EFFECTS OF ELASTIC AND INELASTIC ELECTRON-SCATTERING ON QUANTITATIVE SURFACE-ANALYSES BY AES AND XPS

A review is given that describes the complications due to elastic and inelastic electron scattering in quantitative surface analyses by Auger-electron spectroscopy and x-ray photoelectron spectroscopy. Four principal topics are addressed. First, the simple formulae for surface analyses are based on a model that ignores elastic scattering. Recent work assessing the effects of elastic scattering is summarized which shows that the simple formulae are valid in certain analytical situations but with an appropriate choice of the parameter describing inelastic scattering. Second, we review measurements of effective attenuation lengths and point out many sources of significant systematic error in these measurements. Third, we describe recent calculations of inelastic mean free paths (IMFPs) in over fifty materials that have been utilized to develop a predictive IMFP formula. Finally, we discuss the complicating effects of inelastic scattering on reliable measurements of AES and XPS intensities.