Experimental determination of the inelastic mean free path of electrons inGaP and InAs

The inelastic mean free path (IMFP) of electrons is a fundamental material parameter needed for surface analysis. The IMFP data of semiconducting III- V compounds have been calculated by Tanuma st al,, Kwei et al., and Cries, The present paper completes previous research and reports experimental stud ies on the IMFPs of Gap and InAs, Elastic peak electron spectroscopy (EPES) was used with Ni, Au and Ag reference samples. Both InAs(100) and GaP(100) have been studied in three laboratories, using different types of electron spectrometer analysers and energy ranges: HSA (0.2-5 keV), DCMA (0.2-2 keV ), DESA 100 (0.5-2 keV), The surface of the samples was cleaned and amorphi zed by Ar+ ion bombardment with controlled parameters (energy, dose, etc.) to eliminate crystallinity effects. The surface composition of the ion-bomb arded samples was determined in situ by XPS and Auger electron spectroscopy . Their crystallinity and incoherent elastic scattering were tested with Re nninger plots of the elastic peak intensity, rotating the sample around its axis perpendicular to the surface. The IMFPs were calculated by a Monte Ca rlo algorithm using the NIST database of elastic scattering cross-sections. A reasonable agreement was found with theoretical IMFP values calculated b y other authors. Copyright (C) 2000 John Whey & Sons, Ltd.