US Patent 7936004 Nonvolatile semiconductor memory device and manufacturing method thereof

A nonvolatile semiconductor memory device includes a plurality of the memory strings, in which a plurality of electrically programmable memory cells is connected in series. The memory strings comprise a pillar shaped semiconductor; a first insulation film formed around the pillar shaped semiconductor; a charge storage layer formed around the first insulation film; a second insulation film formed around the charge storage layer; and first or nth electrodes formed around the second insulation film (n is natural number more than 1). The first or nth electrodes of the memory string and the first to nth electrodes of at least two other memory strings which are adjacent to the memory string in two directions are shared as first to nth conductor layers spread in two dimensions.