| 摘要 |
<p>PROBLEM TO BE SOLVED: To prolong the life of a non-volatile semiconductor memory by extending the limit to writw-and-erase cycle in the non-volatile semiconductor memory. SOLUTION: In the non-volatile semiconductor memory, which has a floating gate 3 and a control gate 8 to erase the information loaded in the floating gate 3 by releasing electric charge (electron) to the control gate 8 from the floating control gate 3 utilizing a tunnel effect in the erasing of information, an erase gate 17 exclusively used for erasing is provided in addition to the control gate 8 and a drive circuit 101 is arranged to switch the control gate 8 and the erase gate 17 sequentially at each erasing operation. The pass of the electric charge (electron) during the erasing operation is dispersed to delay the worsening of an electric charge releasing efficiency. Thus, the limit to the erasing cycle is extended thereby achieving a longer life of the non-volatile semiconductor memory.</p> |
