Berlin 2012 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 71: Poster Session: Graphene / Topological Insulators / Interfaces and Surfaces
HL 71.10: Poster
Mittwoch, 28. März 2012, 16:00–19:00, Poster D
Crystallographically Anisotropic Etching of Graphene — •Florian Oberhuber, Paula Giudici, Stefanie Heydrich, Tobias Korn, Christian Schüller, Dieter Weiss, and Jonathan Eroms — Institut für Experimentelle und Angewandte Physik, Universtität Regensburg, 93040 Regensburg, Germany
We report the crystallographically anisotropic etching of exfoliated graphene on SiO2 substrates by a carbothermal reaction. The etching mechanism was suggested to take place between graphene and oxygen from the SiO2 substrate and leading to graphene with zigzag edges [1]. Before exposing samples to this carbothermal reaction, they were patterned with circular antidots by electron beam lithography and reactive ion etching with oxygen plasma. In the following carbothermal etching samples were exposed to temperatures around 800∘C in a flow of argon gas (purity 6.0) and the predefined holes evolved into larger hexagonal antidots. Samples were characterized by Raman spectroscopy focussing on G (∼1580cm−1), D (∼1350cm−1) and D’ (∼1620cm−1) peaks. On the other hand we investigated electron transport on a set of samples patterned with square lattices of hexagonal holes. By analizing the weak localization peak we obtain the phase coherence length as well as lengths for intra- and intervalley scattering. The results will be compared to graphene patterned with circular holes investigated previously [2].
[1] P. Nemes-Incze et al., Nano Res. 3 (2010)
[2] J. Eroms et al., New J. Phys. 11 (2009)