Metastable-Atom Auger Deexcitation Spectroscopy of Clean and Oxygen-Covered Si(111) Surfaces

Abstract
The energy distribution of electrons emitted from clean and oxygen-covered Si(111) surfaces upon impact of metastable He*atoms was measured. The metastable deexcitation at the clean Si(111) surface was shown to occur predominantly via Auger deexcitation mechanism: He*+S→He+S++e- (S: surface). The adsorption process was monitored by this technique with a high sensitivity to the outermost atomic layer. Differences between the present metastable-atom deexcitation spectra and previous photoemission spectra are discussed.