Advances in the reconstruction of atom probe tomography data

Key to the integrity of atom probe microanalysis, the tomographic reconstruction is built atom by atom following a simplistic protocol established for previous generations of instruments. In this paper, after a short review of the main reconstruction protocols, we describe recent improvements originating from the use of exact formulae enabling significant reduction of spatial distortions, especially near the edges of the reconstruction. We also show how predictive values for the reconstruction parameters can be derived from electrostatic simulations, and finally introduce parameters varying throughout the analysis.

Research Highlights
► The main reconstruction protocols described in the literature are reviewed.
► A new protocol, similar to the one recently proposed by Geiser et al. is described.
► The integrity of reconstructions built using these various methods is tested against simulated and experimental data sets, highlighting the importance of an accurate determination of the projection law.
► Finite-element method simulations are used to estimate the image compression factor.
► Finally, the limitations of a global approach to describe the ion projection in atom probe tomography is discussed in light of the very local changes in specimen shape revealed by observation of the point-density on the detector.