NONVOLATILE SEMICONDUCTOR MEMORY DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor memory device in which a processing time of an erasure sequence is reduced.

SOLUTION: A nonvolatile semiconductor memory device includes an erasure circuit. In an erasure sequence, the erasure circuit performs an erasure operation for shifting a selected memory cell group including a plurality of memory cells selected by a plurality of first wiring lines to an erasure state; thereafter performs a soft program operation for resolving an excessive erasing state for the selected memory cell group; and thereafter performs a first program verify operation for confirming whether one of a first partial selected memory cell group as a part of the selected memory cell group and a second partial selected memory cell group as another part thereof includes the predetermined number or more of the memory cells having a threshold value of a predetermined first threshold value or more.

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