| 摘要 |
A method of programming a NAND flash memory device having a multi-level cell is provided to suppress the degradation of reliability of the device due to cycling, by suppressing over-program of a memory cell due to the cycling. A NAND flash memory device has a multi-level cell having a first program level with smallest threshold voltage distribution(310), a second program level with middle threshold voltage distribution(320) and a third program level with largest threshold voltage distribution(330). The NAND flash memory device is programmed with the first program level, the second program level and the third program level using incremental step pulse program(ISPP) method using a start bias with different amplitude for the multi-level cell in an erased state.
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