High-temperature active oxidation of CVD-Si 3N 4 in ArO 2 atmosphere

Abstract

Active oxidation of CVD-Si 3N 4 in ArO 2 atmospheres was investigated at temperatures from 1823 to 1923 K. Active oxidation rates increased with increasing oxygen partial pressure, temperature and total gas flow rate. The rate-controlling step for active oxidation is oxygen diffusion through a gaseous boundary layer. The transition from active to passive oxidation was observed at a certain oxygen partial pressure. The transition behavior is discussed using Wagner's model.