| 摘要 |
PROBLEM TO BE SOLVED: To minimize program disturb in flash memories.SOLUTION: To reduce program disturb in a NAND Flash memory cell string where no programming from an erased state is desired, a local boosted channel inhibit scheme is used. In the local boosted channel inhibit scheme, a selected memory cell in a NAND string where no programming is desired, is decoupled from the other cells in the NAND string. This allows a channel of the decoupled cell to be locally boosted to a voltage level sufficient for inhibiting F-N tunneling when a corresponding wordline is raised to a programming voltage. Because of the high boosting efficiency, pass voltage applied to gates of the remaining memory cells in the NAND string can be reduced compared to the prior art, thereby minimizing program disturb while allowing random page programming. |
