A common problem in depth pro®le measurement is the calibration of the depth scale. The new technique of sputter assisted electron probe microanalysis offers the possibility of calculating the composition as well as the depth scale solely from the acquired X-ray intensity data without further information, e.g. sputter rates. To achieve a depth resolution that is smaller than the depth of information of the electron probe, i.e. 0.1À1 mm, special deconvolution algorithms must be applied to the acquired data.To assess the capabilities of this new technique it was applied to a Ti/Al/Ti multilayer on Si under different measurement conditions. Quantitative depth pro®les were obtained by application of a deconvolution algorithm based on maximum entropy analysis. By comparison of these pro®les with AES depth pro®les and AFM roughness measurements, it was shown that the limiting factor to the achievable depth resolution is the occurrence of surface roughening induced by the sputtering process rather than the relatively large depth of information of the electron probe.We conclude that for certain applications sputterassisted EPMA can be regarded as a valid depth pro®ling technique with a depth resolution in the nm range.

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A solar control coating was analysed by different methods of surface analysis with respect to the layer sequence and the composition and thickness of each sublayer. The methods used for depth pro®ling were Auger electron spectroscopy, electron probe microanalysis, secondary neutral mass spectroscopy and secondary ion mass spectroscopy based on MCs . The structure of the coating was unknown at ®rst. All methods found a system of two metallic Ag layers, embedded between dielectric SnO X layers. Additionally, thin Ni-Cr layers of 1 ± 2 nm were detected on top of the Ag layers. Thus the detected layer sequence is SnO X /Ni-Cr/Ag/SnO X /Ni-Cr/Ag/SnO X /glass. The Ni:Cr ratio in the nm-thin layers could be quanti®ed by every method, the Cr fraction corresponding to less than one monolayer. We compare the capabilities and limitations of each method in routinely investigating this solar control coating. Importance was attached to an effective investigation. Nevertheless, by combining all methods, measuring artefacts could be uncovered and a comprehensive characterisation of the system was obtained.

The increasing number of energy filtering transmission electron microscopes (EFTEMs) has given many microscopists the ability to apply the fast and very efficient tool of electron spectroscopic imaging (ESI) for analytical characterisation, rather than to record EELS spectra. In a more general framework, the new ESI methods and the standard PEELS technique both aim at exploring the same three-dimensional data space. This data space is represented by the spatial co-ordinates x, y and the energy loss ΔE. The resulting intensity distribution I(x,y, ΔE) is frequently referred to as a spectrum image and the experimental techniques to acquire the corresponding data are referred to as spectrum imaging. The actual analysis can either be based on recording PEELS spectra for a twodimensional array of probe positions, or on recording series of energy filtered images across inner shell loss edges or in the low loss region.