EXAMINATIONS REGARDING THE CORRECTNESS OF QUANTITATIVE SURFACE-ANALYSIS USING SNMS

For the assessment of the correctness of depth profile analyses with n on-ideal technical metal surfaces using secondary neutral particle mas s spectrometry (SNMS), the roughness of the sample surface was examine d for the transition width of the signal. It is shown that with elemen ts with low sputter rates (Al Mn), similar to that of the substrate el ement (Fe), there is no significant influence of the roughness. Howeve r, clear dependencies are observed for tin and zinc, elements with hig h sputter rates. Whereas tin gave acceptable results when the roughnes s was significant, cone formation was observed with zinc which caused abnormal sputter behaviour. The use of high-frequency sputter processe s eliminates this cone formation and leads to constant signals, even w ith thick zinc layers. This method is therefore not only suitable for use with non-conductors, as originally planned, but also offers consid erable advantages in the analysis of metal coatings.