First Principles Studies on the Interfaces of Wide Gap Semiconductors

Abstract

We have investigated the interfaces of wide gap semiconductors by using first principles calculations. We show that oxidation of SiC induces the formation of C-C bond defects at SiC/SiO₂ interfaces which corresponds to the oxidation front of SiC. We also find that this C-C bond formation leads to the formation of shallow interface states near the SiC conduction band bottoms. Moreover, we clarify the mechanism of hole generation on H-terminated diamond surfaces by the adsorption of molecules whose lowest unoccupied molecular orbital (LUMO) levels or single occupied molecular orbitals (SOMO) levels are located lower than the valence band top of H-terminated diamonds.