Intrinsic Channel Mobility of Amorphous, In–Ga–Zn–O Thin-Film Transistors by a Gated Four-Probe Method

Author

Mativenga, Mallory ; Sungjin An ; Suhui Lee ; Jaegwang Um ; Di Geng ; Mruthyunjaya, Ravi K. ; Heiler, Gregory N. ; Tredwell, Timothy John ; Jin Jang

Author_Institution

Dept. of Inf. Display, Kyung Hee Univ., Seoul, South Korea

Volume

61

Issue

6

fYear

2014

fDate

41791

Firstpage

2106

Lastpage

2112

Abstract

Intrinsic mobility and intrinsic channel resistance (R_CH) of amorphous, In-Ga-Zn-O (a-IGZO) thin-film transistors (TFTs) with varying channel length (L) are investigated using a gated four-probe back-channel-etched TFT design. The intrinsic R_CH is found to decrease from ~500 to ~250 kΩ per unit area by increasing V_GS from 10 to 20 V. The intrinsic mobility is ~17 cm²/V·s, which is about 20% higher than that derived from the normal two-point probe measurements. Source and drain parasitic resistance (R_PAR) of the a-IGZO TFTs is found to be of the same order of magnitude as the R_CH-which is different from hydrogenated amorphous-silicon (a-Si:H) TFTs, where TFT operation is dominated by R_PAR.

Keywords

amorphous semiconductors; gallium compounds; indium compounds; semiconductor device models; thin film transistors; zinc compounds; In-Ga-Zn-O; back-channel-etched TFT design; gated four-probe method; hydrogenated amorphous-silicon; intrinsic channel mobility; intrinsic channel resistance; intrinsic mobility; resistance 250 kohm; resistance 500 kohm; thin-film transistors; two-point probe measurements; voltage 10 V; voltage 20 V; Electric potential; Electrical resistance measurement; Electrodes; Logic gates; Probes; Resistance; Thin film transistors; a-IGZO; a-Si:H; channel resistance; gated four probe (GFP); intrinsic mobility; parasitic resistance; thin-film transistor (TFT); thin-film transistor (TFT).;

fLanguage

English

Journal_Title

Electron Devices, IEEE Transactions on

Publisher

ieee

ISSN

0018-9383

Type

jour

DOI

10.1109/TED.2014.2318611

Filename

6809168