Influence of fluorine on oxidation-induced stacking faults

To investigate the influence of fluorine on OISF (oxidation-induced stacking faults), samples in which fluorine or BF2 ions were implanted into SiO2 film on the Si substrates were prepared. These samples were oxidized in dry O2 or wet O2 at 1100–1200 °C and subsequently the length of OISF was examined using Secco etchant. Shrinkage of OISF was observed in dry O2 oxidation. On the other hand, in wet O2 no shrinkage of OISF was observed. These results can be explained by differences in the fluorine concentration profile in the oxide. It was further concluded that fluorine in the oxide near the SiO2-Si interface plays an important role in the shrinkage of OISF.