Stimulated Emission Depletion Lithography with Mercapto-Functional Polymers
B. Buchegger, J. Kreutzer, B. Plochberger, R. Wollhofen, J. Jacak, G. Schütz, U. Schubert, T. Klar - Stimulated Emission Depletion Lithography with Mercapto-Functional Polymers - ACS Nano, Vol. 1021, No. 1, 2016
Surface reactive nanostructures were fabricated using stimulated emission depletion (STED) lithography. A functionalization of the nanostructures was realized by co-polymerization of a bifunctional metal oxo cluster in the presence of a triacrylate monomer. Methacrylate ligands of the clusters' surface crosslink with the polymer during the lithographic process, while the mercapto ligands remain reactive on the surface of the nanostructure after polymerization. For STED lithography it is important that the resin is fully depletable by stimulated emission. We show that a full depletion is achieved with a cluster loading exceeding 4 % wt. A λ/11 lateral feature size was achieved by applying a donut shaped STED focus.