Relative sensitivity factors for quantitative Auger analysis of binary alloys

Abstract

Quantitative analysis by Auger electron spectroscopy is commonly performed by applying elemental sensitivity factors ( P rel) to Auger peak height data taken while sputtering. The accuracy of this approach depends on the statistical reproducibility of Auger data and variations in P rel. Recent work has identified the parameters of the Auger emission process which determine P rel. Some of these parameters are a function of concentration e.g. backscattering and escape depth. Variations in the escape depth and backscattering factor with concentration, however, are often found to affect major peaks proportionally, leaving P rel independent of composition in binary alloys. If sputtering is involved (as it usually is) variations in sputtering yields with concentration can also be significant, and a method to correct for this has also been developed. These methods have been applied to a number of binary systems of technological importance, viz. CuAu, NiAu, NiCr, FeCr, TaSi, TiO, and TiN. The accuracy of quantitative analysis is found to be ⩽ 30% using peak heights and relative sensitivity factors. Better accuracy is possible using standards in the concentration range of the unknown which are analyzed under the same experimental conditions. The relative sensitivity factor method is, however, more convenient for routine quantitative analysis and of sufficient accuracy for most applications in the thin film and silicon technologies.