Two-hole states of the outermost surface layer studied by metastable atom electron spectroscopy Si(111)−7 × 7 and Si(100)−2 × 1

Abstract

The He ∗(2 3S) metastable atoms were shown to de-excite on the Si(111)−7 × 7 and Si(100)−2 × 1 surfaces through resonance ionization followed by Auger neutralization, producing two holes in the valence states of the outermost surface layer. A comparison between the electron emission spectra of the 7 × 7 and 2 × 1 surfaces exhibits different features which can be interpreted in terms of the surface effect, although such a difference has not been observed in ordinary L 2,3 VV Auger spectra or ion neutralization spectra.