Experimental Investigation of Optimum Gate Workfunction for CMOS Four-Terminal Multigate MOSFETs (MUGFETs)

Author

Masahara, Meishoku ; Surdeanu, Radu ; Witters, Liesbeth ; Doornbos, Gerben ; Nguyen, Viet H. ; Van den Bosch, Geert ; Vrancken, Christa ; Jurczak, Malgorzata ; Biesemans, Serge

Author_Institution

IMEC, Leuven

Volume

54

Issue

6

fYear

2007

fDate

6/1/2007 12:00:00 AM

Firstpage

1431

Lastpage

1437

Abstract

This paper describes a comprehensive study on the optimum gate workfunction (GWF) for four-terminal-driven multigate MOSFETs (4T-MUGFETs). CMOS 4T-MUGFETs with HfO₂ high-kappa gate insulator (EOT=1.4 nm) and TiN metal gate have been experimentally demonstrated, and their optimum GWF has been thoroughly investigated. Based on the investigation, it was concluded that the optimum GWF is around 4.32 eV for the NMOS 4T-MUGFETs while 5.17 eV for PMOS 4T-MUGFETs. The reason for the existence of the optimum GWF for the 4T-MUGFETs has been comprehensively explained on the basis of the universal relationship between the initial Vth in the 3T-mode (V_thDG), V_th in the 4T-mode (V_th(G1)), and the second gate bias in the 4T-mode (V_g2)

Keywords

MOSFET; hafnium compounds; high-k dielectric thin films; titanium compounds; work function; CMOS 4T-MUGFET; HfO₂; TiN; four-terminal-driven multigate MOSFET; high-K gate insulator; optimum gate workfunction; subthreshold slope; threshold voltage control; Energy consumption; Fabrication; Hafnium oxide; Insulation; MOSFETs; Metal-insulator structures; Microelectronics; Threshold voltage; Tin; Voltage control; Four-terminal (4T) MUGFET; gate workfunction (GWF); high- $kappa$; metal gate; multigate MOSFET (MUGFET); subthreshold slope; threshold voltage control;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/TED.2007.896324

Filename

4215182