Stable surface termination on vicinal 6H–SiC(0 0 0 1) surfaces

Ordered nanofacet structures on vicinal 6H–SiC(0 0 0 1) surfaces, consisting of pairs of a (0 0 0 1) basal plane and a ( 1 1 2 ¯ n ) facet, are investigated in terms of stable surface stacking of the (0 0 0 1) basal planes. The surface termination of S3 (or S3*), i.e., ABC (or A*C*B*), was suggested by a structural model based on quantized step-bunching, which typically gives a one-unit-cell bunched step configuration at the ( 1 1 2 ¯ n ) facet. Here, we evaluate the surface termination at basal planes covered with a layer of silicon oxynitride by means of quantitative low-energy electron diffraction (LEED) analysis combined with scanning tunneling microscopy (STM), and show the validity of the structural model proposed.