Dresden 2017 – scientific programme

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MI: Fachverband Mikrosonden

MI 7: Poster: Microanalysis and Microscopy

MI 7.2: Poster

Wednesday, March 22, 2017, 18:00–20:00, P4

Ultra-narrow Germanium-slits and waveguides for laboratory and synchrotron x-ray applications — •Ferdinand Döring, Sarah Hoffmann-Urlaub, Mike Kanbach, and Tim Salditt — Institute for X-Ray Physics Friedrich-Hund-Platz 1 37077 Göttingen Germany

Modern nano-beam x-ray diffraction and imaging applications are based on accuratly manufactured elements. Recently we developed x-ray waveguides to facilitate coherence beams with flat wavefrontsconfined down to below 20nm. To open a new oppotiunity for beamshaping, we adapted the known processes of waveguide fabrication to slit production. For a larger angular acceptance, the optical thickness has to be reduced while the absorption (in the cladding) needs to stay sufficiently high. Therefore, we replaced silicon by germanium as cladding material. We use a lithographic manufacturing processes at UV 400nm in combination with reactive ion etching and germanium wafer bonding of 500um thick 20mm x 20mm sampels. Along the vertical direction, the slit size is varied from 100nm up to 1000nm, while the horizontal size is in the rage between 1um and 1000um. Germanium slits showed a prominent modification of the challes during cross-section bonding. The growth of an interlayer inside the channels decreases the wall roughness resulting in round boundaries. That is why we applied the improved germaniumprocess to waveguide fabrication with the result of approximately round waveguid channels exhibiting a diameter of 100 nm and a multimodal exit field of hight transmission. The fabrication is guided by finite differences simulation.