Patent ID: 7682974

Claim:
A method for manufacturing a semiconductor device comprising the steps of: forming an etching layer formed of silicon on a semiconductor substrate; forming a mask layer with a pattern on the etching layer, the mask layer including an intermediate layer formed of a silicon oxide film and a top layer formed of silicon, wherein the step of forming the mask layer includes the steps of: layering the intermediate layer and the top layer on the etching layer; patterning the intermediate layer and the top layer; forming a cover layer formed of a silicon oxide film on the patterned intermediate layer and the top layer; and forming side wall layers on side surfaces of the patterned intermediate layer and the patterned top layer by etching an entire surface of the cover layer to expose the top layer; and etching the etching layer using the mask layer as a mask, and eliminating the top layer, the etching layer etched to form a plurality of word lines.