Quantifying data from Auger spectra and images

Abstract

Abstract A method for quantifying Auger spectra and including matrix effects is described. This method corrects iteratively for the effects of electron back‐scattering, the inelastic mean free path and atomic density in the sample using established methods. New algorithms have been developed to assist the user interactively with the analysis of spectra collected from surfaces covered by thin films of unknown composition or thickness, or by coverage of another material. Error analysis has been included for both homogeneous and thin film cases. A ‘figure of merit’, used to inform the user if a thin film model of the surface is accurate, is introduced. The algorithms can be implemented on a small microcomputer. Their application to quantitative Auger analysis by multi‐spectral imaging is also described. Each point in a set of images has been corrected for the factors that influence the Auger current to arrive at surface compositions at each pixel for each element. Some of the advantages and problems of quantifying Auger images will be outlined. The use of multi‐spectral Auger images is seen as a powerful means of identifying surface phases of materials and is given the acronym MULSAM— MUL ti‐ S pectral‐ A uger M apping.