Abstract
Factor analysis and Auger electron spectroscopy (AES) were applied to study the chemical state depth profiles of TiN (100nm)/Ti (100nm) thin film layers on Si (100) substrates. Factor analysis could clearly extract the chemical state profiles of the TiN/Ti interface, which could not be resolved by the conventional Auger peak-to-peak height (APPH) measurement technique since the spectrum of TiN overlapped that of Ti. Comparison of the interface profiles obtained for three types of spectra (EN(E), dEN/dE, d2EN/dE2) showed that the differentiated spectra (dEN/dE, d2EN/dE2) were a little more suited for the factor analysis than that of EN(E) since the background effect became neglegible by differentiation. It was shown that the depth resolution Δz increased with the depth z following the well-known relation (Δz∝√z). A shape analysis of the interface profiles indicated that they were non-symmetrically skewed and the skewness increased with increasing Δz. These results clearly suggest that factor analysis is a powerful method for detailed analyses of interface profiles.
