▎ 摘　　要

We have investigated transport characteristics of epitaxial graphene grown on semi-insulating silicon-face 4H-silicon carbide (SiC) substrate by thermal decomposition method in relatively high N-2 pressure atmosphere. We have succeeded in forming 1-2 layers of graphene on SiC in controlled manner. The surface morphology of formed graphene was analyzed by atomic force microscopy (AFM), low-energy electron diffraction (LEED) and low-energy electron microscope (LEEM). We have confirmed single-layer graphene growth in average by this method. Top-gated, single-layer graphene field-effect transistors (FETs) were fabricated on epitaxial graphene grown on 4H-SiC. Increased on/off ratio of nearly 100 at low temperature and extremely small minimum conductance (0.018-0.3 in 4 e(2)/h) in gated Hall-bar samples suggest possible band-gap opening of single-layer epitaxial graphene grown on Si-face SiC. (C) 2010 Elsevier B.V. All rights reserved.