Compositional Change of Silicon Carbide Surface due to Oxygen Adsorption and Heat Treatment

The compositional change of the 6H-SiC(100) surface was studied under heat treatment and adsorption of oxygen. X-ray photoelectron spectroscopy (XPS) was used for the analysis of the depth composition profile and chemical binding state. After heat treatment, the carbon concentration of the surface was increased due to the surface segregation of the graphite type carbon. When the adsoption of oxygen was performed with heat treatment, the carbon concentration of the surface was increased, but the amount of segregated carbon was less than that of the sample after only heat treatment. The segregated carbon seemed to react with oxygen preferentialy and to desorb from the surface as a carbon monoxide or carbon dioxide.