METHOD FOR MANUFACTURING TRENCH GATE MOS STRUCTURES IN ICS AND ACCORDINGLY FABRICATED DEVICES

摘要

The method for manufacturing a trench gate MOS structure comprises a set of forming a trench having substantially vertical side walls into the surface of a semiconductor substrate, a step of forming a gate dielectric layer covering the bottom and sidewalls of the trench, a step of forming a gate electrode over the gate dielectric layer, a step of forming source and drain regions into the surface of the substrate said source and drain regions being separated from one another by the trench, and a step of forming an implant region (30) below or near the bottom of the trench and separating the source and drain region, said implant region having a doping level higher than that of the surrounding material.