Surface photovoltage and Auger electron spectromicroscopy studies of HfO2/SiO2/4H-SiC and HfO2/Al2O3/4H-SiC structures

► We applied contactless surface photovoltage to assess oxide/SiC interface quality. ► 5 nm-thick SiO2 film seems to be better interlayer between SiC and HfO2 than Al2O3. ► Element distribution in the oxide/SiC interface was obtained from AES profiling. ► SiO2 buffer and transition silicate nanofilms were found from AES spectra analysis.