A highly manufacturable 128K flash EEPROM was developed based on a new cell. Programming is achieved through hot-electron injection and erasing through electron tunneling from the floating gate to the drain. The cell is 20 percent larger than an EPROM cell and contains an integral series transistor which ensures self-limited erasing, reduces leakage, and increases the cell current. The flash EEPROM device can withstand thousands of program/erase cycles. Endurance failures are due to threshold window closing caused by electron trapping in the gate oxide. Typical erase time is 1 s to clear the entire memory.