A method for manufacturing a semiconductor device includes forming a gate insulation film and a polysilicon layer on a substrate, forming a polysilicon pattern by etching the polysilicon layer, forming an opening in the polysilicon pattern that exposes a part of the polysilicon pattern by forming a mask pattern on the polysilicon pattern, forming a gate electrode by etching the part of the polysilicon pattern exposed through the opening, forming a P-type body region by ion implanting a P-type dopant onto the substrate using the gate electrode as a mask, forming an N-type LDD region on the P-type body region by ion implanting an N-type dopant onto the substrate using the gate electrode as a mask, forming a spacer on a side surface of the gate electrode, and forming an N-type source region on a side surface of the spacer.