Structure and energetics of carbon-related defects in SiC (0001)/SiO${}_2$ systems revealed by first-principles calculations: Defects in SiC, SiO${}_2$, and just at their interface

Abstract

We report first-principles calculations that reveal the atomic forms, stability, and energy levels of carbon-related defects in SiC (0001)/SiO${}_2$ systems. We clarify the stable position (SiC side, SiO${}_2$ side, or just at the SiC/SiO${}_2$ interface) of defects depending on the oxidation environment. Under an O-rich condition, the di-carbon antisite ((C${}_2$)${}_{\mathrm{Si}}$) in the SiC side is stable and critical for $n$-channel MOSFETs, whereas the di-carbon defect (Si-C-C-Si) at the interface becomes critical under an O-poor condition. Our results suggest that the oxidation of SiC under a high-temperature O-poor condition is favorable in reducing the defects, in consistent with recent experimental reports.

arXiv comment17 pages, 10 figures

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