The 3D spatial resolution, the material contrast and the evolution of the noise are analyzed in the reconstructed volume of a combined scanning transmission electron microscopy (HAADF-STEM) and energy dispersive x-ray spectroscopy (EDS) tomography experiment. Standard simultaneous iterative reconstruction technique and HAADF-EDS bimodal tomographic reconstruction are considered for the +/-90° tomography series of a pillar shaped sample embedding a full nanowire device. With a high number of iterations, a spatial resolution for both HAADF and EDS down to 5 nanometer can be reached for this volume. Best material's contrast and minimum noise are obtained for medium number of iterations. Improvement of the signal-to-noise and contrast can be obtained by filtering the EDS data while the spatial resolution is not impacted. A fast and reliable preparation methodology for rectangularly shaped pillar samples for tomography analysis is discussed.

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Thermo Fisher Scientific, Eindhoven, The Netherlands
Semiconductor Science and Technology
Automated multi-modal tomography for sub-22nm IC nodes
Centrum Wiskunde & Informatica, Amsterdam (CWI), The Netherlands

Bender, H., Richard, O., Kundu, P., Favia, P., Zhong, Z., Palenstijn, W. J., … Schoenmakers, R. (2019). Combined STEM-EDS tomography of nanowire structures. Semiconductor Science and Technology, 34(11), 114002:1–114002:12. doi:10.1088/1361-6641/ab4840