Distributed Cycling in Charge Trap-Based 3D NAND Arrays: Model and Qualification Tests Implications

Abstract

In this work, we present the first electrical characterization and modeling of the impact on long-term data retention of distributed cycling in charge trap (CT) 3D NAND arrays. Dependence on Program/Erase cycling conditions of trapassisted tunneling (TAT), charge detrapping, and lateral charge migration (LCM) are experimentally evaluated and modeled. It is demonstrated that post-cycling TAT degradation depends only on the overall cycling dose and not on cycling temperature nor on the delays in-between each Program/Erase operation. On the other hand, charge detrapping follows the same time and temperature dynamics as the ones observed in floating-gate NAND arrays. Finally, LCM is observed to improve with increasing cycling dose and cycling temperature but to be negligibly dependent on the cycling duration. Results are a cornerstone in designing accelerated cycling tests for CT 3D NAND arrays qualification.