Fluorescence-based photoelectron features in Auger spectra

Abstract

The use of energetic (≥10 keV) electron beams in Auger electron spectroscopy is becoming more and more standard practice because of their superior focusability and an accompanying reduction in charging problems when inspecting thin (<1 µm) insulating layers on conductive substrates. Such beams, however, have a much greater probability to excite (x‐ray) fluorescence, which, in turn, may liberate characteristic photoelectrons. The occurrence of thus‐formed spurious peaks in Auger spectra is not generally acknowledged as a possible or probable artefact that may lead to erroneous assignments. A series of measurements has been made, mainly on silicon technology‐based materials, to establish the importance of this phenomenon. From an analysis of the data, a crude estimate of the occurrence probability and magnitude of fluorescence‐induced photoelectron excitation can be given. Copyright © 2000 John Wiley & Sons, Ltd.