Abstract: A sputtering target which is made of an alumina sintered body having a purity of not less than 99.99% by mass %, a relative density of not less than 98%, and an average grain size of less than 5 ?m or is made of an alumina sintered body having a purity of not less than 99.999% by mass % and a relative density of not less than 98%. A sputtered film having an excellent insulation resistance and an excellent homogeneity can be obtained by using the sputtering target.

Abstract: A sputtering target which is made of a magnesium oxide sintered body having a purity of not less than 99.99% or not less than 99.995% by mass %, a relative density of not less than 98%, and an average grain size of not more than 8 ?m. The average grain size of the sputtering target is preferably not more than 5 ?m, more preferably not more than 2 ?m. A sputtered film having an excellent insulation resistance and an excellent homogeneity can be obtained by using the sputtering target.

Abstract: A sputtering target which is made of an alumina sintered body having a purity of not less than 99.99% by mass %, a relative density of not less than 98%, and an average grain size of less than 5 ?m or is made of an alumina sintered body having a purity of not less than 99.999% by mass % and a relative density of not less than 98%. A sputtered film having an excellent insulation resistance and an excellent homogeneity can be obtained by using the sputtering target.

Abstract: A sputtering target which is made of a magnesium oxide sintered body having a purity of not less than 99.99% or not less than 99.995% by mass %, a relative density of not less than 98%, and an average grain size of not more than 8 ?m. The average grain size of the sputtering target is preferably not more than 5 ?m, more preferably not more than 2 ?m. A sputtered film having an excellent insulation resistance and an excellent homogeneity can be obtained by using the sputtering target.

Abstract: Disclosed is a surface-treated ceramic member which has a coating film-formed surface comprising a ceramic sintered body with a porosity of 1% or less and a sol-gel coating film of a silicon alkoxide compound polymer formed on at least a part of a ceramic sintered body, wherein the coating film and the surface of the body are coexistent in the coating film-formed surface. Specifically the area of the sol-gel coating film accounts for 5 to 80% of the total area of the coating film-formed surface. The surface-treated ceramic member has excellent corrosion resistance and is free from scattering of particles.

Abstract: To provide a high purity Yttria sintered bodies having a high strength, a low dielectric loss and high plasma corrosion resistance of halogen gas during wide range surface roughness (Ra). An Yttria sintered body having a dielectric loss tan ? of 1×10?4 or less in the frequency range from 1 to 20 GHz, wherein the Yttria sintered body contains Yttria of 99.9% by mass or more, has a porosity of 1% or less and an average crystal grain size of 3 ?m or less, and the cumulative frequency ratio calculated from the following formula (1) is 3 or less: Cumulative frequency ratio=D90/D50. In the above-described formula (1), the meanings of the individual symbols are as follows: D90: The crystal grain size (?m) at which the cumulative number of grains as calculated from the smaller grain size side is 90% in the grain size distribution of the crystal grains in terms of the number of grains.

Abstract: Disclosed is a surface-treated ceramic member which has a coating film-formed surface comprising a ceramic sintered body with a porosity of 1% or less and a sol-gel coating film of a silicon alkoxide compound polymer formed on at least a part of a ceramic sintered body, wherein the coating film and the surface of the body are coexistent in the coating film-formed surface. Specifically the area of the sol-gel coating film accounts for 5 to 80% of the total area of the coating film-formed surface. The surface-treated ceramic member has excellent corrosion resistance and is free from scattering of particles.

Abstract: To provide a high-purity Yttria sintered bodies having a high strength, a low dielectric loss and high plasma corrosion resistance of halogen gas during wide range surface roughness (Ra). Solution An Yttria sintered body having a dielectric loss tan ? of 1×10?4 or less in the frequency range from 1 to 20 GHz, wherein the Yttria sintered body contains Yttria of 99.9% by mass or more, has a porosity of 1% or less and an average crystal grain size of 3 ?m or less, and the cumulative frequency ratio calculated from the following formula (1) is 3 or less: Cumulative frequency ratio=D90/D50 ??(1) In the above-described formula (1), the meanings of the individual symbols are as follows: D90: The crystal grain size (?m) at which the cumulative number of grains as calculated from the smaller grain size side is 90% in the grain size distribution of the crystal grains in terms of the number of grains.

Abstract: A high-strength machinable ceramic capable of high-precision fine machining has a coefficient of thermal expansion close to that of silicon and preferably a uniform blackish color which facilitates image processing of machined parts. The ceramic comprises a main constituent and a sintering aid. The main constituent comprises 30–59.95 mass % of boron nitride, 40–69.95 mass % of zirconia, optionally up to 20 mass % of silicon nitride and 0.05–2.5 mass % (calculated as an element) of at least one coloring additive, which is selected from C, Si, elements of Groups IIIA–IVB in the fourth period, elements of Groups IVA–VB in the fifth period, elements of Groups IVA–VIB in the sixth period of the long form periodic table, and compounds of these elements.

Abstract: A low-thermal-expansion, rigid and wear-resistant ceramic is provided. The low-thermal-expansion ceramic of the invention includes 60 vol % to 99.9 vol % of at least one selected from the group consisting of cordierite, spodumene and eucryptite and 0.1 vol % to 40 vol % of at least one selected from the group consisting of carbides, nitrides, borides and silicides of group IVa elements, group Va elements and group VIa elements, and boron carbide. The ceramic has a porosity of 0.5% or less and a thermal expansion coefficient, at 10° C. to 40° C., of 1.5×10?6/° C. or less.

Abstract: A high-strength machinable ceramic capable of high-precision fine machining has a coefficient of thermal expansion close to that of silicon and preferably a uniform blackish color which facilitates image processing of machined parts. The ceramic comprises a main constituent and a sintering aid. The main constituent comprises 30-59.95 mass % of boron nitride, 40-69.95 mass % of zirconia, optionally up to 20 mass % of silicon nitride and 0.05-2.5 mass % (calculated as an element) of at least one coloring additive, which is selected from C, Si, elements of Groups IIIA-IVB in the fourth period, elements of Groups IVA-VB in the fifth period, elements of Groups IVA-VIB in the sixth period of the long form periodic table, and compounds of these elements.

Abstract: A low-thermal-expansion, rigid and wear-resistant ceramic is provided.

Abstract: A process for producing silicon carbide-base complex is disclosed. In the process of this invention, a silicon carbide-base complex is produced by means of depositing carbon produced by means of pyrolysis of a gas comprising a hydrocarbon or a hydrocarbon halide on a porous synthesized silica glass body. As a result, the process of manufacture according to the present invention is capable of producing a high purity and a high strength silicon carbide-base material, which is useful as a jig for producing semiconductors, for example, a heat resistance jig material such as a process tube for wafer boats used for heat doping operation.