Intrinsic Origin of Negative Fixed Charge in Wet Oxidation for Silicon Carbide

Yasuhiro Ebihara; Kenta Chokawa; Shigenori Kato; Katsumasa Kamiya; Kenji Shiraishi

doi:10.1063/1.4722782

paper

Intrinsic Origin of Negative Fixed Charge in Wet Oxidation for Silicon Carbide

arXiv:1204.5556 · doi:10.1063/1.4722782

Abstract

We demonstrate on the basis of first-principles calculations that the formation of carbonate-like moiety in SiO $_{2}$ could be the intrinsic origin of negative fixed charge in SiC thermal oxidation. We find that two possible origins for the negative fixed charges are O-lone-pair state and a negatively charged CO $_{3}$ ion in SiO $_{2}$ . Such CO $_{3}$ ion is able to be formed as a result of the existence of residual C atoms in SiO $_{2}$ , which are expected to be emitted from the interface between SiC and SiO $_{2}$ , and the incorporation of H atoms during wet oxidation.