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ZB 19 - Characterization of processes in first atomic layers of a solid surface (A.Jablonski)


Metrology of Quantitative Surface Analysis by Electron Spectroscopies. A. Jablonski, L. Zommer

The main field of interest is the theoretical basis of Auger electron spectroscopy (AES) and photoelectron spectroscopy (XPS). Current studies consist in introduction of new parameters describing the electron transport in formalism of both techniques, in developing of new methods for determination of these parameters, and edition of databases providing these parameters. In consequence, these studies are improving accuracy of quantitative analysis by above electron spectroscopies.
    The considered techniques, AES and XPS, make possible the identification of elements present in the surface region of a solid. The XPS spectrum recorded for the AuAgCuPd alloy, and an example of such analysis is shown below. It consists in identification of peaks visible in the spectrum. Qualitative analysis is presently a routine procedure providing information on elements present (or chemical compounds).
 Although the surface sensitive spectroscopies, AES and XPS, are developed since early 1970s, the quantitative analysis of surface still is a major scientific challenge. Derivation of such information of high accuracy from intensities of observed peaks is still a major scientific challenge.
     Research associated with quantification of electron spectroscopies is conducted in cooperation with National Institute of Standards and Technology (NIST) in USA. The databases containing parameters needed for quantitative surface analysis, edited within this cooperation, are currently recommended and distributed by NIST.
    Research is also devoted towards new parameters describing electron transport. Some of the parameters proposed in the past (the mean electron escape depth, the emission depth distribution function, and the effective attenuation length) have become the accepted international standards supported by the relevant organizations: ISO (International Standard Organization) and ASTM (American Society for Testing and Materials). Results of this research are very well cited in the literature.