| 摘要 |
<p>PURPOSE:To provide a nonvolatile semiconductor memory in which data holding characteristics can be improved by suppressing a soft writing at the time of standby. CONSTITUTION:A nonvolatile semiconductor memory comprises memory cell 10 having a selecting transistor 11 connected at its source to a write line(WL) and at its gate to a write gate line(WG), a memory transistor 12 connected at its source to a drain of the transistor 11 and at its control gate to a control gate line(CG) and having a floating gate partly superposed with the source through a thin insulating film to be used for a tunnel effect between the control gate and a channel, and a selecting transistor 13 connected at its source to the drain of the transistor 12, at its gate to a read gate line(RG) and at its drain to a read line(RL). At the time of standby, the line WL and CG are set to 0V, a voltage of 5V is supplied to the line WG, and the control gate, the source of the transistor 12 are set to the same potential.</p> |
