Atomic‐Level Characterization of Cubic Silicon Carbide Surfaces—A Review

Abstract

Scanning tunneling microscopy (STM) images of the cubic β‐SiC (100) and β‐SiC (111) surfaces are taken after annealing to 1200°C to eliminate the surface oxide. Low‐energy electron diffraction (LEED) patterns of the β‐SiC (111) surface show a 6 √ 3 × 6 √ 3 geometry, while STM images show a 6 × 6 geometry. Contrast reversal is observed as tunneling voltage bias is reversed. Spectroscopic I/V measurements 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 LEED pattern and the 6 × 6 geometry observed in STM images. Charge transfer between certain carbon atoms and silicon atoms gives rise to the 6 × 6 geometry and the contrast reversal.