Photoemission study of the Si02/Si interface structure of thin oxide film on vicinal Si(100) surface

The Si02/Si interface structure of thin oxide films thermally grown on vicinal Si(100) surfaces with the surface normal inclined at small angles with respect to [100] toward [001], has been investigated using high-resolution core-level photoemission spectroscopy with synchrotron radiation. Photoemission data suggest that as a result of the thermal oxidation Si(111) and (110) facets are favorably generated at the Si02/Si interface on the vicinal Si (100) surfaces. It is also suggested that an ordered phase of Si02 is present on the interfacial Si (111) facets. The generation of this phase is found to strongly depend on the inclination angle of the substrate surface to the (100) plane. This dependence is interpreted in terms of the variation in the density of interfacial Si (111) facets with the inclination angle.