Changes in the morphologies of thermally induced oxide precipitates were studied by means of the transmission electron microscopic examination of Czochralski wafers which were deformed in tension at 850 or 950C. Precipitates with complex shapes were frequently observed in specimens which had been deformed at 950C. Some octahedral oxide precipitates were observed to expand at the vertices of square shapes in plan-view specimens which were heat-treated (1050C, 8h) after deformation at 950C. The precipitates grew on residual dislocations around octahedral oxide precipitates. These observations suggested that a large number of vacancies formed, in the vicinity of octahedral oxide precipitates, due to interaction with by-passing dislocations.

Morphology Change of Octahedral Oxide Precipitates in Czochralski Silicon Wafers Stretched in Tension. K.Ojima, K.Sakai, T.Yamagami: Japanese Journal of Applied Physics - 1, 2000, 39[10], 5723-6