| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor memory device capable of executing stable operation. <P>SOLUTION: A memory string has a plurality of electrically rewritable memory transistors and a spare memory transistor connected in series. Word lines are connected to gates for the memory transistors. A spare word line is connected to a gate for the spare memory transistor. The memory string includes a first semiconductor layer, a charge storage layer, a plurality of first conductive layers and a second conductive layer. The first semiconductor layer includes a first semiconductor layer extending perpendicular to a substrate. The charge storage layer surrounds side faces of the first semiconductor layer. The plurality of first conductive layers surround the side faces of the first semiconductor layer via the charge storage layer, and function as the word lines. The second conductive layer surrounds the side faces of the first semiconductor layer via the charge storage layer, and functions as the spare word line. A control circuit can drive the spare word line in place of the word lines. <P>COPYRIGHT: (C)2012,JPO&INPIT |
