Volume 50, Issue 6 p. 657-666
RESEARCH ARTICLE

Improved XPS analysis by visual inspection of the survey spectrum

Sven Tougaard

Corresponding Author

Sven Tougaard

Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK 5230 Odense M, Denmark

Correspondence

Sven Tougaard, Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK 5230 Odense M, Denmark.

Email: [email protected]

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First published: 17 May 2018
Citations: 35

Abstract

In this paper, we have revisited a well-known issue in quantitative X-ray photoelectron spectroscopy (XPS) analysis: when quantitative XPS analysis is based solely on measured peak intensities, this can give rather confusing and misleading results. The problem is caused by peak intensity attenuation with photoelectron distance traveled in the sample and is an issue for samples where the atomic concentration varies substantially over the outermost ~5 nm. This is however the most significant depth range for many of the practical applications of nano-structures which is today of increasing technological importance. We discuss 3 different methods to correct for the attenuation effect and their limitations. It is then pointed out how one can, by visually comparing observed peak shapes to a set of model spectra, often get a rough idea of the atom depth distribution in the surface region of the sample. This provides a practical tool to supplement the information obtained with XPS analysis based on peak intensities and chemical state information obtained from high-resolution spectra.