Novel source-controlled self-verified programming for multilevel EEPROMs

In this work, a new source-controlled self-verified (SCSV) programming method for multilevel storage in EEPROM is discussed. Multilevel storage is a cost-effective approach to improve storage capacity and reduce bit-cost. However, the reduced interlevel margin impacts the reliability and available endurance. The new SCSV programming approach using simultaneous programming and verification can control threshold voltages by different source voltages. Linear relationship between threshold voltage and source voltage is obtained. Furthermore, the endurance of multilevel storage is extended up to 10/sup 6/ cycles. The accurate control of threshold voltage improves the reliability of multilevel EEPROM's. Therefore, the SCSV programming approach is a promising technique for future high-density and low-cost EEPROM applications.