Initial stages of graphitization on SiC(000-1), as studied by phase atomic force microscopy

The initial stages of graphitization on 4H- and 6H-SiC (000-1) under ultrahigh vacuum at temperatures of 1125–1175°C have been studied by atomic force microscopy (AFM), X-ray photoemission spectroscopy and reflected high energy electron diffraction. A progressive coverage of the surface by graphene has been observed depending on the time and temperature of annealing. Graphene growth mainly starts from the step edges, although it sometimes nucleates in the middle of a SiC terrace. Comparison of the topographic and phase AFM images shows that the latter are the most efficient for identifying graphene before complete coverage of the surface.