The charge storage characteristics of ZrO2 nanocrystallite-based charge trap nonvolatile memory

摘要

ZrO2 nanocrystallite-based charge trap flash memory capacitors incorporating a (ZrO2)0.6(SiO2)0.4 pseudobinary high-k oxide film as the charge trapping layer were prepared and investigated.The precipitation reaction in the charge trapping layer,forming ZrO2 nanocrystallites during rapid thermal annealing,was investigated by transmission electron microscopy and X-ray diffraction.It was observed that a ZrO2 nanocrystallite-based memory capacitor after post-annealing at 850 ℃ for 60 s exhibits a maximum memory window of about 6.8 V,good endurance and a low charge loss of ～25％ over a period of 10 years (determined by extrapolating the charge loss curve measured experimentally),even at 85 ℃.Such 850 ℃-annealed memory capacitors appear to be candidates for future nonvolatile flash memory device applications.