Ž . Applied Surface Science 144–145 1999 173–177 Experimental determination of the inelastic mean free path of electrons in GaSb and InSb G. Gergely a, ) , A. Sulyok a , M. Menyhard a , J. Toth b , D. Varga b , A. Jablonski c , M. Krawczyk c , B. Gruzza d , L. Bideux d , C. Robert d a Res. Inst. Technical Phys. Mat. Sci., PO Box 49, H-1525 Budapest, Hungary b ATOMKI, PO Box 51, H-4001 Debrecen, Hungary c Institute of Physical Chemistry, Polish Academy of Science, 01-224 Warsaw, Poland d LASMEA, UMR CNRS 6602, Blaise Pascal UniÕ., 63177 Aubiere, France Abstract Ž . The inelastic mean free path IMFP of electrons is a fundamental material parameter for quantitative surface- and thin-film analysis by AES and XPS. Experimental determination of IMFP is based on the elastic peak electron spectroscopy Ž . EPES The intensity of the elastic peak recorded for the sample is compared with that of the Ni reference. The IMFP is Ž . evaluated from the Monte Carlo MC calculations of the elastic backscattering probability. The MC algorithm is based on elastic scattering cross-sections from the NIST 64 database and IMFP values of Ni. Experiments have been carried out in three laboratories working with different types of electron spectrometers and energy ranges: HSA, E s0.2–5 keV; CMA, Ž . Ž . E s0.2–2 keV, and RFA, E s0.2–1.5 keV. GaSb 100 and InSb 100 samples have been cleaned and their surface layer amorphized by an Ar q ion bombardment at E s2 keV. The surface composition after cleaning was checked in situ by ion XPS. No metallic Ga, In or Sb phases were evidenced by plasmon losses on the surface after E s2 keV Ar q ion ion treatment. The MC calculations were based on the real surface composition. Thus, the IMFP values experimentally obtained for the ion bombarded samples can be considered as the volume parameters for E )0.5 keV. A reasonable agreement was found with the calculated IMFP data of NIST and with other theoretically determined values of the IMFP. q 1999 Elsevier Science B.V. All rights reserved. PACS: 7920K Keywords: Inelastic mean free path; Elastic scattering 1. Introduction Ž . The inelastic mean free path IMFP of electrons is a fundamental physical parameter used in quantita- tive electron spectroscopy, surface physics and anal- ) Corresponding author. Tel.: q36-1-395-9220; Fax: q36-1- 395-9284; E-mail: gergely@mfa.kfki.hu ysis. Abundant literature is available on the calcu- w x lated IMFP values of elements 1–3 and binary w x compounds 4–6 . Experimental determination of the IMFP is rather difficult. Elastic peak electron spec- w x wx troscopy 7,8 proved to be a practical method 9 . It Ž. is based on the elastic peak I intensity ratio I rI s r Ž . of the sample subscript s with respect to a refer- Ž . ence subscript r standard. Nowadays, Ni is used 0169-4332r99r$ - see front matter q 1999 Elsevier Science B.V. All rights reserved. Ž . PII: S0169-4332 98 00793-4