A high density high performance cell for 4M bit full feature electrically erasable/programmable read-only memory

A new electrically erasable / programmable read-only memory (EEPROM) cell structure is proposed, which achieves a high capacitive coupling ratio of more than 0.8 in a small cell size of 11.25 µm 2 using 0.6 µm lithography. This new cell has sufficient cell threshold windows which extend to more than 5 volts and a programmed cell current of more than 30 µA at a program voltage of 14 volts. The cell endurance is more than 10 5 erase/write cycles. Using this cell structure, a 4-mega-bit full-feature EEPROM of high performance and high reliability can be acquired.