▎ 摘　　要

NOVELTY - A circuit apparatus comprises a graphene film which consists of several layers, metal electrode (203) directly joined to the graphene film, and a metal electrode (204) directly joined to the graphene film. The graphene film has conductive-type doped regions formed between the metal electrode (203) and metal electrode (204). Where, 90% or more of region of the graphene film in the region joined to the metal electrode (203) and 90% or more of region of the graphene film in the region joined to the metal electrode (204) is doped by conductive-type dopant. USE - Circuit apparatus is used for electronic integrated circuit device and electronic/optical integrated circuit apparatus (all claimed). ADVANTAGE - The contact resistance between the electrical joining of the graphene film and metal electrode in circuit apparatus is reduced. DESCRIPTION OF DRAWING(S) - The drawing shows the structure of circuit apparatus. Graphene channels (201,207) Gate insulating layer (202) Metal electrodes (203,204) Gate electrode (205) Source electrode (206)