High performance SONOS memory cells free of drain turn-on and over-erase: compatibility issue with current flash technology

Nonvolatile SONOS memory cells, fabricated by standard flash EEPROM technology are characterized, in comparison with floating gate memory devices. Its programming speed is comparable with the state-of-the-art flash EEPROM cells, while the erase speed is faster and over-erase-free. The SONOS cells do not suffer from the drain turn-on effect, making it is possible to perform parallel multi bit-line programming and to achieve tighter distributions of programmed and erased threshold voltages. These features render SONOS cells attractive for direct utilization in existing flash EEPROM technology with its forward reading scheme.