The formation of a new class of step-and-terrace structure on the 4H-SiC(00•1) surface, after high-temperature gas etching, was reported. The structure consisted of a periodic array of pairs of 1-bilayer-height down-steps and 5-bilayer-height up-steps. This was in contrast to conventional step-and-terrace structures, which consisted of only up, or only down, steps. It was shown that the newly observed (5–1)-bilayer-height step-and-terrace structure originated from spiral etching at a screw dislocation. A mechanism was proposed, for step-flow etching, which conserved the up-and-down step-pairs.

A New Class of Step-and-Terrace Structure Observed on 4H-SiC(0001) after High-Temperature Gas Etching. J.Suda, T.Kimoto: Applied Physics Express, 2009, 2[10], 101603