Contribution of elastic photoelectron scattering to the shape of the measured XPS intensity in-depth profile



The in-depth profiles obtained from Auger electron spectroscopy or X-ray photoelectron spectroscopy (XPS) experiments are known to differ from an actual concentration profiles due to limitations of surface-sensitive techniques, e.g. finite sampling depth, or atomic mixing during sputtering. However, the monitored signal intensities are also affected by elastic scattering of signal electrons. Calculations performed for idealized multilayer structures indicate that elastic scattering of photoelectrons may significantly influence the in-depth signal intensity. In the present work, an attempt is made to evaluate the contribution of elastic photoelectron scattering to measured signal intensity profile for samples with diffused interfaces. The in-depth profile measured for the 5x(Au/Ni)/Si multilayer structure has been submitted to this analysis. A relatively simple procedure to evaluate the contribution of elastic scattering to the profile shape has been proposed. The effect of elastic scattering is found to be a reduction of the XPS intensity by 5–10% in the investigated cases. Copyright © 2014 John Wiley & Sons, Ltd.