SEPARATION OF SPECTRAL COMPONENTS AND DEPTH PROFILING THROUGH INELASTIC BACKGROUND ANALYSIS OF XPS SPECTRA WITH OVERLAPPING PEAKS

A method for simultaneous separation and quantitative analysis of overlapping XPS spectral components originating from two different elements has been developed. The method is based on a detailed theory for electron transport in solids and involves deconvolution of the inelastic spectral background from the surface electron spectra. The method is tested through analysis of model spectra of adsorbate/substrate systems following the Frank-van der Merwe, the Stranski-Krastanow or the Volmer-Weber modes of growth. It is demonstrated that the total amount of adsorbate can be found from one single spectrum with an error of less-than-or-equal-to 10% independent of the mode of growth. In addition, the method gives information on the structural properties of the adsorbate and its mode of growth, with a resolution of the order of the inelastic mean free path.