Initial oxide/SiC interface formation on C-terminated β-SiC(100) c(2×2) and graphitic C-rich β-SiC(100) 1×1 surfaces

Abstract

We investigate the initial interface formation of oxide/C-terminated β-SiC(100) c(2×2) and oxide/C-rich β-SiC(100) 1×1 surfaces by Si 2p and C 1s core level photoemission spectroscopy using synchrotron radiation. Contrary to the Si-rich SiC surfaces, the C-terminated and C-rich surfaces are much less reactive to oxygen, with much higher exposures and temperatures required to grow a significant amount of oxides. This leads to nonabrupt oxide/SiC interface formation including predominantly mixed oxide products containing carbon species, with marginal amounts of SiO2 only. The lack of dangling bonds on the surface together with the C plane and/or graphitic species limiting oxygen insertion into the SiC lattice are likely at the origin of this very different behavior when compared to Si-rich SiC surfaces.