Transmission-electron-microscopy observations on the growth of epitaxial graphene on 3C-SiC(110) and 3C-SiC(100) virtual substrates

By conducting a heteroepitaxy of a 3C-SiC film on a Si substrate and by annealing its surface in a UHV ambient, epitaxial graphene can be formed on such 3C-SiC virtual substrates. While the growth on the Si-terminated 3C-SiC(111)/Si(111) surface is known to proceed in a similar manner as on the Si-terminated 6H-SiC(0001) surface, successful growth of graphene on 3C-SiC(100)/Si(100) and 3C-SiC(110)/Si(110) surfaces remains puzzling. We have carried out detailed cross-sectional transmission-electron-microscopy observations on these systems to find out that (111)-facets may play crucial roles in the initiation of graphene on these surfaces. This observation also accounts for the absence of the interface layer at the graphene/SiC in these orientations.