Defect generation on mechanical surface defects before and after the oxidation (I). TEM investigations on the nucleation of oxidation stacking faults at mechanically induced weak surface defects

In order to obtain information on the nucleation mechanism of oxidation stacking faults, mechanically induced weak surface defects as simulated by low-load scratches were investigated with TEM before and after a short-time wet oxidation at 1050 °C. The experimental results could not confirm the existing models which explain stacking fault nucleation by the splitting of complete dislocations. Rather it was found that clusters of silicon interstitials are generated due to strong local compression during scratching, which then act as nuclei for stacking faults in the subsequent oxydation process.