Surface reactions of 6H–SiC(0 0 0 1)3 × 3 with oxygen molecules at various temperatures

The initial reactions of the 6H–SiC(0 0 0 1)3 × 3 surface with oxygen molecules at elevated temperatures have been investigated using scanning tunneling microscopy. It has been revealed that the 3 × 3 surface maintained the original structural ingredients under room temperature (RT) oxidation. Upon O2 exposure at 500 °C, the oxygen-inserted sites activated the preferential oxidation of the neighbor sites forming domains, which were subsequently transformed into a disordered area after further O2 exposure. After O2 exposure at 700 °C, the surface Si atoms were etched, resulting in the formation of the 23 × 213 surface phase.