The enhancement effect of Fe impurities upon the generation of surface and bulk micro-defects, such as oxidation-induced stacking faults, oxide precipitates, precipitate-dislocation complexes and bulk stacking faults, was observed in annealed wafers which had been prepared from Czochralski-grown crystals that were intentionally contaminated with Fe. The effect remained significant even at an Fe concentration as low as 1012/cm3. It was found that Fe facilitated the nucleation of oxide precipitates. The Fe-assisted nucleation of oxide precipitates was considered, and the effect of Fe upon the generation of oxidation-induced stacking faults could be explained by assuming that both oxide precipitates and Fe-Si precipitates which formed near to the wafer surface acted as active nucleation sites for the micro-defects.

J.Jablonski, M.Saito, Y.Miyamura, M.Imai: Japanese Journal of Applied Physics, 1996, 35[1-2A], 520-5