A systematic study of the level positions of intrinsic and C defects in SiO2 was presented, based on density functional calculations with a hybrid functional in an α-quartz super-cell. The results were analyzed from the point of view of the near-interface traps, observed in both SiC/SiO2 and Si/SiO2 systems, and assumed to have their origins in the oxide. It was shown that the vacancies and the O interstitial could be excluded as the origin of such near-interface traps, while the Si interstitial and C dimers give rise to gap levels in the energy range inferred from experiments. The properties of these defects were considered in light of understanding of the SiC/SiO2 interface.

Defects in SiO2 as the Possible Origin of Near Interface Traps in the SiC/SiO2 System - a Systematic Theoretical Study. J.M.Knaup, P.Deák, T.Frauenheim, A.Gali, Z.Hajnal, W.J.Choyke: Physical Review B, 2005, 72[11], 115323 (9pp)