Three-dimensional AND flash memory
High-density and high-speed charge-trapping AND flash memory array is fabricated for the first time. A reliability of 104 endurance cycles and uniform program/erase characteristics along with a threshold voltage window >3 V is obtained. The AND array has several advantages, such as high read current drivability regardless of the number of word-lines, immunity to back-pattern dependency, and fast bit-sensing speed based on a parallel connected cell array structure, which are highly appropriate for three-dimensional (3D) stacking. Finally, a novel 3D stacked vertical-AND array is proposed to surpass the limitations of the conventional 3D NAND flash memories.