Simultaneous hot-hole injection at drain and source for efficient erase and excellent endurance in SONOS flash EEPROM cells

An efficient erase technique is presented for SONOS EEPROM cells, using the concomitant hot-hole injection (HHI) at the drain and the source. Electrons trapped during the programming are thus fully eliminated throughout the entire channel, securing thereby a satisfactory cell endurance behavior. Additionally in the present HHI scheme the voltage applied at the common bulk terminal enables efficient erase in the entire erase sector. Also, HHI is quantitatively shown much more efficient for erase, compared with Fowler-Nordheim (F-N) tunneling. Finally, the elimination of trapped electrons throughout the entire channel is shown crucial for achieving a satisfactory cell endurance behavior.