| 摘要 |
<p>PURPOSE:To prevent malfunction from being generated at a reading time by executing writing to a memory cell which is totally erased at an erasing mode time. CONSTITUTION:The writing is executed before the total erasing to all memory cells to be totally erased in a non-volatile semiconductor memory device, in which plural total erasing type memory cells to laminate floating gates 41, 42... and control gates 61, 62... on a semiconductor substrate are arranged. The threshold of the memory cell goes to be negative and the threshold after the total erasing is ordered at 2-3sigma. Accordingly, even when the cells, which has a writing mode not to execute an electronic discharge from the gates 41, 42..., are continued, the threshold is not changed and the malfunction at the reading time is prevented. Then, reliability is improved.</p> |
