High resolution depth profiling of non-conducting samples with SNMS

Beat-like signal modulations in sputter depth profiles of multilayer structures are shown to enable an estimation and the optimization of the homogeneity of the sputter erosion process. Using W-Si multilayer structures of 69 doublelayers with a thickness of 40 Å, it is shown that the high-frequency mode (HFM) of electron-gas SNMS (e^–-gas SNMS) for the analysis of insulators provides the same high depth resolution as the conventional direct-bombardment mode (DBM) of this technique.