Design of unique NAND flash memory cells with low program disturbance utilizing novel booster line

Abstract

Unique NAND flash memory cells with a booster line structure were designed to increase the channel voltage of a program-inhibited cell during program cycles. When a program voltage was applied to the selected word line, booster-line voltage coupled with control gate potential induced a high voltage in a program-inhibited channel. Because the turning on of the unselected cells was initiated by the booster line during programming, an unselected word line was maintained in the floating state without applying a pass voltage. Program disturbance in the NAND flash memory cell was decreased using a booster-line boosting scheme, and the cell's pass disturbance was effectively eliminated. The proposed unique NAND flash memory cell with a booster line can be used to improve the reliability of nanoscale NAND flash memories.