The development of surface shape during sputter‐depth profiling in Auger electron spectroscopy

Ion bombardment is an important process in surface analysis, not only for surface cleaning, but also for obtaining composition‐depth profiles through thin films and interfaces. Although the use of depth profiling is well established for initially flat surfaces and the problems associated with ion‐induced artefacts such as surface topography, preferential sputtering and redeposition are well recognized, the additional problems which occur when non‐flat surfaces are bombarded have been neglected. For example, depth profile analysis of rods, wires, fibres, etc., using Auger electron spectroscopy is now of interest for many commercial purposes. However, the erosion of such geometries is non‐uniform since different angles of incidence are presented to the incoming ion beam. In this paper, computer simulations are presented which illustrate the erosion of such geometries and a quantitative analysis is given for the resulting degradation in depth resolution as a function of sample and electron beam diameter.