Regensburg 2013 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 35: Poster Session I (Metal, semiconductor and oxide substrates: structure and adsorbates; Graphene)

O 35.82: Poster

Dienstag, 12. März 2013, 18:15–21:45, Poster B1

Downsizing graphene: routes towards epitaxial graphene nanoribbons (EGNR) on SiC — •Alexander Stöhr, Stiven Forti, and Ulrich Starke — Max Planck Institut für Festkörperforschung, Heisenbergstraße 1, 70569 Stuttgart, Germany

In recent years, great efforts have been spent in trying to realize a facile and scalable technique to produce graphene-based nanostructures for logic electronics. In this work we illustrate different experimental approaches to achieve quasi-1D structures based on epitaxial graphene (EG) on SiC. We present our first results about vicinal 4H-SiC surfaces, the 6H-SiC(1109) facet and anisotropic etching of graphene by means of metallic nanoparticles. Vicinal SiC surfaces offer a promising template for producing 1D graphene nanostructures on a wafer size due to the self-ordering of narrow terraces. Narrow trenches can be patterned into graphene by self-organized catalytic etching with metallic nanoparticles. By combination with H-intercalation of the buffer layer free-standing structured monolayer graphene can be obtained. We show nanoparticles deposition in a monodispersed distribution and the catalytic propagation in preferential directions. The bottom-up approach for definition of graphene nanostructures is of crucial importance since it avoids possible contaminations typical of the ex-situ lithographical approach. Nevertheless, patterned graphene relaxes into basal plane terraces and facets (e.g. (1109)) when annealed at elevated temperatures. To understand the graphene growth mechanism on those facets we investigated the (1109)-surface of 6H-SiC itself.