Design considerations in scaled SONOS nonvolatile memory devices

Scaling the programming voltage, while still maintaining 10-year data reten tion time, has always been a big challenge for polysilicon-oxide-nitride-ox ide-silicon (SONOS) researchers. We describe progress in the design and sca ling of SONGS nonvolatile memory devices. We have realized -9 + 10 V (1 ms) programmable SONGS devices ensuring 10-year retention time after 10: erase /write cycles at 85 degreesC. Deuterium anneals, applied in SONGS device fa brication for the first time. improves the endurance characteristics when c ompared with traditional hydrogen or forming gas anneals. We introduce scal ing considerations and process optimization along with experiments and SONG S device characterization. A field programmable gate array-based measuremen t system is described for the dynamic characterization of SONGS nonvolatile memory devices. (C) 2001 Elsevier Science Ltd. All rights reserved.