INCORPORATION OF SURFACE-TOPOGRAPHY IN THE XPS ANALYSIS OF CURVED OR ROUGH SAMPLES COVERED BY THIN MULTILAYERS

Approaches are described for the analysis of XPS signals from samples comprising thin conformal coatings on substrates with non-ideal surfac e topography, In particular, attention is focused on arbitrarily shape d rough or curved substrates. Relations are derived for the relative x -ray photoelectron intensities emitted from various elements in such n on-ideal samples, The surface topography of arbitrarily rough samples is analysed by atomic force microscopy to provide a frequency histogra m of the local slopes, which is incorporated into a global, multi-elem ent analysis method for interpretation of the observed XPS elemental i ntensities, An analogous approach is used for the analysis of curved s amples, Our algorithms also enable simultaneous analysis of successive ly coated multilayer structures, When the elemental composition of the individual layers is known, the fit procedure enables determination o f the thickness values of single-layer and multilayer coatings, The ra nge of validity of the theory is discussed, (C) 1997 by John Wiley & S ons, Ltd.