▎ 摘　　要

NOVELTY - The method involves providing a graphene nanoribbon composite structure, and the graphene nanoribbon composite structure includes a substrate (16) and multiple graphene nanoribbons (22). The substrate has multiple protrusions are arranged at intervals, multiple graphene nanoribbons are arranged on the substrate at intervals, and there is a graphene nanoribbon between adjacent protrusions. An interdigital electrode (210) is mounted on the surface of the graphene nanoribbon composite structure, and the interdigitated electrodes cover multiple protrusions are electrically connected with multiple graphene nanoribbons. USE - Method for preparing FET (claimed) such as junction gate JFET and metal-oxide semiconductor MOSFET. ADVANTAGE - The FET is prepared in large area with low cost and energy consumption. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a FET. DESCRIPTION OF DRAWING(S) - The drawing shows a flow chart of the method for preparing FET. Substrate (16) Graphene nanoribbons (22) Bump (164) Interdigital electrode (210)