Novel high-density and high-speed NAND-type electrical erasable programmable read only memory

A new NAND-type electrical erasable programmable read only memory (EEPROM), which employs (1) the novel in-cell temporary storage (ICTS) technique and (2) the novel multiple-wordline parallel programming (MWPP) method, is proposed to reduce the unit cell size and decrease the overall programming time. The ICTS approach latches input data directly to the selected EEPROM cells by an inverted channel with different input bitline voltages. After all the selected cells are latched to individual data, the MWPP method simultaneously raises all selected wordlines to high voltage to perform FN tunneling for parallel programming. The equivalent byte programming time is considerably reduced by employing parallel programming. The high-speed and high-density features further reduce the EEPROM testing cost for manufacturers and save programming time and cost for system providers.