Kyocera Corporation

Saburo Nagano

Yasunori Kawanabe

Kazuhiro Kuchimachi

Hironori Inoue

Kenji Kitazawa

Yoshinori Matsunaga

Hiroshi Aida

Koichi Nagasaki

Yuji Iino

Tetsuya Ogushi

Gentaro Kaji

Hiromi Imura

Akihiro Kukita

A wafer holding member comprises a ceramic base body and a heating resistor, an electrostatic adhesion electrode or a plasma generation electrode embedded in the base body. The wafer holding member exhibits reduced thermal expansion and greater corrosion resistance against halogenic gases. The heating resistor is made of a mixture containing 90 to 99 wt % of at least one of W, Mo, WC, TiC and TiN (the first component), and 1 to 10 wt % of AlN (the second component), the electrostatic adhesion electrode is made of a mixture containing 50 to 99 wt % of said first component, and 1 to 50 wt % of said second component, and the plasma generation electrode is made of a mixture containing 80 to 99 wt % of said first component, and 1 to 20 wt % of said second component. When heating resistors are used, the ceramic base body can include a plurality of heating resistors embedded in the base body and energized successively, with the ratio of the resistance value of the heating resistor numbered m to the resistance value of the heating resistor numbered m-1 is in a range of 1.5 to 4. The ceramic holding member can comprise a corrosion-resistant member made of an aluminum nitride based sintered body and more particularly, at least the mounting surface that holds the wafer is made of 99 wt % or more AlN and 1500 ppm or less of silicon.

Wafer holding member

A wafer support member comprises a base made of ceramics with thickness of 3 mm or more, a metallic electrode plate with thickness of 0.5 mm or more bonded onto the base, and an attraction surface composed of an aluminum nitride film with thickness of 0.01 to 0.5 mm coated on the surface of the electrode plate. The electrode plate functions as a plasma generating electrode when high frequency voltage is applied to the electrode plate and as an electrostatic attraction electrode when direct-current high voltage is applied to the electrode plate. Also, a wafer holding device for holding a wafer such as semiconductor wafer and glass substrate for liquid crystal is disclosed. The wafer holding device comprises a base body of aluminum nitride sintered body containing resistance heating elements therein. Lead terminals for feeding power to the resistance heating elements are formed in the lower surface of the base body. In one feature, at least the lead terminals and junction thereof are coated with a ceramic film composed of any one of silicon carbide, silicon nitride, sialon, and aluminum nitride. In another feature, the base body has a flat surface for forming an attraction surface, an outer circumference and penetration holes. Each of the penetration holes opens in the flat surface, and has an inner wall. An aluminum nitride film covers the flat surface, the outer circumference, and the inner wall of each of the penetration holes.

Wafer support member

Disclosure relates to the method for improving the heat absorption characteristic of a wafer holding member made of aluminum nitride during indirect heating and the method for preventing electrostatic adhesion. To establish the former method, the wafer holding member comprises an aluminum nitride based sintered body containing Er.sub.2 O.sub.3 as a sintering aid and silicon in the range of more than 200 ppm to 500 ppm or less and having a thermal conductivity of 150 W/m.k or more, and further comprises a holding base body made of an aluminum nitride based sintered body.

Disclosed is a process for the preparation of a composite metal oxide superconductor, in which a composite metal oxide composition comprising Bi, Pb, Sr, Ca and Cu and further containing an alkali metal at a specific ratio is used as the starting material, and this composite metal oxide composition is molded and fired. According to this process, precipitation of the 80 K phase and other impurities is controlled, and a superconductor containing a large quantity of the 110 K phase and a high critical temperature is obtained.

Bi-Pb-Sr-Ca-Cu oxide superconductor containing alkali metal and process

Disclosed is an oxide superconductor, wherein at least the surface layer has a chemical composition represented by the following formula:

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Kokubu, Japan

Saburo Nagano