Yields, sensitivities, and natural line shapes of Auger lines. I. Ag, Si, Al, Mg, and Cu

Abstract

With the commonly available analyzer resolution in Auger electron spectroscopy (AES) measurements, the Auger line shapes can be greatly distorted and large errors can be incurred in the measured signal intensities. In view of this, a universal relation was previously derived whereby the experimentally measured line intensities can easily be corrected so as to yield, to a good approximation, the intensities that would have been measured were the resolution infinitely good. In this paper we present high-resolution measurements of the natural line shapes of several Auger lines. Based on the intrinsic linewidths derived from these measurements, we demonstrate the validity of our correction procedure by measuring Auger sensitivities with different resolutions. Whereas the as-measured sensitivity for each element studied varies appreciably as the resolution is changed, the corrected sensitivity remains constant, in most cases to within 10%–20%, independently of resolution. The corrected sensitivities provide good estimates for the true sensitivities, and a compilation of their values is given in tabular form. It is these sensitivities that any theoretical calculations of Auger yields should be compared with. We show here that using the as-measured sensitivities for such a comparison can be grossly misleading, by as much as a factor of 100. Also, the quantitative determination of atomic concentrations becomes more accurate when the measured signal intensities are corrected and the analysis is based on the corrected sensitivities.