Improved retention and cycling characteristics of MONOS memory using Charge-Trapping-Engineering

The shallow trap energy in SONOS charge-trapping flash (CTF) is the fundamental challenge for required good retention, especially at elevated temperatures. Although the high temperature retention can be improved by BE-SONOS, this is traded off the slow erase speed. To address these issues, we have fabricated a new charge-trapping-engineered flash (CTEF) using deep trapping high-dielectric to replace Si₃N₄. At 150degC, the CTEF device shows a large 5.6 V initial memory window and a 3.8 V 10-year extrapolated retention for 4-bits/cell MLC, under very fast 100 s and plusmn16 V program/erase condition.