Electronic structure of oxidized SiC(0 0 0 1) studied by inverse photoemission spectroscopy

Starting from the silicon rich (3 × 3) reconstruction of SiC(0 0 0 1) we prepared oxidized surfaces by hydrogen etching as well as by exposure to molecular oxygen. LEED pictures show a (1 × 1)-reconstructed surface with a faint (3×3)R30° structure being more pronounced for the hydrogen-etched surfaces. Auger spectra reveal a distinct change in the shape of the SiLVV peak indicating the existence of Si-O bonds on the surface. Inverse photoemission (IPE) is employed to study the electronic structure above the Fermi level of the oxidized samples. On the hydrogen-etched surface difference spectra reveal a surface feature at 1 eV above the Fermi level that presumably originates from an isolated dangling bond on ordered patches of the oxidized surface.