| 摘要 |
<P>PROBLEM TO BE SOLVED: To relax stress to a memory cell and increase reliability of a memory. <P>SOLUTION: For data erase from an electrically erasable and programmable non-volatile memory cell, the following operations are performed: (1) an erase operation to apply an erase pulse voltage to a memory cell for data erase; (2) an erase verify operation to verify whether data erase is completed; and (3) a step-up operation to increase the erase pulse voltage by a certain step-up voltage if data erase is not completed. A control unit controls voltages so that at least a first erase pulse voltage initially generated in the erase operation has a longer rise time than that of a second erase pulse voltage generated subsequent to the first erase pulse voltage. <P>COPYRIGHT: (C)2011,JPO&INPIT |
