Read Current Instability Arising from Random Telegraph Noise in Localized Storage, Multi-Level SONOS Flash Memory

Program/erase cycling stress induced read current fluctuations arising from random telegraph noise (RTN) in a localized storage, multi-level nitride flash memory (SONOS) is explored. Our study shows that localized charge storage significantly enhances RTN. The amplitude of RTN varies in different program levels of a multi-level cell. The broadening of read current distribution due to RTN is characterized and modeled. Improvement of bottom oxide robustness can reduce the read current fluctuations