Patent ID: 8728919

Claim:
A method of manufacturing a non-volatile semiconductor storage device having a plurality of memory strings each having a plurality of electrically rewritable memory cells connected in series, the method comprising: forming a plurality of first conductive layers above a substrate, with first interlayer insulation layers sandwiched between the plurality of first conductive layers; forming first holes to penetrate the plurality of first conductive layers and the first interlayer insulation layers; sequentially forming a second conductive layer and a first semiconductor layer on a side surface of each of the first holes, the second conductive layer surrounded by an insulation layer; forming first trenches to penetrate the plurality of first conductive layers and the first interlayer insulation layers, the first trenches extending in a first direction parallel to the substrate; removing the first interlayer insulation layers via the first trenches to form air gaps between the first conductive layers aligned in a vertical direction with respect to the substrate; and oxidizing parts of the second conductive layers via the first trenches and the air gaps.