Frl. Lin et al., A novel high-density and high-speed NAND-type electrical erasable programmable read only memory, JPN J A P 1, 39(4B), 2000, pp. 2208-2214
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 pro
posed to reduce the unit cell size and decrease the overall programming tim
e. The ICTS approach latches input data directly to the selected EEPROM cel
ls by an inverted channel with different input bitline voltages. After all
the selected cells are latched to individual data, the MWPP method simultan
eously raises all selected wordlines to high voltage to perform FN tunnelin
g for parallel programming. The equivalent byte programming time is conside
rably reduced by employing parallel programming. The high-speed and high-de
nsity features further reduce the EEPROM testing cost for manufacturers and
save programming time and cost for system providers.