Points-Over-Threshold Statistics for Post-Retention Read Disturb Reliability in 3D NAND Flash

The 3D NAND Flash memories are known to be the preferred storage media in Solid State Drives applications both for consumer and enterprise scenario. Modeling their reliability in different working corners is a mandatory task for the deployment of system-level management routines that do not compromise the performance and reliability of the drive. Dedicated parametric statistical models have been developed so far to capture the evolution of the memory reliability, although limiting the description to an average behavior rather than extreme cases that can disrupt the drive’s functionality. In this work, for the first time we employ an extreme statistics tool, namely the Points-Over-Threshold method, to characterize the post-retention read disturb reliability of a 3D NAND Flash chip. Such technique proved that the die reliability characterized through extreme events analysis can be predicted using a low number of samples and generally holds good prediction features for distribution tails events.