The determination of oxide film thickness and composition on indium and chromium by decomposition of auger electron spectra

The thickness and composition of thin oxide films on indium and on chromium have been obtained from their Auger electron spectra by a technique developed to decompose overlapping spectral peaks. In the first case, the spectral peak from an indium metal substrate is separated from the indium peak from an In 2O 3 surface film, so that the thickness of the oxide film can be ascertained. A similar separation in the second system shows that a gross error in the Cr content of the oxide is obtained if the spectrum is not decomposed before the Cr content is calculated. The only assumption in the decomposition technique is that the experimental spectrum can be described by a linear combination of the standard spectra of its components.