Shrinkage and growth of oxidation stacking faults during thermal nitridation of silicon and oxidized silicon

Abstract

We have studied the shrinkage and growth of preexisting oxidation-induced stacking faults during thermal nitridation of silicon without oxide film and of oxidized silicon with oxide film 23 to 5600 Å thick. Nitridation was carried out at 1050 to 1200 °C under ammonia partial pressures of 10−3 to 4 kg/cm2. We observed that stacking faults in silicon without oxide film shrink linearly with nitridation time and their shrinkage rate increased as the partial pressure of ammonia increased. On the other hand, stacking faults in oxidized silicon with oxide film grew during nitridation and their growth rate increased with the increase of ammonia partial pressure after the pressure reached about 10−1 kg/cm2 and with the increase of the thickness of the oxide film. Based on these results, we have proposed a model which assumes that in the shrinkage phenomenon, an undersaturation of silicon self-interstitials occurs near the silicon surface because of silicon-cation migration from the silicon-nitride interface to the nitride surface. The model also assumes that the growth phenomenon occurs because of the supersaturation of silicon self-interstitials, which are generated by the reaction of ammonia with silicon dioxide and are injected into the bulk of silicon through the silicon-nitride interface. The projected results of this model agree reasonably well with the experimental results.