FA Process: Fault Isolation, Mechanisms, & Solutions - Analysis of joint misalignment defects on multi-tier 3D NAND
FA Process: Fault Isolation, Mechanisms, & Solutions - Analysis of joint misalignment defects on multi-tier 3D NAND
Wednesday, November 19, 2025
Summary:
Word line (WL) to memory hole (MH) shorts are a common defect in 3D NAND Flash Memory devices. The introduction of multi-tier 3D NAND technologies brings with it unique defect modes, and in this paper, we studied a specific subset of WL-MH shorts unique to multi-tier 3D NAND. These defects specifically affect the WLs beneath the joint (where the upper and lower tiers connect). Physical analysis of the defects determined that misalignment between the upper memory hole (UMH) and lower memory hole (LMH) is the root cause of these shorts
Word line (WL) to memory hole (MH) shorts are a common defect in 3D NAND Flash Memory devices. The introduction of multi-tier 3D NAND technologies brings with it unique defect modes, and in this paper, we studied a specific subset of WL-MH shorts unique to multi-tier 3D NAND. These defects specifically affect the WLs beneath the joint (where the upper and lower tiers connect). Physical analysis of the defects determined that misalignment between the upper memory hole (UMH) and lower memory hole (LMH) is the root cause of these shorts