Wide scale surface measurement using white light interferometry and atomic force microscopy

A variety of technical applications require surface roughnesses to be measured and characterised over a wide range of scale. In order to meet these requirements it is inevitable to combine different measurement techniques by using an assembled PSD. As an example the white light interferometry (WLI) is compared to the atomic force microscopy (AFM) by measuring a binary grating. The results show a good correspondence of the profiles and power spectral densities (PSD). Furthermore, rough surfaces are measured by WLI and AFM and combined by means of the PSI in a wide range of scale covering up to 5 orders of magnitude. It will be shown, that in some cases only the combined PSD will give the right results to describe the surface by a model PSD. It turns out that either the fractal or the ABC-model are very well suited.