Inelastic Low Energy Electron Diffraction Measurements of Hydrogen Adsorbed Si (001) Surfaces: 2×1:H and 1×1: :2H

We identified the monohydride phase Si(001)2×1:H and the dihydride phase Si(001)1×1: :2H by angle resolved electron energy loss profiles and I – V curves of 00-beam. For the 2×1:H-saturated surfaces, S 3 transition from back bond surface state was observed although S 1 transition from dangling bond surface state disappeared. For the 1×1: :2H surface, S 2 and S 3 transitions from back bond surface states completely disappeared but S 1 transition was observed. We clearly distinguished hydrogen induced loss peaks for the two surfaces: the peaks were at 8 eV for the 2×1:H surface and at 7 eV for the 1×1: :2H surface.