PROGRAM METHOD OF FLASH MEMORY CELL AND PROGRAM METHOD OF NAND FLASH MEMORY USING THE SAME, IN WHICH READ FAIL DUE TO OVER-PROGRAM IS IMPROVED

摘要

PURPOSE: A program method of a flash memory cell and a program method of a NAND flash memory using the same are provided to improve read fail due to over-program and to set a threshold voltage target during program of cells at free. CONSTITUTION: According to the program method of a flash memory cell, the flash memory cell is over-programmed(300). The over-programmed flash memory cell is recovered by controlling a gate bias of the flash memory cell. The second recovery is performed by controlling a bulk bias of the over-programmed flash memory cell after setting the gate bias as 0 voltage. The third recovery is performed by controlling the bulk bias of the over-programmed flash memory cell after floating the gate bias. And the fourth recovery is performed by controlling the bulk bias of the over-programmed flash memory cell using a self boosting operation(310 -320).