High-temperature oxidation behavior of chemical vapor deposited silicon carbide

Abstract

The transitions from active to passive oxidation and from passive oxidation to bubble formation for CVD SiC were determined by changing oxygen partial pressures in O2-Ar, CO2-Ar and CO-CO2 atmospheres at temperatures from 1600 to 2000 K. The active-to-passive transition behavior was significantly different between O2-Ar and CO-CO2 atmosphere, however the transition kinetics in both atmospheres were well explained by Wagner model, volatility diagram and numerical thermodynamic calculation. The transition behavior from passive oxidation to bubble formation was understood by calculating the equilibrium vapor pressures of SiO and CO at the SiO2/SiC interface.