RESONANCE EFFECTS IN THE NONRADIATIVE DEEXCITATION OF SILICON IN POROUS SILICON

Resonant silicon Auger KLL and 2s and 2p photoemission spectra of a po rous silicon sample have been studied when excited by photons in the e nergy domain of the Is edge in pure silicon and silicon oxide. Charact eristic features of a resonant process could be detected. In particula r, the constant initial state spectrum of the 2p state of silica behav es similarly to that encountered in systems which present a well-defin ed atomic level. This is due to the existence of a well-localized mole cular orbital built in the SiO4 unit. The use of high-energy photons, which generate high-energy electrons, allows these photoemission exper iments to be quite bulk sensitive. (C) 1998 Elsevier Science B.V. All rights reserved.