| CPC G11C 16/16 (2013.01) [G11C 16/0466 (2013.01); G11C 16/0483 (2013.01); G11C 16/26 (2013.01); G11C 16/3445 (2013.01); G11C 16/06 (2013.01); G11C 16/08 (2013.01); G11C 16/10 (2013.01)] | 20 Claims |

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1. A semiconductor memory device comprising:
a memory block including a first memory string and a second memory string, the first memory string including a first transistor, a second transistor and a first memory cell, the second memory string including a third transistor, a fourth transistor and a second memory cell;
a bit line connected to a node of the first transistor and a node of the third transistor;
a first select gate line connected to a gate of the first transistor;
a second select gate line connected to a gate of the third transistor;
a word line connected to a gate of the first memory cell and a gate of the second memory cell; and
a controller coupled to the memory block, the controller configured to, during a time period for erase verify operations on the first memory string and the second memory string:
apply a selection voltage to the first select gate line or the second select gate line to discharge the first select gate line or the second select gate line to which the selection voltage is applied, and
apply an erase verify voltage to the word line and discharge the word line,
wherein, during the time period for the erase verify operations, a total number of times the first select gate line and the second select gate line are discharged is larger than a number of times the word line is discharged.
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