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

Abstract

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.