1210.7899 (Xiao Shen et al.)

Competing Atomic and Molecular Mechanisms of Thermal Oxidation    [PDF]

Xiao Shen, Sokrates T. Pantelides

The oxidation of SiC and Si provide a unique opportunity for studying oxidation mechanisms because the product is the same, SiO2. Silicon oxidation follows a linear-parabolic law, with molecular oxygen identified as the oxidant. SiC oxidation obeys the same linear-parabolic law but has different rates and activation energies and exhibits much stronger face-dependence. Using results from first-principles calculations, we show that atomic and molecular oxygen are the oxidant for Si- and C-face SiC respectively. Comparing SiC with Si, we elucidate how the interface controls the competition between atomic and molecular mechanisms.

View original: http://arxiv.org/abs/1210.7899