Browsing by Author "Huang, Bo-Wen"

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Bias Temperature Instabilities for High-kappa HfO2 LTPS-TFTs With Dual Plasma Treatment
(2016-03)
Wu, Chien-Hung
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Huang, Bo-Wen
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Chang, Kow-Ming
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Chang, Ting-Chia
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Wang, Shui-Jinn
This study is the first to investigate different reliability mechanisms of high-performance low-temperature polycrystalline silicon thin-film transistors (TFTs) with a HfO2 gate dielectric before and after dual plasma treatment (DPT) under various bias temperature instability (BTI) stresses. DPT samples under positive bias temperature instability (PBI) and negative bias temperature instability (NBI) stresses exhibited different degradation phenomena because of the negative polarity trapped oxide charges and positive fixed oxide charges (Si+), respectively. In addition, experimental data exhibited better reliability immunity for PBI stress than NBI stress after DPT. Furthermore, we raised the temperature to clearly observe the effect of the PBTI stress analysis for samples with and without DPT. Extracted measurement results showed distinct time evolutions of the interface state densities (Nit) for samples with and without DPT, revealing the different mechanisms of Nit generation with and without DPT. Finally, we proposed a novel reliability mechanism called the quasi reaction-diffusion model to explain the generation of Delta N-it, which also explains the unclear phenomena of mobility boost.
Electrical Improvement of MIS Capacitor with HfAlOx Gate Dielectrics Treated by Dual Plasma Treatment
(2012)
Deng, I-Chung
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Chang, Kow-Ming
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Chang, Ting-Chia
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Chang, Po-Chun
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Huang, Bo-Wen
High dielectric constant materials (high-k) such as Hf-based thin films are the promising candidates for 45-nm CMOS technology. It has been described that nitridation processes could improve thermal stability and dielectric constants of Hf-based dielectrics. Furthermore, fluorine incorporation into high-k dielectric was also proposed in order to suppress leakage current and passivate defects. In this study, we examined dual plasma treatment (CF4 pretreatment and N-2 post-treatment) on HfAlOx thin films in order to improve electrical characteristics. Based on our experimental results, HfAlOx Metal-Insulator-Semiconductor (MIS) capacitor properties such as capacitance density, gate leakage current density, and hysteresis could be successfully improved. Compared to untreated samples, capacitance is 42.5% higher and gate leakage is suppressed about three orders when dual plasma treatment is used. According to this study, dual plasma treatment would be an effective technology to improve the electrical characteristic of HfAlOx thin films.
Improvement on Interface Quality and Reliability Properties of HfAlOx MIS Capacitor with Dual Plasma Treatment
(2012)
Chang, Kow-Ming
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Chang, Ting-Chia
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Chang, Po-Chun
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Huang, Bo-Wen
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Wu, Chien-Hung
HfO2 is considered a promising gate dielectric material for sub-45 nm CMOS technology. It has been reported that incorporate Al into HfO2 forming Hf aluminates in order to increase the crystallization temperature. However, the growth of the low-k interfacial layer at high-k/Si interface during high-k dielectric deposition would result in reliability degradation. Recently, incorporating nitrogen into HfAlOx gate dielectrics has beneficial effect on reliability performance. In addition, fluorine incorporation into high-k dielectrics also could have several improvements. In this study, dual plasma (CF4 pre-treatment and N-2 post-treatment) was performed on HfAlOx MIS capacitor in order to improve interface quality and the reliability properties. According to our experimental results, dual plasma treatment could improve interface quality and enhance reliability properties of HfAlOx thin films.
Investigation of Gate-Stacked In-Ga-Zn-O TFTs with Ga-Zn-O Source/Drain Electrodes by Atmospheric Pressure Plasma-Enhanced Chemical Vapor Deposition
(2018-03-01)
Wu, Chien-Hung
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Chang, Kow-Ming
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Chen, Yi-Ming
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Huang, Bo-Wen
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Zhang, Yu-Xin
Atmospheric pressure plasma-enhanced chemical vapor deposition (AP-PECVD) was employed for the fabrication of indium gallium zinc oxide thin-film transistors (IGZO TFTs) with high transparent gallium zinc oxide (GZO) source/drain electrodes. The influence of post-deposition annealing (PDA) temperature on GZO source/drain and device performance was studied. Device with a 300 degrees C annealing demonstrated excellent electrical characteristics with on/off current ratio of 2.13x10(8), saturation mobility of 10 cm(2)/V-s, and low subthreshold swing of 0.2 V/dec. The gate stacked LaAlO3/ZrO2 of AP-IGZO TFTs with highly transparent and conductive AP-GZO source/drain electrode show excellent gate control ability at a low operating voltage.
Investigation of Microwave Assisted Annealing on AP-PECVD Fabricated In-Ga-Zn-O Thin Film Transistors under Positive Bias Temperature Stress
(2016)
Wu, Chien-Hung
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Huang, Bo-Wen
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Chang, Kow-Ming
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Cheng, Chia-Yao
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Chen, Hsin-Ying
In this paper, microwave assisted annealing (MWAA) technique on atmospheric pressure plasma-enhanced chemical vapor deposition (AP-PECVD) fabricated indium-gallium-zinc-oxide thin-film transistors (IGZO TFTs) is investigated for the first time. MWAA with 300W for 100sec treatment on AP-IGZO TFTs have been fabricated successfully and show excellent electrical characteristics including a VTH of -1.23 V, SS of 0.18 V/dec, mu FE of 17.4 cm2/V-s, and Ion/Ioff ratio of 8.14 106. Stretched exponential time dependence model is used to analyze the mechanism of AP-IGZO TFTs under PBTI stress. Accordingly, chemisorption model for oxygen adsorption at AP-IGZO backchannel with and without MWAA is proposed to explain the mechanism under PBTI stress.
The Investigation for In-Ga-Zn-O TFTs with Post Deposition of in-situ Ar/H-2 Plasma Treatment by Atmospheric Pressure Plasma Jet
(2016)
Chang, Kow-Ming
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Huang, Bo-Wen
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Wu, Chien-Hung
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Chen, Hsin-Ying
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Zheng, You-Xian
Atmospheric pressure plasma-enhanced chemical vapor deposition (AP-PECVD) was applied for the fabrication of amorphous indium gallium zinc oxide thin-film transistors (a-IGZO TFTs). In this work, a-IGZO TFTs fabricated by AP-PECVD technique were firstly treated by post deposition of in-situ Ar/H-2 plasma with atmospheric pressure plasma Jet (APPJ). Compared to without plasma treatment, samples with the post in-situ Ar/H-2 plasma treatment on IGZO active layer exhibited higher mobility of 20.12 cm(2)/V.S, V-T of 1.11 V, lower subthreshold swing of 93 mV/decade, higher I-on/I-off of 5.34x10(7). The excellent IGZO TFTs fabricated by AP-PECVD technique also show highly transparent characteristics.
The Performance Improvement of N-2 Plasma Treatment on ZrO2 Gate Dielectric Thin-Film Transistors with Atmospheric Pressure Plasma-Enhanced Chemical Vapor Deposition IGZO Channel
(2016-06)
Wu, Chien-Hung
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Huang, Bo-Wen
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Chang, Kow-Ming
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Wang, Shui-Jinn
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Lin, Jian-Hong
The aim of this paper is to illustrate the N-2 plasma treatment for high-kappa ZrO2 gate dielectric stack (30 nm) with indium-gallium-zinc-oxide (IGZO) thin-film transistors (TFTs). Experimental results reveal that a suitable incorporation of nitrogen atoms could enhance the device performance by eliminating the oxygen vacancies and provide an amorphous surface with better surface roughness. With N-2 plasma treated ZrO2 gate, IGZO channel is fabricated by atmospheric pressure plasma-enhanced chemical vapor deposition (AP-PECVD) technique. The best performance of the AP-PECVD IGZO TFTs are obtained with 20 W-90 sec N-2 plasma treatment with field-effect mobility (mu(FET)) of 22.5 cm(2)/V-s, subthreshold swing (SS) of 155 mV/dec, and on/off current ratio (I-on/I-off) of 1.49x10(7).
Using dual plasma treatment to improve electrical characteristics and reduce flicker noise of high-kappa HfO2 LTPS-TFTs
(2015-09-01)
Chang, Kow-Ming
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Huang, Bo-Wen
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Wu, Chien-Hung
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Deng, I-Chung
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Chang, Ting-Chia
This study demonstrated the application of a dual plasma treatment to low-temperature polycrystalline-silicon thin-film transistors (LTPS-TFTs) comprising a self-aligned phosphorus implantation source and drain, high-kappa HfO2 gate dielectric, and aluminum metal gate. The dual plasma treatment involves a pre-deposition CF4 plasma treatment at a high-kappa/poly-Si interface and post-deposition N-2 plasma treatment at a high-kappa HfO2 gate dielectric; this treatment enables reducing the interface-trap-state defects at the high-kappa/poly-Si interface, grain boundary traps in the poly-Si channel film, and oxygen vacancy V-o in the high-kappa HfO2 gate dielectric. Thus, LTPS-TFTs with dual plasma treatment demonstrate excellent electrical characteristics such as threshold voltage, subthreshold swing, transconductance, driving current, and on/off current ratio. Flicker noise, also referred to as 1/f noise, caused by fluctuations of carriers transported in the grain boundary and the trapped carriers per unit oxide volume (N-t) can be suppressed. Therefore, high performance LTPS-TFTs subjected to dual plasma treatment can be appropriately applied to active matrix liquid phase-crystal display on system-on-panel technology. (C) 2015 Elsevier Ltd. All rights reserved.
Using KrF ELA to Improve Gate-Stacked LaAlO3/ZrO2 Indium Gallium Zinc Oxide Thin-Film Transistors with Novel Atmospheric Pressure Plasma-Enhanced Chemical Vapor Deposition Technique
(2018-03-01)
Wu, Chien-Hung
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Chang, Kow-Ming
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Chen, Yi-Ming
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Huang, Bo-Wen
;
Zhang, Yu-Xin
Atmospheric pressure plasma-enhanced chemical vapor deposition (AP-PECVD) technique and KrF excimer laser annealing (ELA) were employed for the fabrication of indium gallium zinc oxide thin-film transistors (IGZO-TFTs). Device with a 150 mJ/cm(2) laser annealing densities demonstrated excellent electrical characteristics with improved on/off current ratio of 4.7x10(7), high channel mobility of 10 cm(2)/V-s, and low subthreshold swing of 0.15 V/dec. The improvements are attributed to the adjustment of oxygen vacancies in the IGZO channel to an appropriate range of around 28.3% and the reduction of traps at the high-k/IGZO interface.