| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor storage device which can improve data retention characteristic, and to provide its data writing method. <P>SOLUTION: The nonvolatile semiconductor storage device comprises a memory cell array 11 and a control circuit 17. The control circuit checks writing data of unselected word lines adjacent to a selected word line when writing data (ST2), and controls data writing depending on the set voltages by setting a first writing verifying voltage Vpv1 when the threshold voltage of the unselected memory cells connected to the unselected word lines adjacent to the selected memory cell connected to the selected word line does not exceed a predetermined value out of the checked data, while setting a second writing verifying voltage Vpv2 greater than the first writing verifying voltage when the threshold voltage of the unselected memory cell is greater than the predetermined value out of the checked data (ST3). <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
