Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Disclosed is an oxide superconductor, wherein at least the surface layer has a chemical composition represented by the following formula:La.sub.x Sr.sub.y NbO.sub.zwherein0<x<1,0<y<1, and1<z<4,and has a critical temperature (Tc) higher than 100.degree. K.This superconducotr has a high critical temperature and is rendered superconducting by cooling with cheap liquefied nitrogen.This superconductor is prepared by a process comprising carrying out sputtering in an argon atmosphere by using one of NB and an La--Sr--Cu--O oxide as the substrate and the other as the target under such a temperature condition that substitution of Cu by Nb is caused, an quencing the formed film.

Abstract: A method of producing a dense sintered silicon carbide body, which is high in flexural strength, purity and strength at an elevated temperature, from polycarbosilanes is disclosed. This method comprises the following steps of:A. polymerizing organosilicon compounds to obtain insoluble and unmeltable polycarbosilane of which the melting or softening temperature lies higher than its thermal decomposition temperature;B. grinding this insoluble and unmeltable polycarbosilane to powder;C. decomposing this powder thermally in the range of 600.degree. to 2200.degree. C. in a nonoxidizing atmosphere to obtain silicon carbide;D. molding this silicon carbide powder; andE. sintering the thus molded body in a nonoxidizing atmosphere.

Abstract: A method of producing a sintered silicon carbide body high in density, flexural strength and purity at elevated temperatures from polycarbosilanes is disclosed. The method involves the following steps:(A) polymerizing organosilicon compounds to yield specific polycarbosilanes which are insoluble in solvents and unmeltable i.e. the polycarbosilanes being higher in melting temperature or in softening temperature than in thermal decomposition temperature;(B) pulverizing the insoluble and unmeltable polycarbosilanes so as to form a powder;(C) applying heat with or without the use of pressure to the powder charged into a hot press mold in a nonoxidizing atmosphere to thereby decompose the same thermally into silicon carbide and sintering the silicon carbide under pressure.