▎ 摘　　要

NOVELTY - The method involves heating (S101) the silicon carbide substrate to a preset temperature. The preset temperature is used to sublime silicon atoms on the silicon carbide substrate. The carbon atoms are reconstituted on the silicon carbide substrate after sublimation of the silicon atoms. A layer of graphene film is formed on the surface of the silicon carbide substrate. A source, a drain, and a gate are deposited (S102) on the graphene film. The depositing step of source, drain, and gate on graphene film includes hydrogenating the graphene film between the source and the drain to obtain a hydrogenated graphene film. A gate dielectric layer is deposited on the hydrogenated graphene film. The gate dielectric layer is made of aluminum oxide (Al2O3) or hafnium oxide (HfO2). The source, the gate and the drain are electrodes of a titanium-gold mixed material. USE - Method of preparing FET. ADVANTAGE - The FET can obtain high quality graphene, improve carrier mobility, reduce noise, and realize terahertz band transmission. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a FET. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic flow chart illustrating the method for preparing a FET. (Drawing includes non-English language text) Step for heating the silicon carbide substrate to a preset temperature (S101) Step for depositing source, drain, and gate on the graphene film (S102)