X-ray emission study of amorphous SiO x:H films (0 ⩽ x ⩽ 2.2)

Abstract

X-ray Si K-, Si L- and O K-emission bands of a-SiO x :H alloy films are presented and compared with available UPS and XPS results on a common energy scale. With the variation of x the Si K- and Si L-emission bands undergo significant changes regarding the shape of the spectra and the position of the main features, in contrast to UPS/XPS spectra which preserve the basic shape throughout the concentration range x. We unambiguously identified all features observable in XES and UPS/XPS spectra with respect to Si 3 s, Si 3 p, O 2 s and O 2 p derived states, and we added new details to a previous UPS/XPS interpretation. Since for the system SiO x our emission bands are more sensitive to sample composition than UPS/XPS spectra we observed a non-trivial behaviour of Si p-like electrons evolving from covalent SiSi to rather ionic SiO bonds.