Abstract
We investigate the room temperature oxidation of Si-terminated 6H- and 4H-SiC(0001) 3×3 reconstructed surfaces by core level photoemission spectroscopy using synchrotron radiation. On both surfaces, SiO 2 formation for low oxygen exposures suggests very reactive surfaces even at room temperature. Oxygen atoms seem to react below the surface, involving carbon atoms, leading to non abrupt SiO 2 /SiC interface formation. The 4H-SiC(0001) 3×3 surface is less reactive to oxygen exposures than the 6H-SiC(0001) 3×3 one with smaller amount of SiO 2 and a less abrupt SiO 2 /SiC interface formation.