| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a nonvolatile semiconductor memory device which surely guarantees erasure threshold level. <P>SOLUTION: A nonvolatile semiconductor memory device includes a NAND cell unit, wherein a plurality of electrically rewritable and non-volatile memory cells are connected in series, one end thereof is coupled to a bit line via a first select gate transistor and the other end is coupled to a source line via a second select gate transistor. The memory device performs separate verify read for two memory cells adjacent to first and second selection gate transistors as an erase-verify operations for verifying the erasure state of the memory cell in the NAND cell unit. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
