| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a NAND type EEPROM enabling high speed rewriting by enlarging a memory cell current of write-in-verify-read-out for normal read- out of data. SOLUTION: A NAND cell of this non-volatile semiconductor memory is constituted of memory cells MC0-MC31 and selection transistors SST, GST connected with each other in series. At the time of writing data, write-in voltage Vpgm is given to a selection word line of a selection block, pass voltage Vpass 2 is given to a non-selection word line, and electrons are injected to a floating gate in a selection memory cell. In verify-read-out operation after writing data, verify-read-out voltage is given to the selection word line and pass voltage Vpass 3 is given to the non-selection word line. The pass voltage Vpass 3 given to the non-selection word line at the time of verify-read-out is set to a higher value than the pass voltage Vpass given to the non-selection word line at the time of normal read-out of data.</p> |
