Bonding at the SiC-SiO2 interface and the effects of nitrogen and hydrogen

Unlike the Si-SiO2 interface, the SiC-SiO2 interface has large defect densities. Though nitridation has been shown to reduce the defect density, the effect of H remains an open issue. Here we combine experimental data and the results of first-principles calculations to demonstrate that a Si-C-O bonded interlayer with correlated threefold-coordinated C atoms accounts for the observed defect states, for passivation by N and atomic H, and for the nature of residual defects.