Angle‐resolved XPS depth profiling of modeled structures: testing and improvement of the method

Abstract Angle‐resolved XPS depth profiling is a useful method in surface and ultrathin film research. However, it is useful to test various modeled structures in order to get information on its ability to recognize individual sublayers and to find its resolution limits. In this paper, a model consisting of ultrathin films with sharp interfaces has been proposed and the relative intensities of XPS lines as a function of the detection angle calculated. In addition, this method has been improved by the incorporation of an attenuation of the photoelectron signal already in the layer of its origin. Using the signal obtained from the simulation of electron spectra for surface‐analysis‐based simulations as an experimental one, genetic algorithms have been used for reproducing the profiles, especially for finding its first estimates. In this way, it was possible to find the pros and cons of the angle‐resolved XPS method in the depth profiling of Co, C and SiO 2 ultrathin layers on Si substrates. Copyright © 2010 John Wiley & Sons, Ltd.