▎ 摘　　要

NOVELTY - A composite consists of a single crystal sapphire substrate, a metal film grown on the film-forming surface of substrate, and a graphene film grown on the metal film. The surface roughness of the surface on the opposite side of film-forming surface of substrate is less than 3 mu m. USE - Composite is used for electrode of transistor used in flexible device. ADVANTAGE - The composite has desired thermal conductivity, controlled reaction rate and deposition of carbon source in substrate surface, and lamination number of layers, reduced abnormal growth of graphene film, and suppressed generation of defects. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for manufacture of composite, which involves epitaxially growing the metal film on the sapphire substrate, and epitaxially growing the graphene film on the metal film.