Enabling 3D NAND Trench Cells for Scaled Flash Memories

Abstract

3D Trench cells with a vertical flat channel have been proposed to increase the cell density over 3D NAND gate-all-around (GAA). In this work, we investigate the device characteristics of Trench cells. In absence of curvature, Trench cells exhibit inferior program and erase in comparison to a GAA reference. However, the memory window of Trench cells is significantly improved with channel width scaling, gate stack engineering and metal gate integration. This study also provides a basis for design and fabrication of future ultradense 3D NAND memories based on the Trench architecture.