Polytype determination at the SiC-SiO2 interface by internal electron photoemission scattering spectroscopy

The characteristic energy loss corresponding to band-to-band electron excitation at the SiC surface is observed in the internal photoemission (IPE) spectra of SiC-SiO2 interfaces for three polytypes of SiC (4H, 6H, and 15R). From this feature the SiC bandgap width at the interface with thermal oxide was found to be the same as in the bulk of SiC. This importantly indicates that oxidation in dry O2 at temperatures as high as 1300 deg. C does not lead to polytypic transition in SiC