Browsing by Author "Huang, Hau-Yuan"

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Effect of the Annealing Ambient on the Electrical Characteristics of the Amorphous InGaZnO Thin Film Transistors
(2012-07-01)
Huang, Yu-Chih
;
Yang, Po-Yu
;
Huang, Hau-Yuan
;
Wang, Shui-Jinn
;
Cheng, Huang-Chung
The influence of the thermal annealing on the amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs) under different ambient gases has been systematically addressed. The chemical bonding states and transfer characteristics of a-IGZO TFTs show evident dependence on the annealing ambient gas. For the a-IGZO TFTs in the oxygen ambient annealing at 250 degrees C for 30 mins exhibited a maximum field effect mobility (max mu(FE)) of 9.36 cm(2)/V . s, on/off current ratio of 6.12 X 10(10), and a subthreshold slope (SS) of 0.21 V/decade. Respectively, the as-deposited ones without annealing possess a max mu(FE) of 6.61 cm(2)/V . s, on/off current ratio of 4.58 x 10(8), and a SS of 0.46 V/decade. In contrast, the a-IGZO TFTs annealed at 250 degrees C for 30 mins in the nitrogen ambient would be degraded to have a max mu(FE) of 0.18 cm(2)/V . s, on/off current ratio of 2.22 X 10(4), and a SS of 7.37 V/decade, corresponding. It is attributed to the content of the oxygen vacancies, according the x-ray photoelectron spectroscopy (XPS) analyze of the three different samples.
Investigation of LaAlO3/ZrO2/a-InGaZnO thin-film transistors using atmospheric pressure plasma jet
(2014-04-24)
Wu, Chien-Hung
;
Huang, Hau-Yuan
;
Wang, Shui-Jinn
;
Chang, Kow-Ming
;
Hsu, Hsin-Yu
Amorphous indium-gallium-zinc-oxide thin-film transistors (a-IGZO-TFTs) with the LaAlO3/ZrO2 gate dielectric stack employing a novel atmospheric pressure plasma jet process that results in small subthreshold swing and low threshold voltage are proposed and fabricated. The influence of post-deposition annealing (PDA) temperature on LaAlO3/ZrO2 gate dielectric stack and device performance was investigated. The equivalent oxide thickness of the LaAlO3/ZrO2 dielectric stack decreases from 11.5 nm without annealing to 7 nm after a 500 degrees C annealing was applied. The LaAlO3/ZrO2/a-InGaZnO TFT with a 500 degrees C annealing exhibits a small subthreshold swing of 77 mV.dec(-1), a high field-effect mobility of 9 cm(2).V-1.s(-1) and an excellent current ratio of 1.8 x 10(7), which could be attributed to the improved gate dielectric quality by the PDA. The LaAlO3/ZrO2/a-InGaZnO TFTs with excellent gate control ability allow the device to operate at a low operating voltage with low power consumption.
The Influence of NH3 Plasma Treatment on Al2O3/HfO2 Gate Dielectrics of TFTs with Atmospheric Pressure Plasma Jet Deposited IGZO Channel
(2014)
Huang, Hau-Yuan
;
Wu, Chien-Hung
;
Wang, Shui-Jinn
;
Chang, Kow-Ming
;
Hsu, Hsin-Yu
Indium-gallium-zinc-oxide (IGZO) thin-film transistors are fabricated by atmospheric pressure plasma jet (APPJ) technique. HfO2 (25 nm) and Al2O3 (25 nm) are used as the gate dielectric stack. NH3 plasma treatment is applied to optimize the device performance by reducing the gate dielectric leakage and increasing the oxide capacitance. The best performance of the APPJ IGZO TFT is obtained with a 30W-60s NH3 plasma treatment with field-effect mobility of 6.1 cm(2)/V-s, subthreshold swing of 0.19 V/dec, and on/off current ratio of 10(8).