退火直拉硅单晶中氧沉淀和诱生缺陷的电子显微镜研究

本文用超高压透射电子显微镜研究退火的高氧含量无位错直拉硅单晶中氧沉淀和诱生缺陷。在750—1050℃范围内氧沉淀是球状的α方英石。除了球状氧沉淀粒子之外还有一些具有{001}惯习面的方片状氧沉淀物。在950℃以上沿〈110〉方向从氧沉淀发射出冲压式棱柱位错环。这些位错环的柏氏矢量为α/2〈110〉、环面法线为〈110〉,它们是间隙型的位错环。这些位错环是从方片状氧沉淀物或从球伏氧沉淀粒子的聚集团发射出来的。当它们遇到障碍物时可能产生比较复杂的位错组态。实验中观察到由于层错攀移形成的台阶。热处理温度在850℃以下时,未观察到体内层错。关键词：

TEM INVESTIGATION OF OXYGEN PRECIPITATES AND INDUCED DEFECTS IN ANNEALED CZ-Si SINGLE CRYSTAL

In this paper, oxygen precipitates and induced defects in annealed dislocation-free CZ-Si with high oxygen content have been investigated by HVEM. The oxygen precipitates are spherical crystobalite at 750-1050℃. In addition to spherical precipitates, there are some square plate-like oxygen precipitates with {001} habit plane. Punching prismatic dislocation loops are emitted from oxygen precipitates along 〈110〉 directions above 950℃.The loops are interstitial loops with Burgers vector α/2〈110〉 and axis 〈110〉.The loops are generated by a square plate-like precipitate or by a cluster of spherical precipitates. When dislocation loop encounters obstacle, the complex dislocation configuration may be produced. A stage in a stacking fault has been observed, it is formed by climb of the stacking fault. If treatment temperature is below 850℃, no bulk stacking fault results.