Growth of well-ordered silicon dioxide films on Mo(112)

摘要

A preparation is reported which, for the first time, results in a thin, crystalline SiO_2 film on a Mo(112) single crystal. The procedure consists of repeated cycles of Si deposition and subsequent oxidation, followed by a final annealing procedure. LEED pictures of high contrast show a hexagonal, crystalline SiO_2 overlayer with a commensurate relationship to the Mo(112) substrate. AES and XPS have been used to control film stoichiometry. A spatial dependence of the Si~4+ core level shift with distance from the interface plane is observed, but the shift is found to be essentially insensitive to the degree of crystallinity in the film. The wetting of the substrate by the film has been investigated by LEED, XPS and TDS. The results prove that the film covers the substrate completely.