Determination of total primary zero loss intensities in measured electron emission spectra of bare and oxidised metals - Application to aluminium oxide films on aluminium substrates

A method is presented to determine the total metallic primary zero loss (PZ L) intensity and the total oxidic PZL intensity for each core-electron leve l in measured electron emission spectra of bare and oxidised free-electron like metals land semiconductors like Si and Gel, from the resolved PZL inte nsity of only the corresponding metallic main peak and the corresponding ox idic main peak, respectively. The contribution of the intrinsic plasmon str ucture, associated with a core level metallic main peak, to the correspondi ng total metallic PZL intensity is taken into account using the intrinsic b ulk (BP) and surface (SP) plasmon excitation probabilities for the concerne d core level electron emission process in the metal. The total oxidic PZL i ntensity, as given fully by the intensity of the oxidic main peak, is obtai ned from the measured spectrum of the oxidised metal after subtraction of a reconstructed metallic main peak. Additionally, as demonstrated for the Al 2p photoemission process in the Al metal, values for the intrinsic BP and SP excitation probabilities concerned can be determined separately from the intensities of the metallic and oxidic main peaks as obtained from a serie s of measured photoelectron spectra recorded from the bare metal substrate and the metal substrate covered with a thin oxide overlayer of which the th ickness is varied. (C) 2000 Elsevier Science B.V. All rights reserved.