摘要
This paper describes a 5-V-only 4-Mb (512K×8 b) nand EEPROM with tight programmed threshold voltage (V t ) distribution, controlled by a novel program verify technique. A tight programmed V t distribution width of 0.8 V for the 4-Mb cell array is achieved. By introducing a compact row-decoder circuit, the die size of 7.28 mm × 15.31 mm is accomplished using 1.0-pm design rules. A unique twin p-well structure has made it possible to realize low-power 5-V-only erase/program operation easily and 100K cycle endurance. © 1991 IEEE