| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the reliability of data of a NAND-type nonvolatile semiconductor memory device.SOLUTION: A NAND-type nonvolatile semiconductor device comprises a memory cell array and a control circuit. The memory cell array comprises: memory strings in which a plurality of memory cells are connected in series; word lines which are connected to the plurality of memory cells; and bit lines which are connected to one ends of the memory strings. The control circuit performs: a program operation in which a write voltage is applied to the word lines in a write operation; a verification operation that is performed after the program operation; and a step-up operation in which a voltage, which is obtained by adding a step-up voltage to the write voltage, is set as the write voltage to a memory cell for which it is determined that writing is insufficient, out of the plurality of memory cells. The value of the step-up voltage increases each time the write voltage application operation is performed.</p> |
