Fabrication of Thin Graphene Layers on a Stacked 6H-SiC Surface in a Graphite Enclosure

Thin and homogeneous epitaxial graphene (EG) layers on a 6H-SiC (0001) substrate are fabricated and they cover the whole substrate (10×10 mm²). The sample surface is capped by another 6H-SiC (0001) wafer in a graphite enclosure to form a relatively high Si partial pressure between them, which significantly reduces the extremely high growth rate of EG. The structure and morphology of the EG layers are investigated by Raman spectroscopy, atomic force microscopy and field-emission scanning electronic microscopy. The results are compared with an uncapped sample surface, and reveal the obvious existence of ridges on the surface of the EG, and show that capping is indeed beneficial to obtain homogeneous graphene.