QLC Programmable 3D Ferroelectric NAND Flash Memory by Memory Window Expansion using Cell Stack Engineering. - Sunghyun Yoon; Sung-In Hong; Daehyun Kim; Garam Choi; Young Mo Kim; Kyunghoon Min; Seiyon Kim; Myung-Hee Na; Seonyong Cha (VLSI Technology and Circuits, 2023)