According to one embodiment, a method includes forming a gate insulating layer structure covering first and second stacked layer structures, forming a first conductive layer on the gate insulating layer structure, forming a sacrifice layer on the first conductive layer, patterning the first conductive layer and the sacrifice layer with a line & space pattern, filling an insulating layer in spaces of the line & space pattern, the insulating layer having an etching characteristic different from the sacrifice layer, forming trenches in lines of the line & space pattern by removing the sacrifice layer selectively, the trenches exposing the first conductive layer between the first and second stacked layer structures, and forming a second conductive layer on the first conductive layer in the trenches.