13.1 A 1Tb 4b/cell NAND Flash Memory with tPROG=2ms, tR=110µs and 1.2Gb/s High-Speed IO Rate

3D NAND flash memory has enhanced its areal density by more than 50% per year by virtue of the aggressive development of 3D WL stacking technology for the recent three consecutive years [1]–[3]. Also storage market still requires more bits for diverse digital applications. [4]