Lateral charge migration induced abnormal read disturb in 3D charge-trapping NAND flash memory

Abstract

Abnormal read disturb (RD) has been investigated in three-dimensional (3D) charge-trapping NAND flash memory. Similar to traditional 2D NAND, RD will cause more error bits right after programming. However, after short-time retention, it has weak effects on error bits; more importantly, after long-time retention, a part of error bits can be recovered. With special coding designs in chip characterizations and TCAD simulations, it is concluded that lateral charge migration could be dominant mechanism for abnormal RD, which can be utilized to prolong lifetime of 3D NAND-based memory system for cold storage applications.