Revisiting Charge Trapping/Detrapping in Flash Memories From a Discrete and Statistical Standpoint—Part II: On-Field Operation and Distributed-Cycling Effects

摘要

Starting from the theoretical background on the detrapping process in nanoscale Flash memories given in Part I of this paper [1], we address here the effect of idle periods, temperature, and program/erase cycles on the spectral distribution of detrapping events and, in turn, on threshold-voltage instabilities appearing during a data retention time stretch. In so doing, we come to a comprehensive model able to deal with threshold-voltage instabilities from whatever on-field usage or testing scheme of the memory array, carefully accounting for both charge trapping and detrapping, and reproducing distributed-cycling effects. The model represents a valuable tool for the predictive reliability analysis of Flash technologies and for the development of accelerated experimental schemes for the assessment of post-cycling thereshold-voltage instabilities coming from charge detrapping.