Origins of Negative Fixed Charge in Wet Oxidation for SiC

We demonstrate that the formation of carbonate-like moiety in SiO2 could be the origin of negative fixed charge in SiC thermal wet oxidation, based on first-principles calculations. We find that negative CO3 ion appears in SiO2 due to not only the existence of residual C atoms that are expected to be emitted from the SiC/SiO2 interface, but also a large enough number of incorporated H atoms during wet oxidation.