Evaluation of Auger Electron Spectroscopy (AES) depth-profiles by application of Factor Analysis

Summary AES is a useful tool in order to determine the quantitative composition of a solid surface. Conventional methods of evaluating AES concentration profiles leave chemical information about the bonding state of an element contained in the spectra unused. To extract these Factor Analysis (FA) was employed as a mathematical technique to form a physical model of the composition of a sample. With FA the correlation function between the measured spectra is evaluated. Thus it is possible to determine number and quantity of chemical components influencing the data. The feasibility of FA is demonstrated by its application to the evaluation of AES concentration profiles. We investigated in some detail heterostructures consisting of a Si₃N₄/-Si:H/SiO₂ and Ti/Si Schottky contacts on Si substrates, respectively.