 for controlling the temperature of a metal base 1 through constant temperature water or the like. Is provided. An electrode layer 3b for providing an electrostatic chuck function and an insulating film 4a are provided on the metal substrate 1 via an adhesive layer 2, and a semiconductor wafer 5 is attracted to the insulating film 4a. The electrode layer 3
An insulating film 4b is provided between the electrode layer and the metal base via the adhesive layer 2 so as to prevent an electrical short between the metal base 1 and the metal base 1 from occurring. FIG. 3 shows an example of a conventional electrostatic chuck device, for example, JP-A-8-1485.
FIG. 49 is a schematic sectional view of the one disclosed in 49. The metal substrate 1 is provided with the above-mentioned temperature control space 6. An insulating adhesive layer 2 is formed on a metal substrate 1, an electrode layer 3a made of a metal deposition film or a plating film is provided thereon, and an insulating film 4 is provided thereon. The semiconductor wafer 5 is attracted to this. In the above-described electrostatic chuck device, copper, aluminum, tin, or the like is deposited or plated to a thickness of 500 Å to 10 μm as an electrode material of the electrode layer 3a. 18μm) or 1o
A copper foil of z (about 35 μm) is used.

[0004]

In the conventional electrostatic chuck device shown in FIG. 2, insulating films 4a and 4b are interposed to ensure insulation between the semiconductor wafer 5, the electrode layer 3b and the metal substrate 1. The function of adjusting the temperature of the semiconductor wafer 5 was poor. In short, there is a problem that the cooling function of the substrate for the semiconductor wafer does not work sufficiently.
Further, in the electrostatic chuck device of FIG. 2, irregularities corresponding to the thickness of the electrode layer are generated between a portion where the electrode is present and a portion where the electrode is not present on the suction surface, and the concave portion is in contact with the semiconductor wafer. A phenomenon occurred in which a space was formed between the two and heat conduction was locally deteriorated. This phenomenon is remarkable in the outer peripheral portion where the cooling gas is not used, and there is a problem that a so-called insulating width portion is in a floating state and thermal conductivity in a vacuum is deteriorated. In FIG. 3, the total thickness of the insulating film, the electrode layer and the adhesive layer is smaller than that in FIG. 2, and the thermal conductivity is improved. However,
In order to ensure sufficient insulation, the adhesive layer needs to be at least 40 to 50 μm or more, and the thermal conductivity has not been sufficient yet. In addition, when the electrostatic chuck device of FIGS. 2 and 3 is used many times, the insulating film having the suction surface becomes fatigued and needs to be replaced. When a thermosetting adhesive is used, it has been desired to simplify the step of cleaning the insoluble adhesive layer.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an electrostatic chuck device which improves the thermal conductivity of the electrostatic chuck device and has excellent exchangeability of an insulating film having a suction surface, and a method of manufacturing the same. It is in.

[0006]

SUMMARY OF THE INVENTION The present invention provides a first adhesive layer, a ceramic insulating plate, a second adhesive layer, an electrode layer made of a metal deposition film or a plating film on a metal substrate, and an insulating material. On one surface of the electrostatic chuck device and the insulating film, wherein the film is sequentially laminated, an electrode layer composed of a metal vapor deposition film or a plating film is formed, and a photoresist layer is provided on the surface of the electrode layer. Performing a pattern exposure, developing, and performing an etching process; providing a second adhesive layer on the etched electrode layer surface to form a laminate sheet; An electrostatic chuck device comprising: a step of bonding to a metal substrate via an adhesive layer; and a step of bonding an insulating plate made of ceramic and the adhesive sheet via a second adhesive layer. It is a manufacturing method.

Hereinafter, the present invention will be described in detail. FIG. 1 is a schematic sectional view of an example of the electrostatic chuck device of the present invention. In the electrostatic chuck device of the present invention, a first adhesive layer 2a having excellent insulating properties is formed on a metal substrate 1, an insulating plate 7 made of ceramic is provided thereon, and a second adhesive layer 2a is provided thereon.
Is formed, an electrode layer 3 made of a metal deposition film or a plating film is provided thereon, and an insulating film 4 is further provided thereon. The electrode layer is for generating a polarization charge on the adsorption surface of the insulating film. 5 is a semiconductor wafer, 6 is a space for temperature adjustment,
Reference numeral 8 denotes a laminate sheet including an insulating film, an electrode layer, and an adhesive layer.

The metal used for the deposition and plating of the electrode layer may be any material that can be easily deposited or plated with copper, aluminum, tin, nickel, chromium silver, etc., and that can easily form a pattern by wet etching or the like. Any metal may be used, and there is no particular limitation as long as stable conductivity and workability can be obtained. The thickness of the deposited film or the plated film may be in the range of 300 Å to 10 μm. For highly reactive materials such as aluminum, 3
If the thickness is less than 00 Å, it is difficult to maintain stable conductivity at the same time as the workability is poor.
It is preferably 300 Å or more. In consideration of workability and the like, the thickness of the deposited film or the plated film is more preferably in the range of 500 Å to 5 μm.

The film used for the insulating film is preferably an insulating film having a heat resistance of 150 ° C. or more, and particularly preferably a polyimide film, in consideration of electric characteristics such as ε, tan δ, withstand voltage and heat resistance. . Fifteen
Examples of the insulating film having heat resistance of 0 ° C. or higher include fluororesin (fluoroethylene-propylene copolymer or the like), polyethersulfone, polyetherketone, cellulose triacetate, silicone rubber, polyimide, and the like. As a polyimide film,
For example, those marketed under the trade names such as Kapton (manufactured by Dupont Toray Co., Ltd.), Apical (manufactured by Kanebuchi Chemical Industry Co., Ltd.), and Upilex (manufactured by Ube Industries) are listed. The thickness of the insulating film is preferably in the range of 20 to 75 μm. The thickness is preferably thinner in consideration of thermal conductivity and adsorption force, but particularly preferably 40 to 60 μm in consideration of mechanical strength, withstand voltage and durability (fatigue resistance).

According to the present invention, an insulating plate made of ceramic is laminated on a metal base via a first adhesive layer. The ceramic is required to have excellent insulation and thermal conductivity and have solvent resistance, specifically, alumina, aluminum nitride,
Silicon nitride, silicon carbide, zirconia, glass and the like are preferable, and those having a smooth surface are used. The thickness of the ceramic is preferably in the range of 0.5 to 8 mm, more preferably 0.5 to 4 mm in consideration of releasing heat from the surface to be attracted and durability. Generally, the electrostatic chuck device cools the semiconductor wafer by flowing He gas. Therefore, the insulating plate made of the ceramic has H
It is preferable to provide an e gas hole.

Next, as an adhesive layer for adhering these materials to the metal substrate, the adhesive force, electric characteristics, and heat resistance to the four members of an insulating film, an electrode layer, an insulating plate made of ceramic and a metal substrate are considered. It needs to be good, and thermosetting adhesives and thermoplastic adhesives are used. Examples of the resin constituting the adhesive used in the present invention, for example, epoxy-based, polyimide-based, modified polyamide-based, rubber-based, polyamideimide-based, modified polyester-based adhesives are effective, each alone or It can be used as a mixture.

The thermal conductivity of the insulating film and the adhesive layer used in the electrostatic chuck device of the present invention does not change since the same material as in the prior art is used. By using the insulating plate, the second adhesive layer and the first adhesive layer for bonding the insulating film and the insulating plate made of ceramic can be made thinner as compared with the technique disclosed in FIG. This makes it possible to quickly release the heat received on the adsorption surface to the insulating plate made of ceramic and from the insulating plate to the metal base. In addition, since the thickness of the adhesive layer is reduced, the step of cleaning the surface of the adhesive layer at the time of replacing the insulating film is facilitated, and the replacement workability is improved.

Next, a method for manufacturing the electrostatic chuck device of the present invention will be described. First, a metal film is formed on one surface of an insulating film by a vapor deposition method or a plating method, and a photoresist layer is formed on the metal film surface. The photoresist layer may be formed by applying a liquid resist and drying, or may be formed by bonding a photoresist film (dry film) by thermocompression bonding. Then, pattern exposure,
Perform development, etching, washing, resist stripping and drying,
An electrode layer having a predetermined shape is formed. These operations may be performed using a known method for forming a photoresist pattern. A second adhesive coating liquid is applied to the metal surface of the etched electrode layer, and dried to form a second adhesive layer, thereby producing a laminate sheet. The adhesive layer is preferably made thin so that the heat received by the surface to be attracted of the insulating film is easily released to the insulating plate made of ceramic.
The formed laminate sheet is punched according to the shape of the insulating plate made of ceramic, if necessary, to produce a laminate sheet for an electrostatic chuck device.

Next, the insulating plate made of the ceramic is bonded to the metal substrate via the first adhesive layer. The adhesive layer described above is preferably used, and it is preferable to make the adhesive layer thin so that the heat of the insulating plate made of ceramic can be easily released to the metal substrate. Next, the insulating plate made of ceramic and the laminate sheet are bonded via a second adhesive layer.
When a thermosetting adhesive is used, appropriate heating, semi-curing, and curing are performed as necessary. As described above, the electrostatic chuck device of the present invention can be manufactured. When the insulating film on the suction surface is fatigued, the fatigued insulating film, the electrode layer, and the second adhesive layer are peeled off, and a new laminate sheet is bonded. In the above process, the fatigued insulating film can be easily replaced.

Hereinafter, the present invention will be described in more detail with reference to examples.

【Example】

Example 1 Aluminum was vapor-deposited to a thickness of 800 Å on an insulating film made of a polyimide film (trade name: Kapton, manufactured by Dupont Toray) having a thickness of 50 μm, and a negative photosensitive film (trade name: OZATEC- manufactured by Hoechst) was deposited.
T538), and then exposure-development-etching-
Through a washing-drying process, an electrode layer having a predetermined shape was formed. The development was carried out by spraying a 1% aqueous solution of sodium carbonate, the etching was carried out by spraying ferrous chloride, ferric chloride and an aqueous solution of hydrochloric acid, and ion-exchanged water was used for washing. Next, an adhesive having the following composition is applied to the electrode layer surface of the polyimide film so that the thickness after drying becomes 30 μm, and dried at 150 ° C. for 5 minutes to form a second adhesive layer. Then, a laminate sheet was prepared. Parts indicate parts by weight. Next, the first adhesive layer paint is applied on the aluminum metal substrate so that the thickness after drying becomes 30 μm,
The first adhesive layer was formed by drying at 150 ° C. for 5 minutes and bonded to a 3 mm-thick alumina ceramic insulating plate (trade name: AL-13, manufactured by Toshiba Ceramics Co., Ltd.). At this time,
The metal base and the insulating plate have a through hole in the thickness direction,
The metal substrate was configured such that a voltage could be applied between the electrode layer and the metal substrate by passing a conductive member into the through hole. Next, after the insulating plate and the second adhesive layer surface of the laminate sheet are bonded together, a step cure process at 80 ° C. to 150 ° C. is performed for 5 hours to bond, and the electrostatic chuck having a diameter of 8 inches according to the present invention. An electrostatic chuck device having a surface was manufactured.

Example 2 Instead of the alumina ceramic insulating plate used in Example 1, a silicon nitride ceramic insulating plate having a thickness of 2 mm (trade name: TSN-03, manufactured by Toshiba Ceramics Co., Ltd.) was used. An electrostatic chuck device having an electrostatic chuck surface having a diameter of 8 inches according to the present invention was manufactured in the same manner as in Example 1 except that an Angstrom copper plating film was used.

Comparative Example 1 The adhesive used in Example 1 was applied to the insulating polyimide film having a thickness of 50 μm used in Example 1 so that the thickness of the adhesive layer after drying became 10 μm. , 15
After drying at 0 ° C. for 5 minutes, a copper foil having a thickness of 23 μm was stuck and a step cure treatment at 80 ° C. to 150 ° C. was performed. An electrode having a predetermined shape was formed on the copper foil surface of the polyimide film using the negative photosensitive film used in Example 1 in the same manner as in Example 1. On the other hand, on one surface of the other polyimide film, the adhesive paint was applied so that the thickness of the adhesive layer after drying became 10 μm, and 150 ° C.
For 5 minutes to form an adhesive layer. The adhesive layer was bonded to the electrode surface of the polyimide film on which the electrodes were formed. Next, an adhesive paint was applied to one surface of the laminated polyimide film so that the thickness after drying became 20 μm, and the coating was dried at 150 ° C. for 5 minutes, and then bonded to the metal substrate used in Example 1. 80 ° C to 150 ° C
By performing the step curing process described above, an electrostatic chuck device having an electrostatic chuck surface having a diameter of 8 inches and having a structure shown in FIG. 2 was manufactured.

Comparative Example 2 The adhesive paint used in Example 1 was applied to the electrode layer surface of a polyimide film having an aluminum vapor-deposited electrode layer formed on one surface in the same manner as in Example 1 so that the thickness after drying was 20 μm. It was applied and dried at 150 ° C. for 5 minutes. Further, a second coating was performed on the adhesive layer surface to form an adhesive layer having a thickness of 40 μm. Next, after bonding the metal substrate used in Example 1 and the adhesive layer surface of the polyimide film on which the electrode layer was formed, the surface of the electrostatic chuck having a diameter of 8 inches was subjected to a step curing process at 80 ° C. to 150 ° C. And an electrostatic chuck device having a structure shown in FIG. 3 was manufactured.

The surface temperature of the semiconductor wafer was measured using the electrostatic chuck devices obtained in the above Examples and Comparative Examples, and the results are shown in Table 1. (Measurement Method) A temperature measurement plate was attached on a semiconductor wafer, and discharged for 1 minute under the following etching conditions, and the temperatures at the center, edge, and middle of the wafer were measured. In addition, the applied voltage of the electrostatic attraction was 2.0 KV. (Etching conditions) High frequency output = 1400 (W), chamber vacuum degree = 40 (mT), filling gas in chamber:
CHF ₃ / CO = 45/155 (sccm), He gas flowing in the gap when the wafer and the electrostatic chuck surface are brought into contact =
10 (Torr), chamber temperature (top / side / bottom) = 60/60/20 (° C.)

[0020]

[Table 1]

As is apparent from the results shown in Table 1, the electrostatic chuck device of the present invention has a low in-plane temperature at the edge portion of the semiconductor wafer and a large heat radiation effect. Comparative Example 2 of the electrostatic chuck device of the present invention because the insulating property is ensured
The adhesive layer can be made thinner than this, and the heat radiation effect is large, and at the same time, the adhesive layer on the top of the ceramic insulating plate is easily cleaned when replacing the insulating film, so the workability at the time of replacement is greatly improved .

[0022]

According to the electrostatic chuck device of the present invention, the electrode layer and the insulating film are laminated on the ceramic insulating plate via the adhesive layer as described above. It becomes an adhesive layer. Therefore, the heat conductivity can be improved, and at the same time, the exchanging workability when the insulating film becomes fatigued is greatly improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of an example of the electrostatic chuck device of the present invention.

FIG. 2 is a cross-sectional view of an example of a conventional electrostatic chuck device.

FIG. 3 is a cross-sectional view of an example of a conventional electrostatic chuck device.

[Brief description of reference numerals]

1. Metal base, 2. Adhesive layer, 2a First adhesive layer, 2b Second adhesive layer, 3, 3a, 3b
..Electrode layer, 4,4a, 4b..Insulating film, 5
..Semiconductor wafer, 6..Temperature adjustment space, 7..Insulating plate, 8..Laminate sheet

Claims (3)

[Claims] A first adhesive layer, an insulating plate made of ceramic, a second adhesive layer, an electrode layer made of a metal deposition film or a plating film, and an insulating film are sequentially laminated on a metal substrate. An electrostatic chuck device characterized by the above-mentioned. 2. The electrostatic chuck device according to claim 1, wherein an electrode layer made of a metal deposition film or a plating film is formed on one surface of an insulating film. 3. An electrode layer made of a metal deposition film or a plating film is formed on one surface of an insulating film, a photoresist layer is provided on the surface of the electrode layer, pattern exposure is performed, development is performed, and etching is performed. Performing, providing a second adhesive layer on the etched electrode layer surface to form a laminate sheet, and bonding an insulating plate made of ceramic to the metal substrate via the first adhesive layer. And a step of adhering the insulating sheet made of ceramic and the adhesive sheet via a second adhesive layer.