▎ 摘　　要

NOVELTY - The varactor has electrodes (206, 210) embedded in a surface of a substrate (202). A capacitor dielectric layer (208) is placed over the first electrode. A graphene layer is placed over the first electrode in contact with the dielectric layer to contribute a quantum capacitance component to the dielectric layer. An upper electrode is formed with the graphene layer. The dielectric layer includes a high dielectric constant. The first electrode and the upper electrode are extended to cover lateral extents of the graphene layer, where the graphene layer includes a single layer of graphene. USE - Plate varactor for use in silicon technologies. ADVANTAGE - The electrodes completely cover graphene area, thus reducing contact resistance and improving varactor's quality factor. The varactor employs quantum capacitance effects of graphene material to adjust capacitance of the varactor. The electrode is formed over edges or periphery of the graphene layer with sufficient coverage area to provide adequate resistance, easy process flow, higher tunability and better performance than conventional counterparts. DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of an upper electrode formed on a dielectric layer and over a graphene layer. Substrate (202) Graphene material (204) Electrodes (206, 210) Capacitor dielectric layer (208) Relief zones (216)