| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent the data destruction of a non-selection block at the data erasing operation of one or multiple blocks, in a nonvolatile semiconductor memory device. <P>SOLUTION: As for a control procedure of the non-selection block at the data erasing operation of one or multiple blocks, a control gate line is used as a grounding potential first of all, and successively a transfer transistor of the non-selection block is turned OFF. After that, a high voltage is applied to a well region and after the data of a selection block are erased, the control gate line is charged to e.g. a voltage of 4V (Vcg) which is used in reading. After the control gate line is charged to Vcg, the high voltage applied to the well region is discharged. After the discharge of well region is finished, the control gate line is returned to the grounding potential, then the data erasing operation of block is finished. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
