Impact of interface structure on electronic states in 4H-SiC inversion layer

Abstract We investigate impact of interface structures on the electronic states in the 4H-SiC(0001) inversion layers, considering the full band structure of bulk 4H-SiC by using the empirical pseudopotential method (EPM). Our results reveal that a certain interface structure has a dead layer which repels electrons from the interface by about 0.3 nm. In addition, it is found that the contribution of an upper conduction band valley of bulk 4H-SiC leads to a strong localization of the electronic state of the 1st subband under high confinement electric fields. We also perform calculations based on the effective mass approximation (EMA) and compare the subband energies between results of the EPM and the EMA. This comparison reveals that the impact of the full band structure considered in the EPM calculation is comparable to doubling the effective mass in the EMA calculation.