▎ 摘　　要

High-quality monolayer graphene was grown on the Si face of SiC by thermal decomposition, and its electrical properties were investigated in top-gated devices. At 2 K, the carrier mobility of the graphene exceeded 10,000 cm(2) V(-1) s(-1) and the half-integer quantum Hall effect was observed. The quantum Hall states were even observed at various carrier densities when top-gate bias was applied. These findings suggest high-quality epitaxial graphene possesses the unique nature of monolayer graphene and is robust against device fabrication, which holds potential for graphene-based electronics applications. (C) 2010 The Japan Society of Applied Physics