Contribution of intrinsic and extrinsic excitations to KLL Auger spectra induced from Ge films

• Published in: Journal of electron spectroscopy and related phenomena 2004-04, Vol.135 (2), p.177-182
• Main Authors: Berényi, Z, Kövér, L, Tougaard, S, Yubero, F, Tóth, J, Cserny, I, Varga, D
• Format: Article
• Language: English
• Subjects: Auger spectroscopy; Inelastic mean free path; Inelastic scattering; X-ray photoelectron spectroscopy
• ISSN: 0368-2048; 1873-2526
• DOI: 10.1016/j.elspec.2004.03.005

Earlier studies on Ge KLL Auger spectra photoexcited from thin films or emitted from thin layer radioactive sources showed a strong satellite of the main 1 D 2 peak. This was interpreted as a consequence of inelastic scattering of electrons in these systems. Similar intense satellites were observed in Ge 1s photoelectron spectra. To clarify the origin of these satellites, Ge KL 23L 23 spectra were induced from polycrystalline Ge films of 100 nm thickness, using bremsstrahlung radiation. The KLL Auger spectra were measured with high energy resolution by a high energy electron spectrometer based on a hemispherical analyzer. Correction of the experimental spectra for inelastic background was performed using experimental cross-sections for inelastic scattering of electrons, obtained from our high energy resolution REELS measurements applying Tougaard’s method. The measured and background corrected spectra are compared to model spectra calculated within the frame of a theory developed by Yubero and Tougaard to describe both extrinsic and intrinsic losses in XPS experiments. On the basis of the comparison between our experimental and model spectra, the strong satellite is attributed to plasmon losses. Our analysis of the experimental spectra indicates a significant (∼30%) contribution of intrinsic plasmon losses, in reasonable agreement with the prediction of the theory.