Generation of dislocations in annealed silicon wafers under applied stress

Generation of dislocations during heat treatment under applied stress was studied in silicon samples that underwent different multi-step anneals. Various types of oxygen precipitates (microdefects) were produced by multi-step anneals – as evidenced by TEM. These microdefects act as internal sources of dislocations when samples are further heat-treated under applied stress. The mechanical strength is remarkably sensitive to the microdefect type. The most efficient internal dislocation sources are large stacking faults and dislocation dipoles. The highest mechanical strength was found in samples containing only small platelet precipitates. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)