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

Nonvolatile SONGS memory cells, fabricated by standard flash EEPROM technol ogy are characterized, in comparison with floating gate memory devices. Its programming speed is comparable with the state-of-the-art flash EEPROM cel ls, while the erase speed is faster and over erase free. The SONGS 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 o f programmed and erased threshold voltages. These features render SONGS cel ls attractive for direct utilization in existing flash EEPROM technology wi th its forward reading scheme.