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A Novel Source/Drain Extension Scheme with Laser-Spike Annealing for Nanosheet Field-Effect Transistors in 3D ICs.

Authors :
Lee, Sanguk
Jeong, Jinsu
Kang, Bohyeon
Lee, Seunghwan
Lee, Junjong
Lim, Jaewan
Hwang, Hyeonjun
Ahn, Sungmin
Baek, Rockhyun
Source :
Nanomaterials (2079-4991). Mar2023, Vol. 13 Issue 5, p868. 13p.
Publication Year :
2023

Abstract

This study proposed a novel source/drain (S/D) extension scheme to increase the stress in nanosheet (NS) field-effect transistors (NSFETs) and investigated the scheme by using technology-computer-aided-design simulations. In three-dimensional integrated circuits, transistors in the bottom tier were exposed to subsequent processes; therefore, selective annealing, such as laser-spike annealing (LSA), should be applied. However, the application of the LSA process to NSFETs significantly decreased the on-state current (Ion) owing to diffusionless S/D dopants. Furthermore, the barrier height below the inner spacer was not lowered even under on-state bias conditions because ultra-shallow junctions between the NS and S/D were formed far from the gate metal. However, the proposed S/D extension scheme overcame these Ion reduction issues by adding an NS-channel-etching process before S/D formation. A larger S/D volume induced a larger stress in the NS channels; thus, the stress was boosted by over 25%. Additionally, an increase in carrier concentrations in the NS channels improved Ion. Therefore, Ion increased by approximately 21.7% (37.4%) in NFETs (PFETs) compared with NSFETs without the proposed scheme. Additionally, the RC delay was improved by 2.03% (9.27%) in NFETs (PFETs) compared with NSFETs using rapid thermal annealing. Therefore, the S/D extension scheme overcame the Ion reduction issues encountered in LSA and significantly enhanced the AC/DC performance. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
20794991
Volume :
13
Issue :
5
Database :
Academic Search Index
Journal :
Nanomaterials (2079-4991)
Publication Type :
Academic Journal
Accession number :
162385963
Full Text :
https://doi.org/10.3390/nano13050868