Wide (0001) terrace formation due to step bunching on a vicinal 4H-SiC (0001) epitaxial layer surface

Abstract

The wide (0001) terrace formation due to step bunching on a vicinal 4H-SiC (0001) epitaxial layer surface was investigated using low-energy electron channeling contrast (LE-ECC) imaging and atomic force microscopy. LE-ECC imaging revealed that step bunching resulted in the formation of wide atomically-flat (∼200 nm) (0001) terraces on the surface, and the terraces tended to form in pairs. Terraces in a pair had almost the same width and often showed the same LE-ECC; moreover, the contrast of the two terraces, either bright or dark, appeared to be determined by the orthogonal misorientation of substrates. On the basis of these results, the formation mechanism of the paired terraces with the same LE-ECC on a vicinal 4H-SiC (0001) surface is discussed herein.