title: Photoplastic near-field optical probe with sub-100 nm aperture made by replication from a nanomould.
abstract: Polymers have the ability to conform to surface contours down to a few nanometres. We studied the filling of transparent epoxy-type EPON SU-8 into nanoscale apertures made in a thin metal film as a new method for polymer/metal near-field optical structures. Mould replica processes combining silicon micromachining with the photo-curable SU-8 offer great potential for low-cost nanostructure fabrication. In addition to offering a route for mass production, the transparent pyramidal probes are expected to improve light transmission thanks to a wider geometry near the aperture. By combining silicon MEMS, mould geometry tuning by oxidation, anti-adhesion coating by self-assembled monolayer and mechanical release steps, we propose an advanced method for near-field optical probe fabrication. The major improvement is the possibility to fabricate nanoscale apertures directly on wafer scale during the microfabrication process and not on free-standing tips. Optical measurements were performed with the fabricated probes. The full width half maximum after a Gaussian fit of the intensity profile indicates a lateral optical resolution of approximately 60 nm.
authors.affiliation: Microsystems Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland MESA Research Institute, University of Twente, The Netherlands. gyuman.kim@epfl.ch
authors.forename: G M
authors.initials: GM
authors.lastname: Kim
authors.forename: B J
authors.initials: BJ
authors.lastname: Kim
authors.forename: E S
authors.initials: ES
authors.lastname: Ten Have
authors.forename: F
authors.initials: F
authors.lastname: Segerink
authors.forename: N F
authors.initials: NF
authors.lastname: Van Hulst
authors.forename: J
authors.initials: J
authors.lastname: Brugger
mesh_terms: D000535:Aluminum / Q000737:chemistry; D004867:Equipment Design; D020527:Microscopy, Scanning Probe / Q000295:instrumentation* / Q000379:methods; D036103:Nanotechnology; D011108:Polymers / Q000032:analysis / Q000737:chemistry*
chemical_list: D011108:Polymers; D000535:Aluminum