Thermal oxidation of silicides

Abstract

Kinetics of thermal oxide growth on silicides MoSi2, WSi2, TaSi2, and TiSi2 deposited over polycrystalline and single-crystal silicon were investigated. Both steam and dry O2 oxidations in the temperature range of 750–1200 °C were examined. An oxidation kinetic model for silicides which accounts for diffusion processes of silicon through the silicide layer and oxidant through the growing oxide, and the interface chemical reaction was developed. This model uses the Deal–Grove silicon oxidation approach. The significantly larger linear rate constants and greatly reduced activation energies of the linear rate constants of silicides in relation to single-crystal silicon oxidations are predicted by this model. The similarity of parabolic rate constants and their activation energies for silicon oxidations is also in excellent agreement with the model.