Abstract: A MOSFET comprising an epitaxial layer of a semiconductor substrate of a first conductivity type, the MOSFET comprises a polysilicon gate, a source region of the first conductivity type and a body region of a second conductivity type, the polysilicon gate comprises a first layer of polysilicon and a second layer of polysilicon sandwiching a layer of polysilicon etch stop substances.

Abstract: A method of forming a power MOSFET having a substrate of a first conductivity type and a body region of a second conductivity type. The method includes the steps of forming a gate region of a predetermined pattern and with a plurality of gate elements partially covering the substrate. The gate element has a stepped cross-sectional profile with a thicker portion and a thinner portion. The thicker portion is adapted to substantially prevent passage of impurities therethrough into the substrate during the impurities implantation step. The thinner portion is adapted to allow partial passage of impurities therethrough during the impurities implantation step. Impurities are implanted into the substrate from the gate region side of the substrate to form a body region of the second conductivity type.