| 摘要 |
<p>In a non-volatile semiconductor memory device including a floating gate type memory cell, after the drain or source is charged, it is placed in an electrically floating state and a signal with alternately changing positive and negative potentials is applied to the control gate of the memory cell so as to reduce the charges stored in the floating gate, thereby converging the threshold voltage of the memory cell into a predetermined voltage. Thus, a write/erase operation in the memory device can be carried out surely in a short time.</p> |
