Scanning tunneling microscopy and spectroscopy of cubic β-SiC(111) surfaces

Scanning tunneling microscopy (STM) images show a 6 × 6 reconstruction of the β-SiC(111) surface annealed at 1150–1200°C. Contrast reversal is observed as tunneling voltage bias is reversed. Spectroscopic I/ V data indicate the presence of a graphite layer on the top surface. A model of the surface is proposed where an incommensurate graphite monolayer is grown over a (1 × 1) Si-terminated β-SiC(111) surface. This model helps to explain the discrepancy between the 6√3 × 6√3 geometry observed by LEED and the 6 × 6 geometry observed by STM on the same surface.