Method for manufacturing trench MOSFET

A MOSFET is made by: forming a trench extending from an upper surface of a base layer to an internal portion of the base layer; forming a first insulating layer and a shield conductor occupying a lower portion of the trench; forming a gate dielectric layer and a gate conductor occupying an upper portion of the trench, where a top surface of the gate conductor is lower than the upper surface of the base layer; and before forming a body region, forming a blocking region on a region of the top surface of the gate conductor adjacent to sidewalls of the trench to prevent impurities from being implanted into the base layer from the sidewalls of the trench during subsequent ion implantation.