Nucleation of CuSi precipitate colonies in oxygen-rich silicon

The nucleation of CuSi precipitate colonies in silicon containing substantial amounts of oxygen has been studied by transmission electron microscopy. It is shown that oxygen in Si can influence precipitation of Cu by generating prismatic dislocation loops at the interface between the Si matrix and oxygen-rich precipitates. Such loops act as nucleation sites for CuSi precipitates, which form star-shaped colonies upon continued solid solution decomposition.