A Physics-based Model for Long Term Data Retention Characteristics in 3D NAND Flash Memory

Abstract

Charge loss mechanisms during Data retention (DR) in GAA 3D NAND devices, Inter-cell charge loss of electrons in the Charge Trap Layer (CTL), and In-cell charge loss of electrons from tunnel oxide are modeled and analyzed using a physics-based Activated Barrier Double Well Thermionic Emission (ABDWT) model. The measured data retention characteristics for Solid Pattern (SP), of various distribution, sigma $(\sigma)$ of the lower tail of the Cell Voltage Distribution (CVD) has been studied and modeled for various temperatures and programming levels (PL). Checkered pattern (CP) measured long-term data retention characteristics at various temperatures and program levels are modeled for both the loss components. 10 years projection is extrapolated across temperature and programing levels.