| 摘要 |
PURPOSE:To simply obtain a semiconductor wafer, which has little surface defect, has no resistance variation, has a clean surface and has a gettering ability, by a method wherein the semiconductor wafer is applied with a thermal treatment in a reducing atmosphere of high temperatures of 1,100 deg.C or more and the semiconductor wafer is subjected to a heat treatment at temperatures of 600-800 deg.C. CONSTITUTION:A semiconductor wafer is performed a thermal treatment in a reducing atmosphere of high temperature of 1,100 deg.C or more, the solid oxygen in the vicinity of the surface of the wafer is made an outward diffusion and, at the same time, the defect to generate at the time of crystal growth is uniformly solid-solubilized. After that, a heat treatment is performed at temperatures of 600-800 deg.C. If the temperatures at the time of the first-stage heat treatment are set at below 1,100 deg.C, it not only becomes impossible to make an outward diffusion sufficiently the solid oxygen in the vicinity of the surface of the semiconductor wafer but also becomes difficult to solid-solubilize uniformly the defect to generate at the time of crystal growth. By making the atmosphere at the time of the first-stage thermal treatment into a reducing one, the oxygen in vicinity of the surface of the semiconductor wafer is effectively made an outward diffusion and, at the same time, the depth of the wafer surface layer to be made an outward diffusion can be made deeper. If the temperature range at the time of the second-stage heat treatment is deviated from the above-mentioned temperature range, it becomes impossible to produce a sufficient defect in the interior of the semiconductor wafer. |
