In situ Reflection High-Energy Electron Diffraction observation of graphene layer formation on 6H-SiC Substrate

Evolutions of diffraction patterns of 6H-SiC(0001) surface during graphene growth have been studied. Characteristic features of diffraction pattern evolutions during morphological transformations from an initially rough 6H-SiC(0001) surface to a step-terraced one with subsequent formation of a buffer carbon layer on it and, finally, epitaxial graphene induced by thermal annealing were determined. Using ex situ atomic force microscopy, scanning electron microscopy and Raman shift spectroscopy methods, morphology, stoichiometric composition and degree of surface perfection of the samples were found to correspond to observed diffraction patterns obtained at the corresponding stages of graphene growth.