A method of forming a high purity ingot for wafer production, such as a silicon carbidewafer. Precursors are added to a reactor; at least part of a fiber is formed in the reactor from the precursors using chemical deposition interacting with the precursors; and granular material is then formed from the fiber. The method further includes forming the ingot from the granular material. In one aspect, the chemical deposition can include laser induced chemical vapor deposition. Further, the method can include separating one or more wafers from the ingot for use in semiconductor fabrication.

The present invention relates to a method for preparing a fully ceramic capsulated nuclear fuel material containing three-layer-structured isotropic nuclear fuel particles coated with a ceramic having a composition which has a higher shrinkage than a matrix in order to prevent cracking of ceramic nuclear fuel, wherein the three-layer-structured nuclear fuel particles before coating is included in the range of between 5 and 40 fractions by volume based on after sintering. More specifically, the present invention provides a composition for preparing a fully ceramic capsulated nuclear fuel containing three-layer-structured isotropic particles coated with the substance which includes, as a main ingredient, a silicon carbine derived from a precursor of the silicon carbide wherein a condition of ΔL.sub.c>ΔL.sub.m at normal pressure sintering is created, where the sintering shrinkage of the coating layer of the three-layer-structured isotropic nuclear fuel particles is ΔL.sub.c and the sintering shrinkage of the silicon carbide matrix is ΔL.sub.m; material produced therefrom; and a method for manufacturing the material. The residual porosity of the fully ceramic capsulated nuclear fuel material is 4% or less.

A composite sintered body, wherein the composite sintered body consists of ceramic composite sintered body, the ceramic composite sintered body comprises aluminum oxide as a main phase, and silicon carbide as a sub-phase, in which the composite sintered body has mullite in crystal grains of the aluminum oxide.

A process for preparing a sintered silicon carbide body including sintering a sample including silicon carbide particles to form a shaped sintered silicon carbide body, the particles containing a silicon carbide core and a surface layer containing carbon and oxygen, the sample having at least 90 weight % being C or Si and having a carbon to silicon molar ratio molC/molSi higher than 1 and a carbon in excess to oxygen molar ratio Cex/molO which is higher than 0.5 and lower than 5.3.

This electrostatic chuck device (1) includes a base (11) having one main surface serving as a mounting surface (19) on which a plate-shaped sample is mounted, and an electrode for electrostatic attraction (13) provided on the side opposite to the mounting surface (19) in the base (11), in which the base (11) consists of a ceramic material as a forming material, and the ceramic material contains aluminum oxide and silicon carbide as main components thereof, and has a layered graphene present at a grain boundary of the aluminum oxide.

Provided is a composite sintered body for an electrostatic chuck, which is not easily broken even if it is exposed to high-power plasma. Further, provided are an electrostatic chuck device using such a composite sintered body for an electrostatic chuck and a method of manufacturing a composite sintered body for an electrostatic chuck. The composite sintered body for an electrostatic chuck is a composite sintered body including an insulating ceramic and silicon carbide, in which crystal grains of the silicon carbide are dispersed in at least one selected from the group consisting of a crystal grain boundary and a crystal grain of a main phase formed by sintering crystal grains of the insulating ceramic.

A composite sintered body including: a metal oxide as a main phase; silicon carbide as a sub-phase; and silicate of a metal element that is included in the metal oxide, in which the average aggregation diameter of the silicate in the field of view of 600 μm.sup.2 at a magnification of 1000 times is 5 μm or lower.

The present invention relates to a method for preparing a fully ceramic capsulated nuclear fuel material containing three-layer-structured isotropic nuclear fuel particles coated with a ceramic having a composition which has a higher shrinkage than a matrix in order to prevent cracking of ceramic nuclear fuel, wherein the three-layer-structured nuclear fuel particles before coating is included in the range of between 5 and 40 fractions by volume based on after sintering. More specifically, the present invention provides a composition for preparing a fully ceramic capsulated nuclear fuel containing three-layer-structured isotropic particles coated with the substance which includes, as a main ingredient, a silicon carbine derived from a precursor of the silicon carbide wherein a condition of ΔL.sub.c>ΔL.sub.m at normal pressure sintering is created, where the sintering shrinkage of the coating layer of the three-layer-structured isotropic nuclear fuel particles is ΔL.sub.c and the sintering shrinkage of the silicon carbide matrix is ΔL.sub.m; material produced therefrom; and a method for manufacturing the material. The residual porosity of the fully ceramic capsulated nuclear fuel material is 4% or less.

The present invention relates to a method for preparing a fully ceramic capsulated nuclear fuel material containing three-layer-structured isotropic nuclear fuel particles coated with a ceramic having a composition which has a higher shrinkage than a matrix in order to prevent cracking of ceramic nuclear fuel, wherein the three-layer-structured nuclear fuel particles before coating is included in the range of between 5 and 40 fractions by volume based on after sintering. More specifically, the present invention provides a composition for preparing a fully ceramic capsulated nuclear fuel containing three-layer-structured isotropic particles coated with the substance which includes, as a main ingredient, a silicon carbine derived from a precursor of the silicon carbide wherein a condition of ΔL.sub.c>ΔL.sub.m at normal pressure sintering is created, where the sintering shrinkage of the coating layer of the three-layer-structured isotropic nuclear fuel particles is ΔL.sub.c and the sintering shrinkage of the silicon carbide matrix is ΔL.sub.m; material produced therefrom; and a method for manufacturing the material. The residual porosity of the fully ceramic capsulated nuclear fuel material is 4% or less.

An electrostatic chuck device includes: a base having one principal surface which is a placing surface on which a plate-shaped sample is placed, wherein the base is made from a sintered compact of ceramic particles, which include silicon carbide particles and aluminum oxide particles, as a forming material; and an electrostatic attraction electrode which is provided on a surface of the base on the side opposite to the placing surface of the base, or in the interior of the base, in which the volume resistivity value of the sintered compact is 0.5×10.sup.15 Ωcm or more in the entire range from 24° C. to 300° C., a graph which shows the relationship of the volume resistivity value of the sintered compact to a temperature at which the volume resistivity value of the sintered compact is measured has a maximum value in the range from 24° C. to 300° C., and the amount of metal impurities in the sintered compact other than aluminum and silicon in the sintered compact is 100 ppm or less.