On the Origin of Improved Charge Transport in Double-Gate In–Ga–Zn–O Thin-Film Transistors: A Low-Frequency Noise Perspective

Author

Yong Xu ; Chuan Liu ; Amegadez, Paul Seyram K. ; Gi-Seong Ryu ; Huaixin Wei ; Balestra, Francis ; Ghibaudo, Gerard ; Yong-Young Noh

Author_Institution

Dept. of Energy & Mater. Eng., Dongguk Univ., Seoul, South Korea

Volume

36

Issue

10

fYear

2015

Firstpage

1040

Lastpage

1043

Abstract

Low-frequency noise (LFN) in double-gate (DG) In-Ga-Zn-O (IGZO) thin-film transistors (TFTs) is studied to investigate the origin of performance improvement. We found that thinning down the IGZO film enhances such improvements. With 7-nm IGZO, the mobility is raised by a factor of 3.77, and the subthreshold slope is reduced to 0.17 V/decade from single-gate to DG mode. Device simulations show that bulk transport inside IGZO film emerges as the two gates field effects get coupled. The LFN results reveal a transport transition from surface to bulk and disclose the superior bulk transport that experiences slight phonon scattering with a small Hooge parameter α_H = 4.44 × 10^-3 whereas the surface transport undergoes serious charge trapping with surface trap densities about 2 × 10¹¹ eV^-1cm^-2.

Keywords

II-VI semiconductors; charge exchange; gallium compounds; indium compounds; semiconductor device noise; thin film transistors; zinc compounds; Hooge parameter; IGZO film; InGaZnO; bulk transport; charge transport; charge trapping; double-gate thin-film transistors; low-frequency noise perspective; phonon scattering; size 7 nm; subthreshold slope; surface transport; surface trap densities; transport transition; Dielectrics; Films; Logic gates; Low-frequency noise; Thin film transistors; Double gate; IGZO; low-frequency noise; metal oxide semiconductor; thin-film transistor;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2015.2467164

Filename

7192611