Peak resolving of complex Auger spectra by least-squares fitting with prefiltering of spectra: An application to depth profiling

In Auger electron spectroscopy (AES), the filter-fit method, which was developed originally for the analysis of energy dispersive x-ray spectra, is applied to resolve overlapped peaks in the presence of continuum background, using the least-squares fitting (LSF) procedure after the prefiltering of spectra. With the filter-fit method, the background is first suppressed by filtration with a proper digital filter, and then the filtered complex Auger peaks are resolved by LSF calculation using filtered reference peaks. The analysis accuracy improves greatly over the conventional method because the disturbance by the background is minimized. A new depth compositional analysis routine providing the filter-fit procedure was successfully applied to the analysis of a thin TiN layer deposited on a glass substrate, in which both Ti and N profiles were obtained separately, though the two peaks overlapped each other.