Patent ID: 8466069

Claim:
A method for manufacturing a semiconductor device, the method comprising: forming a plurality of grooves extending in a first direction on a semiconductor substrate; forming an insulating layer on an inner face of the plurality of grooves and on a top face of the semiconductor substrate; depositing a first conductive layer on the insulating layer so as to fill in the plurality of grooves; depositing a second conductive layer on the first conductive layer; forming a hard mask in a region, including part of a region immediately above at least one of the plurality of grooves, on the second conductive layer; forming a columnar body including the hard mask and the second conductive layer by etching the second conductive layer using the hard mask as a mask; forming an electrode processing sidewall on two side faces, facing each other in a width direction of the at least one of the plurality of grooves, of the columnar body; removing an upper part of exposed portion in the first conductive layer and leaving a lower part of the exposed portion by performing etching using the columnar body and the electrode processing sidewall as a mask; removing the electrode processing sidewall; and removing the lower part of the exposed portion by performing etching using the columnar body as a mask.