Abstract: Provided is a more appropriate method of producing lithium sulfide having high ionic conductivity and no by-products generated. The method of producing lithium sulfide includes a temperature rising step (Step S14) of reducing lithium sulfate fed into a furnace in a state of heating to a temperature of more than 700° C. under an atmosphere of a reduced pressure of 0.05 MPa or less.

Abstract: A method for producing lithium sulfide includes: a preparation process (step S12) at which a raw material and a reducing agent are charged into a furnace, the raw material being mainly composed of lithium sulfate having a property of weight loss of 5% or more to 25% or less upon heating to 120° C.; and a temperature raising process (step S14) at which the raw material and the reducing agent are heated in the furnace to raise the temperature.

Abstract: A high purity copper sputtering target material includes Cu at a purity of 99.99998 mass % or more excluding O, H, N and C, wherein an Al content is 0.005 mass ppm or less, a Si content is 0.05 mass ppm or less, an Fe content is 0.02 mass ppm or less, a S content is 0.03 mass ppm or less, Cl content is 0.1 mass ppm or less, n O content is 1 mass ppm or less, H content is 1 mass ppm or less, a N content is 1 mass ppm or less, and a C content is 1 mass ppm or less.

Abstract: A high purity copper sputtering target material includes Cu at a purity of 99.99998 mass % or more excluding O, H, N and C, wherein an Al content is 0.005 mass ppm or less, a Si content is 0.05 mass ppm or less, an Fe content is 0.02 mass ppm or less, a S content is 0.03 mass ppm or less, Cl content is 0.1 mass ppm or less, n O content is 1 mass ppm or less, H content is 1 mass ppm or less, a N content is 1 mass ppm or less, and a C content is 1 mass ppm or less.

Abstract: The present invention relates to a silicon part and a method of producing the silicon part. The silicon part is not worn quickly and particle formation is suppressed even if it is positioned in the reaction chamber of a plasma etching apparatus. The silicon part for the plasma etching apparatus is made of any one selected from a group consisting of poly-crystalline silicon, mono-like silicon, and single-crystalline silicon. Also, the silicon part includes boron as a dopant in a range from 1×1018 atoms/cc or higher to 1×1020 atoms/cc or lower.

Abstract: The present invention relates to a silicon part and a method of producing the silicon part. The silicon part is not worn quickly and particle formation is suppressed even if it is positioned in the reaction chamber of a plasma etching apparatus. The silicon part for the plasma etching apparatus is made of any one selected from a group consisting of poly-crystalline silicon, mono-like silicon, and single-crystalline silicon. Also, the silicon part includes boron as a dopant in a range from 1×1018 atoms/cc or higher to 1×1020 atoms/cc or lower.