Demonstration of Asymmetric Gate-Oxide Thickness Four-Terminal FinFETs Having Flexible Threshold Voltage and Good Subthreshold Slope

Author

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

Author_Institution

IMEC, Leuven

Volume

28

Issue

3

fYear

2007

fDate

3/1/2007 12:00:00 AM

Firstpage

217

Lastpage

219

Abstract

Flexibly controllable threshold-voltage (V_th) asymmetric gate-oxide thickness (T_ox) four-terminal (4T) FinFETs with HfO₂ [equivalentoxidethickness(EOT)=1.4 nm] for the drive gate and HfO₂+thick SiO₂ (EOT=6.4-9.4 nm) for the V_th-control gate have been successfully fabricated by utilizing ion-bombardment-enhanced etching process. Owing to the slightly thick V_th-control gate oxide, the subthreshold slope (S) is significantly improved as compared to the symmetrically thin T_ox 4T-FinFETs. As a result, the asymmetric T_ox 4T-FinFETs gain higher I_on than that for the symmetrically thin T_ox 4T-FinFETs under the same I_off conditions

Keywords

MOSFET; etching; hafnium compounds; silicon compounds; voltage control; 1.4 nm; 6.4 to 9.4 nm; HfO₂; SiO₂; asymmetric gate-oxide thickness; equivalent oxide thickness; flexible threshold voltage; four-terminal FinFET; ion-bombardment-enhanced etching process; subthreshold slope; threshold voltage-control gate oxide; Circuit optimization; Etching; Fabrication; FinFETs; Hafnium oxide; Integrated circuit technology; Microelectronics; Thickness control; Threshold voltage; Voltage control; Asymmetric gate-oxide thickness; FinFET; four-terminal (4T) FinFET; ion-bombardment-enhanced etching (IBEE); subthreshold slope; threshold-voltage control;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2007.891303

Filename

4114576