Computational analysis of 4H-SiC/SiO 2 interfaces: atomic structure, electronic properties, and interfacial reaction kinetics

The 4H-SiC/SiO 2 interface plays a central role in determining the electrical performance of SiC-based metal oxide semiconductor devices, including field-effect transistors. However, a unified understanding that consistently connects atomic-scale processes with macroscopic device characteristics remains elusive, owing to oxidation-induced disorder and pronounced orientation-dependent reactions. This review summarizes computational studies of the atomic and electronic structures of 4H-SiC/SiO 2 interfaces, together with the effects of post-oxidation annealing. Density functional calculations reveal that thermal oxidation proceeds primarily via CO desorption, with energy barriers and reaction pathways strongly dependent on surface orientation and local bonding configurations. The oxidation generates interfacial defects, such as carbon-related complexes and dangling bonds, which introduce localized states. The incorporation of nitrogen by post-oxidation annealing leads to structural reconstruction, passivates defects, and modifies interface dipoles, thereby reducing interface state density and altering band offsets. These insights provide a microscopic foundation for interface engineering toward improved device performance.