SEM and ECC imaging study of step-bunched structure on 4H-SiC epitaxial layers

摘要

Summary form only given. The complete presentation was not made available for publication as part of the conference proceedings. Step bunching on a vicinal 4H-SiC (0001) epitaxial layer surface was investigated using low-voltage scanning electron microscopy (LVSEM) and low-energy electron channeling contrast (ECC) imaging. LVSEM observations revealed that the step bunching resulted in the formation of atomically flat wide (∼250 nm) terraces on the surface, and the terraces tended to form in pairs. The two terraces in paired terraces often showed the same electron channeling contrast as each other, and 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 step-bunched structure on a vicinal 4H-SiC (0001) surface is discussed.