| 摘要 |
PROBLEM TO BE SOLVED: To produce a dense sintered compact of boron carbide, capable of being applied to a semiconductor dry etching and having high purity and a high strength by allowing boron carbide to include a silicon compound in a specific amount, regulating the content of alkali metal, alkaline earth metal and a transition metal so as to be less than a specific value and further regulating a density so as to be larger than a specified relative density. SOLUTION: This sintered compact of boron carbide contains specific amounts of a silicon compound, an alkali metal, an alkaline earth metal and a transition metal. The silicon compound is preferably silicon carbide, and content is preferably 0.05-5 wt.%. The contents of the alkali metal, the alkaline earth metal and the transition metal are each <=100 ppm, preferably 10 ppm. A boron carbide powder having <=5 μm average particle diameter is mixed with the silicon carbide having <=1 μm average particle diameter, compacted by a press or the like and subjected to purification treatment in vacuum of <=5 Pa at 1,600-2,100 deg.C so as to have <=100 ppm content of the alkali metal, etc. The purified compact is fired in argon gas at <=2250 deg.C to form the compact into the dense one in the method for producing the sintered compact of the baron carbide. The sintered compact of the boron carbide is an electroconductive material with a high strength and excellent in plasma resistance against a halogen plasma or the like. |
