Abstract: A bonded body consisting of a ceramic member and a metal composite member of which bonding layer is less likely to be eroded by plasma is provided. The bonded body comprises the ceramic member that has two opposing main surfaces with a first metal layer provided on one of the main surfaces, the metal composite member that has two opposing main surfaces with a second metal layer provided on one of the main surfaces, and a brazing material layer that joins the first metal layer and the second metal layer, wherein the brazing material layer has an outer circumferential surface that has a depression formed therein at middle position in the direction of thickness thereof, with the depression having width at least one third the thickness of the brazing material layer.

Abstract: An electrostatic chuck having a good soaking feature and allowing a wafer to reach a saturation temperature quickly is provided. The chuck, which has a platy body with a pair of main surfaces, one main surface being used as a mounting surface for mounting a wafer, and an attracting electrode on the other main surface or inside the body, has at least one gas introducing through hole formed so as to pass through the body, a gas flow path formed in the mounting surface by a plurality of mutually separated protrusions and formed so as to communicate with the through hole, and an annular wall portion formed on the outer periphery of the body, characterized in that the planar shape of each of the above protrusions consists of four sides and arc-shaped portions connecting the four sides, and the above protrusions are uniformly arranged on the mounting surface.

Abstract: A composite material according to the present invention, is composed of SiC, SiO2, at least one out of Al and Si, with He leak rate of 1.3×10?10 Pa·m3/sec or below, thereby providing a composite material, which has a higher vacuum air-tightness, an excellent thermal conductivity, an adjustable coefficient of thermal expansion, small variation in strength and higher reliability, and a method for manufacturing the composite material, and a wafer holding member including the composite material.

Abstract: An electrostatic chuck having a good soaking feature and allowing a wafer to reach a saturation temperature in a short time. The electrostatic chuck (1), which has a platy body (8) provided with a pair of main surfaces, one main surface being used as a mounting surface (8a) for mounting a wafer (W), and an attracting electrode (6) provided on the other main surface or inside the platy body, comprises at least one gas introducing through hole (5) formed so as to pass through the platy body, a gas flow path (8d) formed in the mounting surface by a plurality of mutually separated protrusions (8b) and formed so as to communicate with the above through hole, and an annular wall portion (8c) formed on the outer periphery of the platy body, characterized in that the planar shape of each of the above protrusions consists of four sides and arc-shaped portions connecting the four sides, and the above protrusions are uniformly arranged on the above mounting surface.

Abstract: A bonded body consisting of a ceramic member and a metal composite member of which bonding layer is less likely to be eroded by plasma is provided. The bonded body comprises the ceramic member that has two opposing main surfaces with a first metal layer provided on one of the main surfaces, the metal composite member that has two opposing main surfaces with a second metal layer provided on one of the main surfaces, and a brazing material layer that joins the first metal layer and the second metal layer, wherein the brazing material layer has an outer circumferential surface that has a depression formed therein at middle position in the direction of thickness thereof, with the depression having width at least one third the thickness of the brazing material layer.

Abstract: A composite material according to the present invention, is composed of SiC, SiO2, at least one out of Al and Si, with He leak rate of 1.3×10?10 Pa·m3/sec or below, thereby providing a composite material, which has a higher vacuum air-tightness, an excellent thermal conductivity, an adjustable coefficient of thermal expansion, small variation in strength and higher reliability, and a method for manufacturing the composite material, and a wafer holding member including the composite material.

Abstract: There is provided a bonding heater used to package a semiconductor chip on a multilayer substrate, which has adaptability to various chip sizes, with an excellent maintenance characteristics, with undesirable displacement of the chip at the time of mounting a semiconductor chip being made as small as possible and also with a temperature rise time to a desired temperature being shortened. This bonding heater is constituted by a ceramic tool for pressing an object to be heated, a ceramic heater for heating the tool, a heat insulating member for transferring heat generated by the ceramic heater mainly to the tool side and a holder for integrating these members and connecting these members to another member, and the tool, ceramic heater, heat insulating member and holder are detachably bonded.

Abstract: There is provided a bonding heater used to package a semiconductor chip on a multilayer substrate, which has adaptability to various chip sizes, with an excellent maintenance characteristics, with undesirable displacement of the chip at the time of mounting a semiconductor chip being made as small as possible and also with a temperature rise time to a desired temperature being shortened. This bonding heater is constituted by a ceramic tool for pressing an object to be heated, a ceramic heater for heating the tool, a heat insulating member for transferring heat generated by the ceramic heater mainly to the tool side and a holder for integrating these members and connecting these members to another member, and the tool, ceramic heater, heat insulating member and holder are detachably bonded.

Abstract: Disclosed is a silicon nitride sintered body comprising 85 to 99 mole % of .beta.-Si.sub.3 N.sub.4, 1 to 5 mole % as the oxide (M.sub.2 O.sub.3) of at least one compound of an element (M) selected from the group consisting of Sc, Vb, Er, Ho and Dy and less than 10 mole % of excessive oxygen (O.sub.2) based on the three components, wherein the excessive oxygen/M.sub.2 O.sub.3 molar ratio is lower than 2.

Abstract: Disclosed is a silicon nitride sintered body comprising 85 to 99 mol % of .beta.-Si.sub.3 N.sub.4, 1 to 5 mol % as the oxide (M.sub.2 O.sub.3) of at least one compound of an element (M) selected from the group consisting of Sc, Vb, Er, Ho and Dy and less than 10 mol % of excessive oxygen (O.sub.2) based on the three components, wherein the excessive oxygen/M.sub.2 O.sub.3 molar ratio is lower than 2.

Abstract: Disclosed is a process for the preparation of a silicon nitride sintered body, which comprises steps of (i) molding a composition comprising (a) 87 to 98% by weight of silicon nitride and (b) 2 to 13% by weight of a sintering aid comprising an oxide or nitride of aluminum or an element of the group IIIa of the Periodic Table and an inorganic oxide capable of forming a liquid phase component having a melting point lower than that of silicon nitride, the inorganic oxide being present in an amount of 1 to 7% by weight based on the composition, (ii) sintering the molded body in a nitrogen atmosphere at a temperature forming a liquid phase containing said liquid phase component having a low melting point, and (iii) heat-treating the resulting sintered body in a nitrogen atmosphere at a temperature higher than the sintering temperature to volatilize the liquid phase component having a low melting point from the liquid phase.

Abstract: Disclosed is a silicon nitride sintered body comprising 1 to 20% by weight as the oxide of a zirconium component and 1 to 10% by weight as the oxide of a yttrium component, with the balance being silicon nitride, in which the amount of excessive oxygen is 0 to 3% by weight based on the sintered body. This sintered body is obtained by sintering a starting material mixture comprising the above-mentioned three components in a nitrogen atomosphere controlled by SiO.sub.2 added to the stating material mixture or in a nitrogen atmosphere controlled by the co-presence of a mixture of metallic silicon and silica.

Abstract: Disclosed is a sintered body of a composition comprising (i) 80 to 99% by weight of Si.sub.3 N.sub.4, (ii) 1 to 20% by weight of oxides, nitrides and the like of Sr, W and a rare earth element as the main additive and (iii) an oxide, a nitride or the like of Al, Ti, Cr, Si or Mo as the auxiliary additive in an amount of up to 5 parts by weight per 100 parts by weight of the components (i) and (ii). This sintered body is excellent in oxidation resistance and mechanical strength at high temperatures.

Abstract: When a composite nitride obtained by nitriding a fine powder of an alloy comprising metallic silicon and a metal of the group IIIa of the Periodic Table is sintered, a highly homogeneous silicon nitride sintered body having a high strength can be obtained. This fine powder of the alloy and this composite nitride exert a function of promoting sintering of Si.sub.3 N.sub.4.

Abstract: Disclosed is a sintered ceramic body having a composition comprising (i) Si.sub.3 N.sub.4, (ii) a combination of an oxide of an element of the group IIIa of the Periodic Table having an ionic radius smaller than 0.97 .ANG. and an oxide of other element of the group IIIa of the Periodic Table, having an ionic radius larger than 0.97.degree. and (iii) an oxide or nitride of at least one of the following: (1) at least one element of group IIa of the Periodic Table; (2) Al; (3) Ti; (4) Cr; (5) Ga; (6) Zr; and (7) Si. This sintered silicon nitride body shows a high oxidation resistance when it is used for a long time at high temperatures, and the sintered body is excellent in the creep characteristics and flexural strength at high temperatures.