Berlin 2012 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 34: Poster Session I (Graphene; Plasmonics and nanooptics; Coherence and coherent control in nanophotonics and plasmonics)

O 34.12: Poster

Dienstag, 27. März 2012, 18:15–21:45, Poster E

Local anodic oxidation of graphene by scanning force microscopy — •Marcus Liebmann, Theresa Hecking, Alexander Nent, Lena Jung, Jonas van Bebber, Jens Kellner, Lisa Felker, Silke Hattendorf, Nils Freitag, and Markus Morgenstern — II. Phys. Inst. B, RWTH Aachen University and JARA-FIT, Germany

For structuring graphene flakes exfoliated on a substrate, local anodic oxidation (LAO) is an interesting tool which avoids the contamination of large parts of the flake during processing using conventional lithography. Being well-established for semiconductor nanostructures [1], this technique has also been applied to graphene more recently [2]. It makes use of the oxidation of the surface at the contact area between a sample and a scanning tip of an atomic force microscope (AFM) when a bias voltage is applied under ambient conditions.

Graphene flakes exfoliated on SiO₂ and contacted by Indium soldering are modified by LAO. We observe two main processes: oxidation and cutting, depending on parameters like voltage, load force, tip velocity, and humidity. Appropriate sets of parameters are investigated and first nanostructures are tested. Line widths of 40 nm could be achieved. Conductivity measurements indicate that cut lines are insulating and oxidized structures show sheet resistances of at least 300 GΩ. Graphene samples have also been prepared on BN and the morphology has been analyzed by AFM.

[1] R. Held et al., Appl. Phys. Lett. 71, 2689 (1997).

[2] A. J. M. Giesbers et al., Solid State Commun. 147, 366 (2008).