# A novel intrinsic interface state controlled by atomic stacking sequence at interfaces of SiC/SiO$_2$

## TL;DR

This study uses ab-initio calculations to reveal that the atomic stacking sequence at SiC/SiO2 interfaces creates intrinsic localized electron states, affecting device performance.

## Contribution

It uncovers a new class of interface states controlled by stacking sequence, previously unrecognized, impacting electronic properties of SiC/SiO2 interfaces.

## Key findings

- Interface states are sensitive to stacking sequence.
- Electron doping alters the energetics of stacking structures.
- New interface states exist between 0.3 eV below and 1.2 eV above CBM.

## Abstract

On the basis of ab-initio total-energy electronic-structure calculations, we find that interface localized electron states at the SiC/SiO$_2$ interface emerge in the energy region between 0.3 eV below and 1.2 eV above the bulk conduction-band minimum (CBM) of SiC, being sensitive to the sequence of atomic bilayers in SiC near the interface. These new interface states unrecognized in the past are due to the peculiar characteristics of the CBM states which are distributed along the crystallographic channels. We also find that the electron doping modifies the energetics among the different stacking structures. Implication for performance of electron devices fabricated on different SiC surfaces are discussed.