Surface analysis of 6HSiC

The composition of {0001} surfaces of 6HSiC samples was studied by using low-energy electron diffraction, Auger electron (AES), and X-ray photoelectron spectroscopy (XPS/SXPS). The samples were cleaned in ultrahigh vacuum by heating them either in the presence of a Si flux at different temperatures or by annealing at 1170 K for 10 min. Depending on the preparation method and temperature used four reconstructions were observed: (1 × 1), (3 × 3), (√3 × √3)R30°, and (6√3 × 6√3)R30°. The compositions of the reconstructions and the chemical bonding of the surface atoms were characterized using AES and XPS/SXPS. Models for the reconstructions are proposed.