Version 1
: Received: 8 October 2021 / Approved: 19 October 2021 / Online: 19 October 2021 (10:12:01 CEST)
Version 2
: Received: 21 October 2021 / Approved: 21 October 2021 / Online: 21 October 2021 (12:12:18 CEST)
Lee, J.; Yoon, D.-G.; Sim, J.-M.; Song, Y.-H. Impact of Residual Stress on a Polysilicon Channel in Scaled 3D NAND Flash Memory. Electronics2021, 10, 2632.
Lee, J.; Yoon, D.-G.; Sim, J.-M.; Song, Y.-H. Impact of Residual Stress on a Polysilicon Channel in Scaled 3D NAND Flash Memory. Electronics 2021, 10, 2632.
Abstract
The effects of residual stress in a tungsten gate on a polysilicon channel in scaled 3D NAND flash memories were investigated using a technology computer-aided design simulation. The NAND strings with respect to the distance from the tungsten slit were also analyzed. The scaling of the spacer thickness and hole diameter induced compressive stress on the polysilicon channel. Moreover, the residual stress of polysilicon in the string near the tungsten slit had greater compressive stress than the string farther away. The increase in compressive stress in the polysilicon channel degraded the Bit-Line current (Ion) because of stress-induced electron mobility deterioration. Moreover, a threshold voltage shift (△Vth) occurred in the negative direction because of conduction band lowering.
Keywords
3D NAND; hole profile; mechanical stress; polysilicon channel; scaling; TCAD
Subject
ENGINEERING, Electrical & Electronic Engineering
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Juyoung Lee
