Systematic Analysis of Spacer and Gate Length Scaling on Memory Characteristics in 3D NAND Flash Memory

Abstract

This study investigates the impact of oxide/nitride (ON) pitch scaling on the memory performance of 3D NAND flash memory. We aim to enhance 3D NAND flash memory by systematically reducing the spacer length (Ls) and gate length (Lg) to achieve improved memory characteristics. Using TCAD simulations, we evaluate the effects of Ls and Lg scaling on the program speed, erase speed, and Z-interference. Furthermore, we examine the influence of concave and convex channel structures in the context of Ls and Lg scaling. By analyzing the distributions of electron and hole-trapped charges, we provide insights into optimizing the trade-offs between the memory window and retention characteristics. This research offers valuable guidelines for improving the reliability and performance of 3D NAND flash memory through a systematic analysis of spacer and gate length scaling.

Keywords

• 3D NAND flash memory
• ON pitch scaling
• gate length
• spacer length
• memory window
• z-interference