Initial Stages of the Graphite-SiC(0001) Interface Formation Studied by Photoelectron Spectroscopy

摘要

Graphitization of the 6H-SiC(0001) surface as a function of annealing temperature has been studied by ARPES, high resolution XPS, and LEED. For the initial stage of graphitization -the 6 3~(1/2) reconstructed surface - we observe σ-bands characteristic of graphitic sp~2-bonded carbon. The π-bands are modified by the interaction with the substrate. C1s core level spectra indicate that this layer consists of two inequivalent types of carbon atoms. The next layer of graphite (graphene) formed on top of the 6 3~(1/2) surface at T_A=1250°C-1300°C has an unperturbed electronic structure. Annealing at higher temperatures results in the formation of a multilayer graphite film. It is shown that the atomic arrangement of the interface between graphite and the SiC(0001) surface is practically identical to that of the 6 3~(1/2) reconstructed layer.