Novel operation schemes to improve device reliability in a localized trapping storage SONOS-type flash memory

Over erasure, charge gain in the low Vt state, and charge loss in the high Vt state are found to be the most severe reliability issues in a localized trapping storage flash memory cell. In this paper, based on our understanding of physical mechanisms, we demonstrate that by adding vertical electrical field treatments during program/erase operations, the over erasure and data retentivities in high/low Vt states are significantly improved.