Crystal orientation relation and macroscopic surface roughness in hetero-epitaxially grown graphene on Cu/mica

A clean, flat and orientation-identified graphene on a substrate is in high demand for graphene electronics. In this study, the hetero-epitaxial graphene growth on Cu(111)/mica(001) by chemical vapor deposition is investigated to check the applicability for the top-gate insulator research on graphene as well as the graphene channel research by transferring graphene on SiO2/Si substrates. After adjusting the graphene-growth condition, the surface roughness of the graphene/Cu/mica substrate and the average smooth area are ~0.34 nm and ~100 um2, respectively. The orientation of graphene in the graphene/Cu/mica substrate can be identified by the hexagonal void morphology of Cu. Moreover, we demonstrate the relatively high mobility of ~4500 cm2V-1s-1 in graphene transferred on the SiO2/Si substrate. These results suggest that the present graphene/Cu/mica substrate can be used for top-gate insulator research on graphene.