Patent ID: 8124514

Claim:
A method for manufacturing a nonvolatile semiconductor storage device, the device including: a semiconductor layer; a gate electrode provided facing the semiconductor layer; a charge storage layer provided between the semiconductor layer and the gate electrode; a first insulating film provided between the semiconductor layer and the charge storage layer; and a second insulating film provided between the charge storage layer and the gate electrode, the method comprising: stacking to form a semiconductor layer film and an insulating layer film on a major surface of a substrate, the semiconductor layer film forming the semiconductor layer, the insulating layer film forming an insulating layer; processing the semiconductor layer film and the insulating layer film to alternately provide a first spacing and a second spacing larger than the first spacing between stacked units, by using a side wall as a mask pattern, the side wall being formed on a side face of a dummy pattern formed at a period four times a size of a half pitch F of the bit line of the device, the side wall aligning in a first direction parallel to the major surface, the stacked units including the semiconductor layer and the insulating layer; forming a film forming the first insulating film, a film forming the charge storage layer, and a film forming the second insulating film on a side face of the stacked unit on the second spacing side, and further forming a gate electrode film forming the gate electrode on the film forming the second insulating film and on a major surface of the stacked unit; and processing the gate electrode film into a band configuration aligning in a second direction parallel to the major surface and non-parallel to the first direction; wherein the charge storage layer film is separated for each side face of the stacked semiconductor layer on the second spacing side after the processing the gate electrode; wherein the separating the charge storage layer film includes selectively oxidizing the charge storage layer film by oxidizing via the stacked insulating layer.