Process Improvements for 7th Generation 1Tb Quad-Level Cell 3D NAND Flash Memory in Mass Production

Abstract

Over the past few decades, a greater need for 3D Vertical NAND (V-NAND) flash memory storage capacity has emerged. Compared to its prevailing technical predecessor, a quad-level cell (QLC) NAND flash memory can be a perfect replacement to meet the needs for the higher density and lower cost non-volatile memory market. However, despite these benefits, QLC’s market share has not been growing significantly because of its worse device reliability and slower performance. In this Paper, a new highly mass-producible and highly reliable 1Tb QLC 3D NAND flash memory with 176-word-line (WL) and Cell-Over-Peripheral (COP) architecture along with a number of significant process advancements will be presented.