Background correction in XPS: Comparison of validity of different methods

Publisher Website
Google Scholar
Abstract
We investigate the validity of methods for background correction in XPS by comparing determined peak intensity ratios with theory. For Ag, Pt and Au, peaks are considered for which possible errors in the inelastic electron mean free path and in the energy dependence of the analyser response function have minimal influence on the accuracy of the theoretical ratios. The straight line method gives a root‐mean‐square (RMS) deviation from theory of ∼34% and ∼60% when the low‐energy point is selected to lie close to or far from the main structure of the peak respectively. The Shirley method gives an RMS deviation from theory of ∼35%, with only a small change between two sets of considered energy ranges. The Tougaard method gives an RMS deviation from theory of ∼3%, which is of the order of the expected uncertainty due to the combined effects of the level of the apparatus stability and the errors in the ratios of photo‐ionization cross‐sections.