Density functional theory study on the effect of NO annealing for SiC(0001) surface with atomic-scale steps

The effect of NO annealing on the electronic structures of the 4H-SiC(0001)/SiO2 interface with atomic-scale steps is investigated. The characteristic behavior of conduction band edge (CBE) states is strongly affected by the atomic configurations in the SiO2 and the step structure, resulting in the discontinuity of the CBE states at the step edges, which prevents electrons from penetrating from the source to drain and decreases the mobile free-electron density. We found that the behavior of the CBE states becomes independent from the atomic configuration of the SiO2 and the density of the discontinuities is reduced after NO annealing.