Composition profile broadening in the sputtering of thin layers

The sputter broadening effect in composition profiling (e.g. with AES or SIMS) can be expressed by the concept of depth resolution, which is generally defined referring to the sputtering through a sharp interface of two components. It is shown how the shape alteration of the composition profile of a thin sandwich layer can also be used as a measure of depth resolution in terms of original layer thickness and measured FWHM. AES measurements with Cr layers in a Ni matrix and comparison with those of other authors show the validity of the proposed model which leads to limitng sputter depths for the detection of very thin layers. (Auth.)