▎ 摘　　要

NOVELTY - The method involves forming a graphene layer (18) within a trench (12) in a substrate (10) made of carbon-containing material and silicon. The device structure such as FET is provided on the graphene layer. USE - Method for forming graphene-based FET device (claimed). ADVANTAGE - The need for the etching process of the graphene layer is eliminated hence the formation process of the graphene-based FET device is simplified. The shape and dimension of the graphene layer can be accurately controlled by the process of the trench structure. The bonding of the graphene layer to the substrate is performed effectively and the reliability of the graphene-based FET device is improved. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for graphene-based device. DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view illustrating the method for forming graphene-based FET device. Substrate (10) Trench (12) Graphene layer (18) Gate dielectric (24) Metal contacts for gate, source and drain regions (26,28)