| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor memory device which writes data so as to obtain high reading accuracy. <P>SOLUTION: The data writing method includes: a first current measurement step of measuring a value of currents passing between a drain terminal and a source terminal so as to correspond to each of charge accumulation sections in each of a drain side and a source side of memory cells as a first initial current value and a second initial current value before data are written; a comparison step of comparing the magnitude between the first initial current value and the second initial current value for each memory cell; a first charge injection step of injecting charges into the charge accumulation section in the source side corresponding to the first initial current value and bringing the first initial current value close to the second initial current value, when a comparison result of the comparison step that the first initial current value is larger than the second initial current value is obtained; and a second charge injection step of injecting charges into the charge accumulation section in the drain side corresponding to the second initial current value and bringing the second initial current value close to the first initial current value, when a comparison result of the comparison step that the second initial current value is larger than the first initial current value is obtained. <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
