Patent ID: 8199573

Claim:
A nonvolatile semiconductor memory device, comprising: a bit line; a source line; a memory string having a plurality of electrically data-rewritable memory transistors connected in series; a first select transistor provided between one end of the memory string and the bit line; a second select transistor provided between another end of the memory string and the source line; and a control circuit configured to control a read operation, a plurality of the memory strings being connected to one bit line via a plurality of the first select transistors, the memory string comprising: a first semiconductor layer including a columnar portion extending in a stacking direction on a substrate and functioning as a body of the memory transistors; a first charge storage layer surrounding the columnar portion and holding data of the memory transistors by storing a charge; and a plurality of first conductive layers stacked on the substrate so as to surround the first charge storage layer and functioning as gates of the memory transistors, the first select transistor comprising: a second semiconductor layer in contact with an end of the columnar portion and extending in the stacking direction, and functioning as a body of the first select transistor; a first gate insulating layer surrounding the second semiconductor layer; and a second conductive layer surrounding the first gate insulating layer and functioning as a gate of the first select transistor, and the second select transistor comprising: a third semiconductor layer in contact with an end of the columnar portion and extending in the stacking direction, and functioning as a body of the second select transistor; a second gate insulating layer surrounding the third semiconductor layer; and a third conductive layer surrounding the second gate insulating layer and functioning as a gate of the second select transistor, during reading of data from a selected one of the memory strings, the control circuit being configured to render conductive the first select transistor connected to an unselected one of the memory strings and render non-conductive the second select transistor connected to unselected one of the memory strings.