Effects of low-temperature (120 °C) annealing on the carrier concentration and trap density in amorphous indium gallium zinc oxide thin film transistors

Journal Article · Sun Dec 28 00:00:00 EST 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4904843· OSTI ID:22399187

Kim, Jae-sung; Piao, Mingxing; Jang, Ho-Kyun; Kim, Gyu-Tae ^[1]; Oh, Byung Su ^[1]; Joo, Min-Kyu ^[1]; Ahn, Seung-Eon ^[1]

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1. School of Electrical Engineering, Korea University, Seoul 136-701 (Korea, Republic of)

We report an investigation of the effects of low-temperature annealing on the electrical properties of amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs). X-ray photoelectron spectroscopy was used to characterize the charge carrier concentration, which is related to the density of oxygen vacancies. The field-effect mobility was found to decrease as a function of the charge carrier concentration, owing to the presence of band-tail states. By employing the transmission line method, we show that the contact resistance did not significantly contribute to the changes in device performance after annealing. In addition, using low-frequency noise analyses, we found that the trap density decreased by a factor of 10 following annealing at 120 °C. The switching operation and on/off ratio of the a-IGZO TFTs improved considerably after low-temperature annealing.

• OSTI ID: 22399187
• Journal Information: Journal of Applied Physics, Vol. 116, Issue 24; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANNEALING
CARRIER MOBILITY
CHARGE CARRIERS
CONCENTRATION RATIO
DENSITY
ELECTRICAL PROPERTIES
GALLIUM COMPOUNDS
INDIUM COMPOUNDS
THIN FILMS
TRANSISTORS
TRAPS
VACANCIES
X-RAY PHOTOELECTRON SPECTROSCOPY
ZINC OXIDES