| 摘要 |
PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor storage device whose data erase operation is increased in speed.SOLUTION: A nonvolatile semiconductor storage device according to an embodiment includes a memory string obtained by connecting a plurality of memory transistors, which are electrically rewritable, in series. The memory string includes a first semiconductor layer including a columnar part, which extends in a vertical direction with respect to a substrate, and functioning as a body of the memory transistors, a tunnel insulation film formed to surround a side surface of the columnar part, a charge accumulation film formed to surround the tunnel insulation film and constructed to be able to accumulate electric charge, a block insulation film formed to surround the charge accumulation film, and a plurality of first conductive layers formed to surround the block insulation film and arranged with predetermined intervals along the vertical direction. The charge accumulation film includes a first charge accumulation film having conductivity and formed on a tunnel insulation film side, and a second charge accumulation film having an insulation property and formed between the first charge accumulation film and the block insulation film. |
