Chemical States of Crystalline Silicon Carbide Surfaces

Chemical states of 6H polytype crystalline silicon carbide (6H-SiC) surfaces were investigated using X-ray photoelectron spectroscopy (XPS). Surface contaminants such as C-C, C-H and C-O species were evaluated from C1s photoelectron spectra after treatment under various conditions. Clean SiC surfaces were found to appear after the chemical etching of a thermal oxide ( SiO 2 ) film using a buffered HF solution. Furthermore, to clarify the chemical etching characteristics of SiO 2 formed on 6H-SiC substrates, the depth profiling of the SiO 2 was also performed using XPS. The C1s peak at a binding energy of about 286.2 eV was detected on the surfaces of the 6H-SiC substrates at the moment when only the SiO 2 was completely removed, and the C1s peak was characterized as due to the C-O bonds formed near the SiO 2 /SiC interface.