Structures of sub-monolayered silicon carbide films

The electronic and geometrical structures of silicon carbide thin films are presented. The films were deposited on graphite by ion-beam deposition using tetramethylsilane (TMS) as an ion source. In the Si K-edge near-edge X-ray absorption fine structure (NEXAFS) spectra for sub-monolayered film, sharp peaks due to the resonance from Si 1s to p*-like orbitals were observed, suggesting the existence of Si=C double bonds. On the basis of the polarization dependencies of the Si 1s!p* peak intensities, it is elucidated that the direction of the p*-like orbitals is just perpendicular to the surface.We conclude that the sub-monolayered SiCx film has a flat-lying hexagonal structure of which configuration is analogous to the single sheet of graphite.