Surface morphology and characterization of thin graphene films on SiC vicinal substrate

In this Brief Report we present a study of a 6H-SiC(0001) vicinal substrate annealed at various temperatures under ultrahigh vacuum. By combining x-ray photoelectron spectroscopy and atomic force microscopy, we investigated the morphology and the chemical surface changes accompanying the formation of graphene sheets. After annealing at 1100 degrees C step/terrace structures of the SiC substrate are clearly identified and a terrace widening is observed due to step bunching up. At 1300 degrees C approximately two graphene layers are formed and the surface steps completely disappear.