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.

EDS tomography, HEBT tomography reconstruction, nanowire device, pillar tomography sample, STEM tomography
Thermo Fisher Scientific, Eindhoven, The Netherlands
Semiconductor Science and Technology
Centrum Wiskunde & Informatica, Amsterdam, 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). doi:10.1088/1361-6641/ab4840