Regensburg 2022 – wissenschaftliches Programm

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DS: Fachverband Dünne Schichten

DS 1: Thin Film Properties: Structure, Morphology and Composition (XRD, TEM, XPS, SIMS, RBS, AFM, ...) 1

DS 1.5: Vortrag

Montag, 5. September 2022, 10:30–10:45, H14

Contrast modes in transmission experiments using broad and focussed keV ion beams — •Svenja Lohmann^{1, 2}, Gregor Hlawacek¹, Radek Holeňák², Nico Klingner¹, Daniel Primetzhofer², and Eduardo Serralta^{1, 3} — ¹Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany — ²Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden — ³Technische Universität Dresden, Germany

The helium ion microscope (HIM) is an instrument for high-resolution imaging, composition analysis, and materials modification at the nanoscale. Ion transmission experiments could further improve the analytical capabilities of this technique, and multiple contrast modes are possible. We explore the latter at keV ion energies using a HIM in a scanning transmission approach as well as a broad beam in combination with a time-of-flight (ToF) set-up. Both systems employ position-sensitive detectors allowing for analysis of angular distributions.

In the ToF-system, we find a strong trajectory-dependence of the measured specific energy loss attributed to charge-exchange events in close collisions [Phys. Rev. Lett. 124 (2020), 096601]. Channelling and blocking of transmitted ions allows for mapping of intensity as well as different energy loss moments [Ultramicroscopy 217 (2020), 113051]. In the HIM we demonstrate different contrasts, e.g., due to orientation of nanocrystals, channelling in single-crystalline membranes and material contrast for layered films [Beilstein J. Nanotechnol. 11 (2020), 1854].