A new direct growth of high quality graphene on Si-face of 6H-SiC by inner and external carbon sources catalyzed by Nickel

Graphene has been expected for use in various disciplines due to its super properties such as high carrier mobility, chemical stability, optical transparency and low density etc. Recently, chemical vapor deposition (CVD) and epitaxial growth (EG) on SiC have been demonstrated the most successful methods for growing high quality graphene film. However, the CVD method relies on metallic substrates and the grown graphene has to be stripped off and transferred to the insulating substrate for further applications. Multilayer graphene can be directly grown on SiC wafer using epitaxial growth method, but the buffer layer between SiC substrate and graphene would reduce the carrier mobility of graphene and impede the application of the graphene. In this work, we combined the advantages of the above two methods and proposed a novel and feasible method for growing graphene on Si-face of 6H-SiC by diffusion and precipitation of the inner and external carbon sources. A layer of nickel was deposited on the surface of 6H-SiC, which can catalyze the synthesis of graphene. SEM and Raman spectra results confirmed the formation of high-quality graphene and the grown graphene was single layer. The graphene was obtained within just 10min, more than one order of magnitude faster than that of the graphene grown on 6H-SiC substrates by traditional EG method. More interesting, the annealing temperature of this method was 200∼300 °C, lower than that of the traditional EG method. The directly grown graphene could be compatible with the semiconductor technique, benefit for the applications of graphene-based microelectronic devices.