First-principles modeling of defect-free abrupt SiC/SiO2 interfaces on a- and m-face 4H-SiC

While the a- and m-faces of 4H-SiC have attracted increasing interest for SiC metal–oxide–semiconductor device applications, the electronic and/or geometric structures of their SiC/SiO2 interfaces are still unknown. We constructed model structures of "defect-free" abrupt SiC/SiO2 interfaces. Even with C–O bonds at the interface and/or an uneven interfacial boundary, their electronic properties show only slight difference from those of the Si-face with a flat interface and no-interface C–O bonds. Our results offer a starting point for studying whether the smaller number of defects for a- and m-faces compared with the Si-face is related to the intrinsic properties of the interface or to oxidation processes.