Browsing by Author "Hsu, Hsiao-Hsuan"

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A Flexible IGZO Thin-Film Transistor With Stacked TiO2-Based Dielectrics Fabricated at Room Temperature
(2013-06-01)
Hsu, Hsiao-Hsuan
;
Chang, Chun-Yen
;
Cheng, Chun-Hu
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This letter demonstrates the feasibility of full room temperature InGaZnO thin-film transistor (TFT) using trilayer gate dielectric on flexible substrate. Through integrating high-kappa SiO2/TiO2/SiO2 (STS) gate-stack as well as InGaZnO channel thickness modulation, the resulting flexible indium-gallium-zinc oxide (IGZO)/STS TFTs show low threshold voltage of 0.5 V, small subthreshold swing of 0.129 V/decade, high field effect mobility of 76 cm(2)/Vs, and good I-ON/I-OFF ratio of 6.7 x 10(5), which have the potential for the application of high-resolution flexible display.
A Low Operating Voltage IGZO TFT Using LaLuO3 Gate Dielectric
(2013)
Chou, Kun-I
;
Hsu, Hsiao-Hsuan
;
Cheng, Chun-Hu
;
Lee, Kai-Yu
;
Li, Shang-Rong
This study proposes a low operation voltage indium-gallium-zinc oxide (IGZO) thin-film transistor using a high-kappa lanthanum-lutetium oxide as the gate dielectric. It is the first time to integrate the high-kappa LaLuO3 into an IGZO TFT. The resulting LaLuO3/IGZO TFT shows a low threshold voltage of 0.32 V, a small sub-threshold swing of 310 mV/decade and an acceptable mobility (mu(FE)) of 6.6 cm(2)/V-s. The low V-T and small SS allow device operation voltage below 2.5 V.
Amorphous bilayer TiO2-InGaZnO thin film transistors with low drive voltage
(2014-09-01)
Hsu, Hsiao-Hsuan
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Cheng, Chun-Hu
;
Chiou, Ping
;
Chiu, Yu-Chien
;
Chang, Chun-Yen
This paper describes a high-performance thin-film transistor (TFT) fabricated using TiO2 and InGaZnO semiconducting layers. Favorable transistor characteristics, including a low threshold voltage of 0.45 V, a small subthreshold swing of 174 mV/decade, and a high field effect mobility of 19 cm(2)/V s at a low drive voltage of <2 V, were achieved. This favorable performance mainly resulted from the combined effect of the high-dielectric-constant gate dielectric and the TiO2-InGaZnO active semiconductor bilayer, which reduced the operating voltage, enhanced the device mobility, and improved the transistor gate swing. This TiO2-InGaZnO TFT exhibits great potential for future high-speed and high-resolution display applications. (C) 2014 Elsevier Ltd. All rights reserved.
Amorphous Titanium Oxide Semiconductors on Quasi-Crystal-Like InGaZnO Channels for Thin Film Transistor Applications
(2015-06)
Hsu, Hsiao-Hsuan
;
Chiou, Ping
;
Cheng, Chun-Hu
;
Yen, Shiang-Shiou
;
Tung, Chien-Hung
This paper reports an InGaZnO thin-film transistor with titanium-oxide semiconductor as channel capping layer. Based on the experimental results, the titanium-oxide semiconductor has the function of not only a surface passivation layer to reduce the defect states localized at grain boundaries near source/drain contacts, but also a mobility booster to enhance electric field across channel. Compared to control IGZO TFT, the crystalline IGZO TFTs with titanium-oxide semiconductor exhibits an improved performance of a low drive voltage of <5 V, a low threshold voltage of 1.9 V, a low sub-threshold swing of 244 mV/decade, and a high mobility of 13.7 cm(2)/V s. The simple titanium-oxide capping process have been demonstrated in this work, which provides considerable potential for further display applications requiring a low power operation and a low-temperature fabrication.
An Oxygen Gettering Scheme for Improving Device Mobility and Subthreshold Swing of InGaZnO-Based Thin-Film Transistor
(2014-09-01)
Hsu, Hsiao-Hsuan
;
Chang, Chun-Yen
;
Cheng, Chun-Hu
;
Chiou, Shan-Haw
;
Huang, Chiung-Hui
This study involved developing a low-power and high-mobility metal-oxide thin-film transistor that incorporated a bilayer IGZO/IGZO:Ti semiconductor material. Compared with control metal-oxide TFTs, the bilayer IGZO TFT through thickness modulation of IGZO: Ti can reach the smallest subthreshold swing (85 mV/decade) and the highest field effect mobility (49 cm(2)/Vs) at a drive voltage of <3 V. This performance level improvement can be attributed to the gettering effect caused by the IGZO: Ti capping layer and its dual advantages, which enhance device mobility and improve gate swing.
Bipolar Conduction in Tin-Oxide Semiconductor Channel Treated by Oxygen Plasma for Low-Power Thin-Film Transistor Application
(2016-03)
Chen, Po-Chun
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Wu, Yung-Hsien
;
Zheng, Zhi-Wei
;
Chiu, Yu-Chien
;
Cheng, Chun-Hu
In this paper, we investigated the bipolar conduction mechanism in thin-film transistors (TFTs) with oxygen plasma treatment on tin-oxide channel. The optimized p-type thin-oxide TFTs showed an on/off ratio of >10(4), a threshold voltage of -1.05 V, and a field-effect mobility of 2.14 cm(2).V-1.s(-1). By increasing the exposure time of oxygen plasma, excess oxygen was incorporated to thin-oxide channel and converted thin monoxide to oxygen-rich n-type thin dioxide, which in turn led to n-type operation. It indicated that oxygen plasma was the critical factor to determine oxygen concentration, oxygen vacancies, metal ions and channel polarity. This proposed oxygen-content tuning through plasma treatment approach shows great promise in simplification of TFT process that can achieve n-type and p-type TFTs under the same device process.
Characteristic Simulation of Hybrid Multilayer Junctionless Field Effect Transistors with Negative Capacitance Effect
(2020-01-01)
Ma, Jun
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Liu, Chien
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Liu, Wei-Dong
;
Hung, Yu-Wen
;
Fan, Yu-Chi
In this study, we reported a hybrid multi-PNPN channel junctionless field effect transistor (JLFET) with negative capacitance (NC) effect by simulation. By incorporating a ferroelectric HfAlO capacitor with NC effect, an extremely low subthreshold swing of 34 mVdecade, a very high onoff current ratio and a very low driven voltage were achieved in the NC-enhanced hybrid multi-PNPN channel JLFET. This novel device not only improves the on-state current reduction while channel scaling down, but also shows great potential for the next-generation low-power three-dimensional stacked integrated circuit applications.
Correlation of thermal annealing effect, crystallinity and electrical characteristics in c-axis crystallized InGaZnO thin-film transistors
(2015-09-15)
Hsu, Hsiao-Hsuan
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Yen, Shiang-Shiou
;
Chiu, Yu-Chien
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Chiou, Ping
;
Chang, Chun-Yen
A low off-state current of 1.6 x 10(-14) A/mu m and a small subthreshold gate swing of 152 mV/decade were achieved in a novel thin film transistor using a c-axis crystallized InGaZnO semiconductor that could be obtained at a low substrate temperature range of 150 degrees C. From experimental results, we found that the lowered off-state current is mainly attributed to the formation of rich Ga-O bonds to reduce oxygen vacancies, and the c-axis crystallized structure of IGZO to increase the potential barrier on the source side due to the increase of local trap states at the grain boundary. (C) 2015 Elsevier B.V. All rights reserved.
Crystallized Ohmic Contact Effect in AlGaN/GaN High Electron Mobility Transistor
(2013-08-01)
Liao, Sheng Yu
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Chang, Tsu
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Hsu, Hsiao-Hsuan
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Cheng, Chun-Hu
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Chang, Liann-Be
In this study, we investigate the grain size effect of high electron mobility transistor devices with ohmic contact metals of stacked Ti/Al/Ni/Au and Ti/Al/Mo/Au. In addition to a comparison of electrical characteristics, the ohmic contacts were also examined by a scratch test for the observation of adhesion behavior. The experimental results demonstrate that the metal grain size is strongly dependent on metal adhesion, which may lead to bonding issues. Moreover, the grain-induced lateral stress lowers the drive current and increases the off-state current owing to the degraded gate swing and transconductance of transistor switching characteristics. (C) 2013 The Japan Society of Applied Physics
Fast Low-Temperature Plasma Process for the Application of Flexible Tin-Oxide-Channel Thin Film Transistors
(2017-09-01)
Chen, Po-Chun
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Chiu, Yu-Chien
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Zheng, Zhi-Wei
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Lin, Ming-Huei
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Cheng, Chun-Hu
In this study, we demonstrated a p-type and n-type SnO TFTs on flexible polyimide substrate. The fabricated p-type SnO TFT showed a high I-on/I-off of 5.7 x 10(5) and a high mu(FE) of 10.7 cm(2) V-1 s(-1). Through optimizing the oxygen plasma condition, the n-type channel TFT transfered from prime p-type channel exhibits excellent characteristics, including a high on/off current ratio of 6.6 x 10(3), a low threshold voltage of -0.13 V, and a very high field-effect mobility of 28 cm(2) V-1 s(-1). This proposed low-temperature oxygen plasma treatment shows the potential in simplification of TFT process that can achieve n-type and p-type TFTs under the same device process.
Ferroelectric Characterization of Hafnium-Oxide-Based Ferroelectric Memories with Remote Nitrogen Plasma Treatments
(2019-01-01)
Lee, You-Ting
;
Chen, Hsuan-Han
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Tung, Yi-Chun
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Shih, Bing-Yang
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Hsiung, Szu-Yen
In this paper, we experimentally demonstrated the advantage of remote nitrogen plasma on improving interface quality of HfO2-based ferroelectric devices. The remote nitrogen plasma not only reduces leakage current of gate stack to appropriately sustain the ferroelectricity during ferroelectric domain switching, but also effectively improve the ferroelectric fatigue to enhance endurance cycling performance.
Flexible InGaZnO TFTs with Stacked GeO2/TiO2 Gate Dielectrics
(2013)
Hsu, Hsiao-Hsuan
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Chang, Chun-Yen
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Cheng, Chun-Hu
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Yu, Shu-Hung
;
Su, Ching-Yuan
We reported an amorphous InGaZnO thin-film transistor using stacked gate dielectrics of GeO2/TiO2 on flexible polycarbonate substrate. The flexible TFT showed a low threshold voltage of 2.2 V, small sub-threshold swing of 256 mV/decade, an field effect mobility of 4 cm(2)/Vs, and a good I-on/I-off ratio of 3.7x10(5). The flexible TFT with low operation voltage and high drive current could be attributed to the combined effect of flat plastic substrate, large band-gap GeO2 and higher-kappa TiO2.
Flexible InGaZnO thin film transistors using stacked Y2O3/TiO2/Y2O3 gate dielectrics grown at room temperature
(2013-04-01)
Hsu, Hsiao-Hsuan
;
Chang, Chun-Yen
;
Cheng, Chun-Hu
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
In this Letter, we report a low operation voltage and high mobility flexible InGaZnO thin-film transistor (TFT) using room-temperature processed Y2O3/TiO2/Y2O3 gate dielectric. The flexible IGZO TFT showed a low threshold voltage of 0.75 V, a small sub-threshold swing of 137 mV/decade, a good field effect mobility of 32.7 cm(2)/V s, and a large I-on/I-off ratio of 1.7 x 10(6). The low operation voltage, small subthreshold swing and high mobility could be ascribed to the combination of high-kappa TiO2 and large band gap Y2O3, which provide the potential to meet the requirements of low-temperature and low-power portable electronics. (C) 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Forming-Free SiGeOx/TiOy Resistive Random Access Memories Featuring Large Current Distribution Windows
(2019-12-01)
Cheng, Chun-Hu
;
Chin, Albert
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Hsu, Hsiao-Hsuan
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Optimal device integrity was achieved in Ni/SiGeOx/TiOy/TaN resistive memory by using a formingfree switch with a low switching power of 790 mu W, stable endurance of 10(4) cycles, optimal retention time of 10(5) s, resistance window of at least 1150x, and tight current distributions at 85 degrees C. These characteristics are attributed to the low current switching obtained using SiGeOx with a high oxygen vacancy density and highly defective TiOy grain boundaries.
Fully room-temperature IGZO thin film transistors adopting stacked gate dielectrics on flexible polycarbonate substrate
(2013-11-01)
Hsu, Hsiao-Hsuan
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Chang, Chun-Yen
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Cheng, Chun-Hu
;
Yu, Shu-Hung
;
Su, Ching-Yuan
This study demonstrates the feasibility of producing an InGaZnO thin-film transistor (TFT) using a high-kappa germanium oxide (GeO2)/titanium oxide (TiO2)/GeO2 gate stack on a flexible polycarbonate substrate. The flexible TFT exhibited a small sub-threshold swing of 0.132 V/decade, an acceptable field effect mobility of 8 cm(2)/(V s), and a robust I-on/I-off ratio of 2.4 x 10(7). The improved device performance can be attributed to the combined effect of high-kappa TiO2 and the large band gap of GeO2 that exhibits a tendency to remain in a Ge4+ oxidation state at room temperature. (C) 2013 Elsevier Ltd. All rights reserved.
Gamma-Ray Irradiation Effect on Ferroelectric Devices with Hafnium Aluminum Oxides
(2019-12-01)
Liu, Chien
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Tung, Yi-Chun
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Wu, Tian-Li
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Cheng, Chun-Hu
;
Tseng, Chih-Yang
Herein, the gamma-ray irradiation effect on ferroelectric HfAlO(x)capacitors for biomedical and space applications is investigated. The experimental results focus on the observation of ferroelectric polarization characteristics in support of different defect mechanisms induced by annealing, endurance cycling, and gamma-ray irradiation. It is found that the HfAlO(x)with low Al doping of 6.5% become more vulnerable to radiation exposure, but a remarkable improvement in 9%-Al-doped HfAlO(x)due to less oxygen vacancies is demonstrated. In addition, the results also confirm that the fatigue property of ferroelectric HfAlO(x)capacitor is determined by the electric-stress-induced defect during endurance cycling, not mainly contributed by irradiation damage, which shows the potential for memory applications in rigorous irradiation environment.
Gettering Effect Induced by Oxygen-Deficient Titanium Oxide in InZnO and InGaZnO Channel Systems for Low-Power Display Applications
(2016-03)
Yen, Shiang-Shiou
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Chiu, Yu-Chien
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Cheng, Chun-Hu
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Chen, Po-Chun
;
Yeh, Yu-Chen
This paper reported the IGZO and IZO thin-film transistor (TFT) with titanium-oxide semiconductor as channel capping layer. After the TiOx Gettering process, the oxygen vacancies in IGZO channel were successfully modified to maximize the carrier concentration and device mobility. The superior transfer characteristics included a low sub-threshold swing of 79 mV/decade, a very high mobility of 68 cm(2)/V.s, and good on/off-current ratio of 5.61 x 10(6). However, the IZO channel with nano-crystallized grains and without Ga atom doping showed unfavorable transistor characteristics. In addition to apparently degraded transfer properties, the spontaneously oxidized TiOx capping layer also lead to an increase of channel parasitic resistance that limits the output driving current. Therefore, we believe that the existence of Ga-O bonds among IGZO channel would be helpful to stabilize oxygen diffusion behavior and electric structure during Gettering process.
High holding voltage segmentation stacking silicon-controlled-rectifier structure with field implant as body ties blocking layer
(2016-04)
Yen, Shiang-Shiou
;
Cheng, Chun-Hu
;
Lan, Yu-Pin
;
Chiu, Yu-Chien
;
Fan, Chia-Chi
High electrostatic discharge (ESD) protection robustness and good transient-induced latchup immunity are two important issues for high voltage integrate circuit application. In this study, we report a high-voltage-n-type-field (HVNF) implantation to act as the body ties blocking layer in segmented topology silicon-controlled-rectifier (SCR) structure in 0.11 mu m 32 V high voltage process. This body ties blocking layer eliminate the elevated triggered voltage in segmented technique. Using a large resistance as shunt resistor in resistor assisted triggered SCRs stacking structure, the double snapback phenomenon is eliminate. The series SCR could be decoupled a sufficient voltage drop to turned-on when a very low current flow through the shunt resistor. The holding voltage and the failure current of 22 V and 3.4 A are achieved in the best condition of segmented topology SCR stacking structure, respectively. It improves the latchup immunity at high voltage ICs application. On the other hand, the triggered voltage almost keep the same value which is identical to SCR single cell without using segmented topology. (C) 2016 The Japan Society of Applied Physics
High holding voltage segmentation stacking silicon-controlled-rectifier structure with field implant as body ties blocking layer
(2016-04-01)
Yen, Shiang-Shiou
;
Cheng, Chun-Hu
;
Lan, Yu-Pin
;
Chiu, Yu-Chien
;
Fan, Chia-Chi
High electrostatic discharge (ESD) protection robustness and good transient-induced latchup immunity are two important issues for high voltage integrate circuit application. In this study, we report a high-voltage-n-type-field (HVNF) implantation to act as the body ties blocking layer in segmented topology silicon-controlled-rectifier (SCR) structure in 0.11 mu m 32 V high voltage process. This body ties blocking layer eliminate the elevated triggered voltage in segmented technique. Using a large resistance as shunt resistor in resistor assisted triggered SCRs stacking structure, the double snapback phenomenon is eliminate. The series SCR could be decoupled a sufficient voltage drop to turned-on when a very low current flow through the shunt resistor. The holding voltage and the failure current of 22 V and 3.4 A are achieved in the best condition of segmented topology SCR stacking structure, respectively. It improves the latchup immunity at high voltage ICs application. On the other hand, the triggered voltage almost keep the same value which is identical to SCR single cell without using segmented topology. (C) 2016 The Japan Society of Applied Physics
High Mobility Bilayer Metal-Oxide Thin Film Transistors Using Titanium-Doped InGaZnO
(2014-01-01)
Hsu, Hsiao-Hsuan
;
Chang, Chun-Yen
;
Cheng, Chun-Hu
;
Chiou, Shan-Haw
;
Huang, Chiung-Hui
We report a high performance indium-gallium-zinc oxide (IGZO)/IGZO:Ti bilayer metal-oxide thin-film transistor (TFT) with a low drive voltage of <2 V. Compared with conventional IGZO TFTs, the novel bilayer metal-oxide TFTs through IGZO thickness modulation can reach the lowest off current of 1.6 x 10(-11) A, smallest sub-threshold swing of 73 mV/decade, and highest mobility of 63 cm(2)/Vs, which may create the potential application for high resolution display.