Large Area Graphene Synthesis

Abstract: Herein we attempt to synthesize graphene by annealing epitaxial SiC thin films as a carbon source. Three principal methods of synthesis are attempted: 1) Straight annealing of SiC, 2) Annealing of Cu/SiC/Si, 3) Annealing of Ni/SiC/Si. In the vacuum annealing of SiC/Si structures, an attempt was made to sublimate silicon from the surface of SiC, where remaining carbon reforms into graphene. Subsequent characterization by Raman spectroscopy was inconclusive in identifying any graphitic formation. The second experiment utilizes evaporated nickel thin films, where upon annealing the carbon from the silicon carbide will migrate into the overlaying nickel film and with subsequent cooling, the dissolved carbon will segregate onto the nickel surface and form a graphitic layer. Annealed Ni/SiC/Si structures were characterized with Raman spectroscopy, and showed the presence of nanocrystaline graphite as described by Ferrari et al. [1]. In the final experiment using copper films, carbon from SiC will catalyse at the copper/SiC interface upon annealing. Raman characterization of these structures shows evidence of graphitic formation in only the thinnest copper films used in the experimental matrix.