Transmission electron microscopy was used to study monocrystals which contained stacking faults, and the effect of Cu diffusion was investigated. When no Cu was introduced, hexagonal stacking faults with hexagonal Si oxide precipitates were observed. When Cu diffusion had occurred, stacking faults which had branches with CuSi precipitates on the edges or inner parts of these branches were seen. The CuSi precipitates grew on the Frank dislocation loop, and interstitial Si atoms were released. The interstitial Si atoms condensed around the CuSi precipitates, and branches oriented in [110]-type directions grew from the stacking faults.

S.Aoki: Journal of the Japan Institute of Metals, 1991, 55[10], 1039-44