Anomalous oxidation rate in 6H-SiC depending on the partial pressure of O2 and H2O

Abstract

On the thermal oxidation of silicon carbide, the partial pressure of H2O affects the oxidation rate very differently from silicon. We have found that the oxide thickness shows the bell-shape as the function of the relative partial pressure of H2O, called the p parameter. The main reason for this is that the diffusion limiting process diminishes according to the reduction of p while the linear rate constant does not depend on p strongly until p=0.15. The reduction of the oxide thickness below p=0.15 is explained by the abrupt reduction of the linear rate constant. In addition, the interface quality for oxides grown in the different p has been investigated. For the reduction of the surface states, the large p (over p=0.8) is favorable.