| 摘要 |
A nonvolatile semiconductor memory device includes a plurality of memory strings, each of which has a plurality of electrically rewritable memory cells connected in series; and select transistors, one of which is connected to each of ends of each of the memory strings. Each of the memory strings is provided with a first semiconductor layer having a pair of columnar portions extending in a perpendicular direction with respect to a substrate, and a joining portion formed so as to join lower ends of the pair of columnar portions; a charge storage layer formed so as to surround a side surface of the columnar portions; and a first conductive layer formed so as to surround the side surface of the columnar portions and the charge storage layer, and configured to function as a control electrode of the memory cells. Each of the select transistors is provided with a second semiconductor layer extending upwardly from an upper surface of the columnar portions; and a second conductive layer formed so as to surround a side surface of the second semiconductor layer with a gap interposed, and configured to function as a control electrode of the select transistors.
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