Intrinsic origin of electron scattering at 4H-SiC(0001)/SiO$_2$

TL;DR

This study uses first-principles calculations to reveal that oxygen-related internal-space states cause significant electron scattering at the 4H-SiC/SiO₂ interface, surpassing defect-related effects.

Contribution

It uncovers the intrinsic scattering mechanism at the SiC/SiO₂ interface driven by internal-space states, not electrically active defects.

Findings

Oxygen introduces large scattering effects.

Internal-space states dominate scattering behavior.

Scattering exceeds that caused by carbon-related defects.

Abstract

We introduce a first-principles study to clarify the carrier-scattering property at the SiC/SiO$_2$. Interestingly, the electron transport at the conduction-band edge is significantly affected by the introduction of oxygen, even though there are no electrically active defects. The origin of the large scattering is explained by the behavior of the internal-space states (ISSs). Moreover, the effect of the ISSs is larger than that of the electrically active carbon-related defects. This result indicates that an additional scattering not considered in a conventional Si/SiO$_2$ occurs at the SiC/SiO$_2$.