Composition analysis of SiO2/SiC interfaces by electron spectroscopic measurements using slope-shaped oxide films

We have characterized SiO2/SiC interfaces by X-ray photoelectron spectroscopy in terms of composition and bonds to clarify the reasons for the problems in silicon carbide metal-oxide-semiconductor field-effect-transistor and MOS structures. The oxide films on 6H–SiC were shaped into slopes by HF chemical etching to obtain the depth profile of the composition and the bondings. An interface layer was found near the SiO2/SiC boundary, where SiO2 stoichiometry is collapsed and there exists the bondings other than Si–O2 and Si–C. Also, we revealed the differences in the interface properties for different oxidation processes.