Dr. Sang-hyun Oh Academic Affiliation: University of Minnesota Talk: August 7, 2018 Ultra-flat and Ultra-small: Towards Atomic-Resolution Engineering of Metallic
Dr. Sang-hyun Oh
Academic Affiliation: University of Minnesota
Talk: August 7, 2018
Ultra-flat and Ultra-small: Towards Atomic-Resolution Engineering of Metallic Nanostructures
This presentation will cover two unconventional nanofabrication techniques, namely, template stripping for making atomically smooth patterned metals [1-2] and atomic layer lithography for mass-producing sub-10 nm gaps [3-4]. These ‘enabling’ technologies have benefitted numerous applications in nanosciences, and we will show some examples.
Template stripping is widely used to create ultra-smooth metal films, plasmonic gratings, waveguides, high-Q resonators, and ultra-sharp pyramidal tips for near-field optical spectroscopy. In this unconventional process, instead of directly patterning metal films, which are difficult to plasma-etch, we engineer inverse patterns in a silicon template using mature IC processing techniques. After metal deposition and peeling, ultra-smooth patterns in the silicon template are replicated onto the deposited metal film. I will discuss applications of template-stripped metal films for near-field optical spectroscopy, plasmonics, and 2D materials.
Our group has demonstrated a new technique called atomic layer lithography [3-4], which leverages Angstrom-scale thickness resolution of atomic layer deposition to pattern equally small gaps and slits in metal films. Using this new method, we have demonstrated wafer-scale production of ultra-long (up to centimeters) and sub-10-nm wide gaps in various metals. The resulting devices have been used for a wide range of optical and electrical experiments, including extraordinary optical transmission through single-nanometer gaps, optical trapping of protein molecules, and surface-enhanced spectroscopies, to name a few. I will present broader potential applications of this technology.
 T. W. Johnson, Z. J. Lapin, R. Beams, N. C. Lindquist, S. G. Rodrigo, L. Novotny, S.-H. Oh. ACS Nano (2012) 6, 9168.
 H. Im, K. C. Bantz, N. C. Lindquist, C. L. Haynes, S.-H. Oh, Vertically oriented sub-10 nm plasmonic nanogap arrays, Nano Letters 10, 2231 (2010).
 X. Chen, H. Park, M. Pelton, X. Piao, N. C. Lindquist, H. Im, Y.J. Kim, J.S. Ahn, K.J. Ahn, N. Park, D.S. Kim, and S.-H. Oh. Nature Communications (2013) 4, 2361
7 (Tuesday) 2:00 pm - 9 (Thursday) 4:00 pm