SELF-ALIGNED GATE STRUCTURE FOR FIELD EFFECT TRANSISTOR

摘要

A field effect transistor has a substrate with an epitaxial layer, base regions extending from a top of the epitaxial layer into the epitaxial layer, an insulation region having side walls and extending between two base regions on top of the substrate; and a polysilicon gate structure covering the insulation region including the side walls, wherein effective gates are formed by a portion of the polysilicon covering side walls above the base region.