Atom probe to the limit

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Team Leader : François Vurpillot

Team members : F. Vurpillot (PR), B. Deconihout (PR), F. Danoix (CR) G. Da Costa (IR)

Atom probe is now a mature technique for the analysis of metallic materials, semiconductors and some insulators. Nevertheless, a certain number of obstacles exist which either limit the analytical performances (Spatial and Spectral Resolution, analysis yield...) or compromise the application to certain advanced research subjects (Hydrogen Analysis, application to biological materials...). This theme explores the means to push back the frontiers of the instrument, in particular by pushing further the technologies at the heart of the instrument such as new particle detection systems, or more powerful pulse generators. For example, one of the current limitations of the probe concerns its spectral characteristics (mass spectrum). The mass resolution remains insufficient to separate many elements such as nitrogen and iron in nitrided steels (Fe56++ and N2+ both with mass 28 Da), or nitrogen and silicon in semiconductor materials (Si28++ and N+, mass 14 Da), two examples of interest for the GPM. Moreover, the background noise of the detector limits the sensitivity to a few tens of ppm in the best cases. Concerning particle detection systems, several studies are being carried out simultaneously in order to increase the detection efficiency and quantitativity of local and global concentration measurements in more and more complex materials.