Angle-resolved photoelectron spectroscopy study of initial stage of thermal oxidation on 4H-SiC(0001)

A key to improving the performance of SiC MOSFETs is to clarify the SiO2/SiC interface structure formed by thermal oxidation. We have investigated the initial stage of thermal oxidation on 4H-SiC(0001) by angle-resolved photoelectron spectroscopy. From the changes in the Si 2p(3/2) and C 1s photoelectron spectra, the changes in the chemical bonding state of the SiO2/SiC structure with the progress of thermal oxidation were observed. We also found that the intensity of C-O bonds in the case of 4H-SiC(0001) was smaller than that in the case of 4H-SiC(0001) with the same oxide thickness and that the oxidation rate of 4H-SiC(0001) is already slower than that of 4H-SiC(0001) in the early stage of oxidation. (C) 2016 The Japan Society of Applied Physics