Initial oxidation of Si(311) surfaces studied by high-resolution electron energy loss spectroscopy

Surface reactions of Si(311) surfaces with hydrogen, oxygen, and water have been investigated by high-resolution electron energy loss spectroscopy (HREELS). The structure ofSi(311)-3 × 1clean surfaces is transformed to a1 × 1structure by exposure to atomic hydrogen and H-terminated Si(311) surfaces are stable against the O2 adsorption at room temperature. On the other hand, the H2O-adsorbed surface have a3 × 1structure, and H2O molecules are considered to adsorb dissociatively only on the dangling bonds of dimer atoms but not on those of step-site atoms. The experimental data suggests that the step-site atoms on the(311)-3 × 1surface are stabilized against the H2O and O2 adsorption.