Decay Processes of Si 2s Core Holes in Si(111)-7 x 7 Revealed by Si Auger Electron Si 2s Photoelectron Coincidence Measurements

Decay processes of Si 2s core holes in a clean Si(111)-7 x 7 surface are investigated using coincidence measurements of Si Auger electrons and Si 2s photoelectrons at a photon energy of 180 eV. We show that Si 2s core holes exhibit two nonradiative decay processes: the first being a Si ... Coster-Kronig transition followed by delocalization of the valence hole and Si L23VV Auger decay, and the second being Si L1VV Auger decay. The branching ratio of the Si ... Coster-Kronig transition to the Si L1VV Auger decay is estimated to be 96.7% ± 0.4% to 3.2% ± 0.4%. (ProQuest: ... denotes formulae/symbols omitted.)