| 摘要 |
PURPOSE:To form an SiO2 polycrystalline target porcelain to be used for a sputtering of a complicated shape requiring dimensional accuracy by a method wherein the SiO2 purity of raw material, the density and the crystal grain diameter of a sintered body are specified properly. CONSTITUTION:The SiO2 powder obtained by performing the commercially available sedimentation method is calcined in the air at 900 deg.C, the calcined material is pulverized using a ball mill wherein agate is used as a ball, and the grain diameter after pulverization of 0.8+ or -0.2 mum is obtained for the average grain diameter of raw material of 0.4+ or -2 mum. After this souffle is dried up, it is granulated by adding a caking material of methyl cellulose, and dry-formed into cylindrical shape. The molding pressure is t-o be 300 kg/cm<2> or above, and a higher strength can be obtained as the molding pressure becomes higher. This molded body is molded by applying hydrostatic pressure, and it is fully dried up, a cutting work is performed on the molded body 1. The density of the molded body after performance of the hydrostatic pressure molding is 0.8-1.3g/cm<2>. At this point, the strength of the molded body is not strong at the density lower than 0.8g/cm<2>, and a cutting work is hardly performed at the density hi-gher than 1.3g/cm<2> because it is hard and fragible. The molded body 1 thus obtained is solidified by sintering in the atmospheric air of 850-1050 deg.C for approximately two hours, and the target porcelain of 0.9-1.5g/cm<2> in density is obtained. |
