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Fitting the inelastic tail below experimentally observed Auger peaks
A153 Cu and W are reported and show good agreement with previous Monte Carlo calculations. The use of Auger spectra from self- and substrate-supported regions of the film to test pragmatic solutions for the isolation of an Auger peak in AES is also demonstrated. This method can be used to study the causes of the background in AES. Further it could also be used in the study by AES of radiation or heat sensitive materials deposited on a thin C film.
884
Surface Science 152/153 (1985) 884-894 North-Holland, Amsterdam
A COMPARISON NEUTRON
OF
ELECTRON
TRANSPORT
V.M. DWYER
TRANSPORT
IN AES/PES
WITH
THEORY
and J.A.D. MATTHEW
University of York, Heslington, York Y01 5DD, UK Received 3 April 1984 The Boltzmann equation represents the standard theory for particle transport in random media. It is thus applicable to Auger/photo electrons in polycrystalline solids. In this paper we compare the convential Auger/PES theory, which neglects angular deflection of the emitted electrons, with two scattering models which have been found to be useful in Reactor physics. We find that the conventional Auguer yield formula ~rn(6)= (Nhi/4~r)cos 6 holds approximately qualitatively, but not quantitatively. We also find that, in keeping with Monte Carlo calculations, there is a substantial alteration to the mean depth of analysis relative to the no-scattering model.
Surface Science 152/153 (1985) 895-901 North-Holland, Amsterdam
895
FITI'ING THE INELASTIC TAIL BELOW EXPERIMENTALLY
OBSERVED AUGER PEAKS D.C. PEACOCK
Department of Physics, Unioersity of York, Heslington, York Y01 5DD, UK Received 27 March 1984; accepted for publication 24 April 1984 A new iterative procedure enabling the extraction of Auger and associated loss peaks from the secondary electron spectrum N(E) is described and demonstrated. Sections of N(E) away from Auger and loss features are approximated by a cascade of the form A E - " where m is predicted to be unity. For a wide range of elements, experimental values of m above an Auger peak in energy are found to be less than the theoretical value. After subtraction of the cascade, the step-like feature found beneath the Auger peak and arising from inelastically scattered Auger electrons is calculated. Unlike methods described previously, the procedure described here has the advantage that the fitted tail is forced to closely follow the spectrum below the Auger and loss features in energy. The ratio of the stripped peak area to the increase in background associated with the peak is calculated for the samples used in this study and the prospects of using this ratio for non-destructive depth profiling are discussed.
884
Surface Science 152/153 (1985) 884-894 North-Holland, Amsterdam
A COMPARISON NEUTRON
OF
ELECTRON
TRANSPORT
V.M. DWYER
TRANSPORT
IN AES/PES
WITH
THEORY
and J.A.D. MATTHEW
University of York, Heslington, York Y01 5DD, UK Received 3 April 1984 The Boltzmann equation represents the standard theory for particle transport in random media. It is thus applicable to Auger/photo electrons in polycrystalline solids. In this paper we compare the convential Auger/PES theory, which neglects angular deflection of the emitted electrons, with two scattering models which have been found to be useful in Reactor physics. We find that the conventional Auguer yield formula ~rn(6)= (Nhi/4~r)cos 6 holds approximately qualitatively, but not quantitatively. We also find that, in keeping with Monte Carlo calculations, there is a substantial alteration to the mean depth of analysis relative to the no-scattering model.
Surface Science 152/153 (1985) 895-901 North-Holland, Amsterdam
895
FITI'ING THE INELASTIC TAIL BELOW EXPERIMENTALLY
OBSERVED AUGER PEAKS D.C. PEACOCK
Department of Physics, Unioersity of York, Heslington, York Y01 5DD, UK Received 27 March 1984; accepted for publication 24 April 1984 A new iterative procedure enabling the extraction of Auger and associated loss peaks from the secondary electron spectrum N(E) is described and demonstrated. Sections of N(E) away from Auger and loss features are approximated by a cascade of the form A E - " where m is predicted to be unity. For a wide range of elements, experimental values of m above an Auger peak in energy are found to be less than the theoretical value. After subtraction of the cascade, the step-like feature found beneath the Auger peak and arising from inelastically scattered Auger electrons is calculated. Unlike methods described previously, the procedure described here has the advantage that the fitted tail is forced to closely follow the spectrum below the Auger and loss features in energy. The ratio of the stripped peak area to the increase in background associated with the peak is calculated for the samples used in this study and the prospects of using this ratio for non-destructive depth profiling are discussed.