Short channel enhanced degradation during discharge of flash EEPROM memory cell

A new mode of channel length dependent degradation due to band-to-band tunneling current during the discharge of short channel flash memory device is discussed. The degradation is due to the holes created by band-to-band tunneling current and accelerated by the lateral electric field. The holes gain enough energy, are injected into the oxide and cause damage. The amount of degradation increases significantly as channel length decreases. This could be a fundamental limitation to the scaling of flash memory cells. A new discharge method is proposed to inhibit the hot hole injection and to obtain precise discharged Vt control