Effect of oxidation and reoxidation on the oxide-substrate interface of 4H- and 6H-SiC

X-ray photoelectron spectroscopy and sputter depth profiling were used to investigate SiO2 grown on 4H- and 6H-SiC with and without a reoxidation procedure. The oxides grown and oxide-substrate interfaces formed on 4H and 6H were similar in chemistry but different from Si(100). Reoxidation changes the structure of the oxide and the abruptness of the oxide-substrate interface. We propose a model for SiC oxidation where a transition layer containing Si–Si bonds is produced between the oxide and the SiC substrate.