OBIRCH Hotspot Detection via MH-to-WL Biasing for 3D NAND Memory Hole Defect Isolation

Abstract

In Flash semiconductor technology, NAND-type 3D Flash memory continues to stack up more Word-Line (WL) layers e.g. 2XX for 8th and 9th generation 3D NAND. The complexity of interconnect structures and the density of metal layers have increased dramatically. This evolution introduces new failure modes that are difficult to detect and isolate using conventional techniques. This paper presents a novel biasing approach that enhances OBIRCH sensitivity by targeting Memory Hole (MH)-to-WL interaction. Experimental results on advanced NAND-type 3D Flash memory devices demonstrate that this technique enables repeatable hotspot detection after destructive sample preparation. The finding established a robust and novel solution for detecting MH defects in highly scaled memory technologies.