title: Silica-gold bilayer-based transfer of focused ion beam-fabricated nanostructures.
abstract: The demand for using nanostructures fabricated by focused ion beam (FIB) on delicate substrates or as building blocks for complex devices motivates the development of protocols that allow FIB-fabricated nanostructures to be transferred from the original substrate to the desired target. However, transfer of FIB-fabricated nanostructures is severely hindered by FIB-induced welding of structure and substrate. Here we present two (ex and in situ) transfer methods for FIB-fabricated nanostructures based on a silica-gold bilayer evaporated onto a bulk substrate. Utilizing the poor adhesion between silica and gold, the nanostructures can be mechanically separated from the bulk substrate. For the ex situ transfer, a spin-coated poly(methyl methacrylate) film is used to carry the nanostructures so that the bilayer can be etched away after being peeled off. For the in situ transfer, using a micro-manipulator inside the FIB machine, a cut-out piece of silica on which a nanostructure has been fabricated is peeled off from the bulk substrate and thus carries the nanostructure to a target substrate. We demonstrate the performance of both methods by transferring plasmonic nano-antennas fabricated from single-crystalline gold flakes by FIB milling to a silicon wafer and to a scanning probe tip.
authors.affiliation: Nano-Optics and Biophotonics Group, Experimentelle Physik 5, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany. hecht@physik.uni-wuerzburg.de.
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Wu
authors.forename: Peter
authors.initials: P
authors.lastname: Geisler
authors.forename: Enno
authors.initials: E
authors.lastname: Krauss
authors.forename: René
authors.initials: R
authors.lastname: Kullock
authors.forename: Bert
authors.initials: B
authors.lastname: Hecht