학술논문

Investigation of Self-Heating Effect in Tree-FETs by Interbridging Stacked Nanosheets: A Reliability Perspective
Document Type
Periodical
Source
IEEE Transactions on Device and Materials Reliability IEEE Trans. Device Mater. Relib. Device and Materials Reliability, IEEE Transactions on. 23(1):58-63 Mar, 2023
Subject
Engineered Materials, Dielectrics and Plasmas
Components, Circuits, Devices and Systems
Power, Energy and Industry Applications
Bridge circuits
Logic gates
Performance evaluation
Degradation
Reliability
Numerical models
Nanoscale devices
Tree-FET
NSFET
self-heating effects
inter-bridge (IB)
threshold voltage (VT) variation
Language
ISSN
1530-4388
1558-2574
Abstract
This work comprehensively investigates the self-heating effects (SHEs) in Tree-FET at 5nm technological nodes. A comparative analysis of Tree-FET with Nanosheet FET (NSFET) shows that the Tree-FET (3-channel+2-bridge) is more or less comparable to the 5-channel NSFET rather than with 3-channel NSFET. An in-depth physics-based study shows that considering only one aspect of increasing ON current is insufficient to judge Tree-FETs for future technological nodes. Targeting these facts, device reliability is demonstrated through numerical simulations showing that Tree-FET outperforms in a self-heating situation, which is a prime concern at a lower technology node. 5-channel NSFET shows $\sim {\textbf {24}}\%$ reduction while Tree-FET ( $\text{H}_{\textbf {IB}}\,\,=$ 25nm) shows only $\sim \textbf {20}\%$ reduction in $I_{\textbf {ON}}$ under self-heating. This is because the bridges create a path to heat removal through electrodes and substrate. The peak temperature difference between channels is $\sim \textbf {23K}$ in Tree-FET, whereas, in the case of other counterparts, it is $\sim \textbf {28K}$ . A comparatively smaller variation in the $\text{V}_{\textbf {T}}$ shift due to the self-heating effect is observed in Tree-FET in order to achieve higher $I_{\textbf {ON}}$ , showing a promising candidate for circuitry that requires a high drive current. A comparative lower gate capacitance implies that Tree-FET may perform well in digital switching applications. Though Tree-FET is not comparable to NSFET for analog applications due to lesser intrinsic gain, it shows a lesser degradation in cut-off frequency $(\sim \textbf {3}\%$ ) compared to 5-channel NSFET under a self-heating environment.