| 摘要 |
A program method of a flash memory device is provided to change a program voltage properly with a program voltage corresponding to upper distribution after completing verification of lower distribution, by setting the program voltage according to the distribution of a cell voltage. According to a program method of a flash memory device including multi level cells having each level, program is performed from a first start voltage set for cells of a first level. Program pass is judged for the cells of the first level by using a first verify voltage, and program is performed again by increasing a voltage sequentially if the program for the cells of the first level does not pass. In case of program pass for the first verify voltage, program is performed from a present program voltage or a second start voltage by comparing the present program voltage with the second start voltage set for cells of a second level. Program pass for the cells of the second level is judged by using a second verify voltage, and program is performed again by increasing the voltage sequentially if the program for the cells of the second level does not pass.
|
