AVS 51st International Symposium
    Applied Surface Science Wednesday Sessions
       Session AS-WeM

Paper AS-WeM4
Algorithm for Improved XPS-Imaging

Wednesday, November 17, 2004, 9:20 am, Room 210A

Session: Chemometric Analysis of Spectral or Image Data; XPS/TOF-SIMS Applications
Presenter: S. Tougaard, University of Southern Denmark
Correspondent: Click to Email
Non-destructive XPS-imaging of surfaces is based on analysis of peak intensities. It is however well known that XPS-quantification from the peak intensity leads to huge uncertainties because the measured intensity depends strongly on the depth distribution of atoms. The problem was basically solved by developing models for the detailed analysis of the energy distribution of emitted electrons leading to algorithms summarized in.@footnote 1@ The validity of these algorithms have been extensively tested experimentally and found to be able to accurately determine both the quantitative amount of atoms as well as their in-depth distribution within the outermost ~ 5-10 nm of surfaces. Practical application of these algorithms has increased after ready to use software packages were made available and they are now used in labs worldwide. These software packages are easy to use but they need operator interaction. They are not well suited for automatic data processing and there is a need for simplified strategies that can be automated and used in e.g. XPS-imaging where the huge amount of data hinders manual data analysis. In this paper we study a very simple algorithm that automatically takes the XPS-peak attenuation effect into account@footnote 2@. The algorithm is less accurate than those in@footnote 1@ but it is substantially more accurate than using peak intensities and it is well suited for automation. It gives the amount of atoms within the outermost ~ 3IMFP with a good accuracy and it gives also a rough estimate for the in-depth profile. In the talk, the validity of the simple algorithm is tested on several experimental systems and the results are compared to analysis of the same samples quantified by more accurate methods. The algorithm seems promising for significant improvements in XPS-imaging. @FootnoteText@ @footnote 1@ S. Tougaard, J. Vac. Sci. Technol. A14, 1415 (1996); see also www.quases.com@footnote 2@ S. Tougaard, J. Vac. Sci. Technol. A21, 1081 (2003).