| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor memory device in which erase time is shortened. <P>SOLUTION: When data of a memory block is erased, operation S3 in which an erase pulse is applied en bloc to the memory block and operation S6 in which the erase pulse is applied en bloc to a limited one part of region of the memory block are used jointly. Thereby, the number of erase pulses applied excessively to the memory cell becoming verify-pass can be reduced more than conventional one, consequently, the number of memory cells being an object of excessive erasure recovery writing S9 is reduced, and the total of a block blanking time can be shortened. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
