Surface graphitization process of SiC(0001) single-crystal at elevated temperatures

The SiC(0001) single-crystal has been studied in terms of changes in surface composition in the temperature range of 980–1300°C by means of Auger electron spectroscopy (AES). The carbon concentration at the surface increased with temperature. This increase was split up into two processes. One was an initial fast process and the next was a slow one, observed above 1000°C. It was concluded that the former was thermodynamic and that the latter was caused by evaporation of silicon atoms. Activation energies for the slow process of surface graphitization and for evaporation of silicon, which existed in the near-surface region before heat treatment, were found to be 1.1 and 3.4 eV, respectively.