Regensburg 2013 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 15: Poster Session

MM 15.84: Poster

Montag, 11. März 2013, 18:00–20:00, Poster E

Freely suspended membranes from epitaxial graphene on silicon carbide — •Christian Dolle¹, Benjamin Butz¹, Daniel Waldmann², Heiko Weber², and Erdmann Spiecker¹ — ¹Center for Nanoanalysis and Electron Microscopy (CENEM), Universität Erlangen-Nürnberg — ²Lehrstuhl für Angewandte Physik, Universität Erlangen-Nürnberg

We present a route to produce freely suspended graphene membranes by thermal decomposition of SiC(0001) at 1760^∘ C under reduced inert gas atmosphere yielding a mean of 1.2-1.5 layers of high crystalline-quality graphene. Laser-assisted electro-chemical removal of the SiC substrate in KOH at lithographically predefined areas allows us to tailor the number and shapes of the membranes with sizes up to at least 500 µm². We carried out a thorough characterization of the freely-suspended membranes employing Raman spectroscopy, SEM, low-kV-STEM and plan-view TEM. The powerful tool of abberation-corrected TEM can resolve the spatial distribution of one up to four graphene layers on the membranes and contrast variation in dark-field imaging allows a straightforward and facile assignment of the number of layers. One of the great benefits of the preparation procedure is the high cleanliness of the samples, allowing high resolution imaging even without the need of precedent heat treatment although the membranes withstand in-situ thermal exposure up to 1000^∘ C in vacuo without mentionable damage.