| AVS 59th Annual International Symposium and Exhibition | |
| Advanced Surface Engineering | Monday Sessions |
| Session SE+NS-MoA |
| Session: | Nanostructured Thin Films and Coatings II: Multifunctional Properties |
| Presenter: | J.A. Grant-Jacob, Optoelectronics Research Centre |
| Authors: | J.A. Grant-Jacob, Optoelectronics Research Centre W.S. Brocklesby, Optoelectronics Research Centre T. Melvin, Optoelectronics Research Centre |
| Correspondent: | Click to Email |
Thin films of micro and nanostructured metals are important for the construction of plasmonic devices and microelectromechanical systems (MEMs). The fabrication of individual metallic, pyramidal shells as well as ultra-smooth metal films with grooves, bumps, pyramids and holes has previously been demonstrated1,2, as has direct raster milling with 5 nm machining precision in 100 nm thick gold films3. Routine fabrication of micro and nanostructured thin films is desirable. In this work, the fabrication of arrays of nanoscale pyramidal structures in free-standing gold films is demonstrated, and single nanopores are milled into the nanostructures for DNA translocation.
Silicon Klarite® pyramidal micro-structured substrates are an effective tool for surface enhanced Raman scattering (SERS) experiments, owing to the strong field enhancement within the pyramids. Here, the substrates are used as moulds for creating pyramidal structured gold as free-standing thin films. The silicon substrates contain an array of pyramids etched into a 4 mm x 4 mm square region on the substrate’s surface. These pyramids are 1.5 µm x 1.5 µm square and 1 µm deep on a pitch of 2 µm. An Edwards E306A Thermal Evaporator is used to coat silicon samples in a 50 nm layer of Teflon® and then a 100 nm layer of gold. Epoxy is then deposited on top of the gold layer using a pipette. Once the epoxy has cured, the epoxy together with the gold is mechanically lifted from the Teflon® coated substrate. The gold-coated epoxy is then placed over a micron-sized aperture and the epoxy dissolved away using acetone. Initial imaging is performed using a Carl Zeiss SMT, Inc., Evo® scanning electron microscope (SEM), while the subsequent imaging and milling of 50 nm holes through the free-standing gold is carried out using an Carl Zeiss SMT, Inc., Orion® Plus helium ion microscope (HIM). These films are suspended over micron-sized apertures for integration into platforms already proven for DNA translocation, and to optically interrogate the structures using Raman based techniques.
1 Q. Xu, I. Tonks, M.J. Fuerstman, J.C. Love, and G.M. Whitesides, Nano Letters 4, 2509-2511 (2004).
2 P. Nagpal, N.C. Lindquist, S.-H. Oh, and D.J. Norris, Science (New York, N.Y.) 325, 594-7 (2009).
3 L. Scipioni, D.C. Ferranti, V.S. Smentkowski, and R. a. Potyrailo, Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures 28, C6P18 (2010).