Berlin 2008 – scientific programme
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O: Fachverband Oberflächenphysik
O 4: Nanostructures at Surfaces
O 4.3: Talk
Monday, February 25, 2008, 11:45–12:00, MA 042
Nanostructuring of the HOPG surface — •Artur Böttcher1, Markus Cudaj1, Daniel Löffler1, Sharali Malik2, Manfred Kappes1,2, Patrice Brenner3, and Dagmar Gerthsen3 — 1Institut für Physikalische Chemie, Universität Karlsruhe, Karlsruhe, Germany — 2Institut für Nanotechnologie, Forschungszentrum Karlsruhe, Germany — 3Laboratorium für Elektronenmikroskopie, Universität Karlsruhe, Germany
By combining the focused ion beam technique, 30keV-Ga+-FIB, with high-temperature oxidation well defined periodic structures were fabricated on HOPG surfaces [1]. The method exploits the high reactivity of the amorphous surface areas towards the oxidation-induced gasification of undercoordinated carbon sites, C→CO, CO2. Large surface areas covered by periodically arranged nanocavities, gratings and arrays of nm-sized squares have been fabricated routinely. The minimum width of the grooves written is limited by the interaction of the ion beam with the substrate and levels presently off at 80 nm. The mean depth of the grooves can be easily varied in the range up to 55 nm by applying different ionic doses. These parameters enable to fabricate large arrays of nanographene plates with desired size and shape. Two stages are clearly distinguishable in the kinetics of the etching process: within the early stage the amorphous carbon is removed and in the later stage the prism surfaces of the regular graphite are gradually gasified with lower efficiency. The integral removal probability depends on the surface temperature and ranges from 10 −11 to 10 −8 C/O2. [1] A. Böttcher et al. Nanotechnology, 17(2006)