A method for manufacturing a semiconductor device comprises the steps of forming a gate trench in a semiconductor substrate, forming a gate insulation film in an inner wall of the gate trench, filling a gate electrode material into at least an inside of the gate trench, forming a gate electrode by patterning the gate electrode material, and selectively forming a punch-through stopper region prior to patterning the gate electrode material, using a mask in a prescribed position of the semiconductor substrate that is adjacent to the gate trench. The step for forming the punch-through stopper region may be performed subsequent to the step for filling the gate electrode material into the gate trench, or may be performed prior to the step for forming the gate trench. |