| 摘要 |
A method for programming a NAND flash memory device is provided to increase program speed by minimizing threshold voltage difference according to a page. According to a method for programming a flash memory device comprising a memory cell block having 2N memory cells, a memory cell to be programmed is selected among the plurality of memory cells. The selected memory cell is programmed by supplying a program voltage to a gate of the selected memory cell. The memory cell is verified to be in a program state. If a cell is not programmed, it is judged that which of a first group, a second group and a third group the memory cell belongs to. The first group comprises even-numbered memory cells except (2N-2)th memory cell, and the second group comprises odd-numbered memory cells except (N-1)th memory cell, and the third group comprises the (2N-2)th memory cell and the (N-1)th memory cell. If the cell belongs to the first group, a program voltage increased as much as a first step voltage(Vs1) is applied to program the memory cell. If the cell belongs to the second group, a program voltage increased as much as a second step voltage(Vs2) is applied to program the memory cell. If the cell belongs to the third group, a program voltage increased as much as a third step voltage(Vs3) is applied to program the memory cell.
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