Dresden 2017 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

MM: Fachverband Metall- und Materialphysik

MM 22: Poster session I

MM 22.24: Poster

Monday, March 20, 2017, 19:00–20:00, P4

Planarization and pattern transfer at ultra-smooth aluminium surfaces — •Jens Bauer, Frank Frost, and Thomas Arnold — Leibniz-Institut für Oberflächenmodifizierung, Permoserstraße 15, D-04318 Leipzig, Germany

Metal mirrors are of increasing interest for the technological progress in EUV/XUV lithography, x-ray and synchrotron optics. Recently, we have presented a direct surface figuring technology, which is based on reactive ion beam etch (RIBE) processing. The use of sub-aperture ion beams allows the deterministic machining of optical Al surfaces while preserving the surface roughness almost in its initial state. Now we apply this promising technique for an advanced customization of the Al surface topography. Two cases are distinguished: 1) Surface planarization experiments are performed applying a sacrificial resist layer. Typically, several hundred nanometres of resist allow for a geometrical levelling of disturbances within the surface micro-roughness and waviness. This smooth resist topography is then transferred into the Al surface. RIBE process optimization is performed by variation of the gas composition and ion beam machining geometry to achieve a resist/Al selectivity in the order of unity. 2) Al surfaces are structured by topography transfer of a patterned resist layer via RIBE. The proportional pattern transfer is controlled by the resist/Al selectivity. The engraving of regular ultra-shallow grid patterns into aluminium is performed by a damped proportional transfer. The processes are evaluated by AFM and WLI topography measurements. A PSD analysis allows for the quantitative assessment of topography features.