▎ 摘　　要

NOVELTY - The FET has a transistor unit whose rear gate metal electrode is arranged on a substrate, where the substrate is made of hexagonal-boron nitride (h-BN) material i.e. two-dimensional plane material. A rear gate dielectric layer is formed on the rear gate metal electrode. A graphene single layer is matched with the rear gate dielectric layer and a top gate metal electrode. The transistor unit is formed with multiple layers in parallel manner. A source electrode and a drain electrode of the transistor unit are connected together in parallel manner. USE - Multi-layer graphene double-grid FET for use in a high frequency large power device. ADVANTAGE - The FET has wide range of applications, and utilizes hexagonal-boron nitride as top gate and bottom gate media- so as to improve graphene channel carrier mobility and limit graphene FET drain-source current. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a multi-layer graphene double-grid FET preparing method. DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of a multi-layer graphene double-grid FET. '(Drawing includes non-English language text)'