1
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Huang H, Peng C, Xu M, Chen L, Li X. Dependence of a Hydrogen Buffer Layer on the Properties of Top-Gate IGZO TFT. MICROMACHINES 2024; 15:722. [PMID: 38930691 PMCID: PMC11205436 DOI: 10.3390/mi15060722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2024] [Revised: 05/28/2024] [Accepted: 05/28/2024] [Indexed: 06/28/2024]
Abstract
In this paper, the effect of a buffer layer created using different hydrogen-containing ratios of reactive gas on the electrical properties of a top-gate In-Ga-Zn-O thin-film transistor was thoroughly investigated. The interface roughness between the buffer layer and active layer was characterized using atomic force microscopy and X-ray reflection. The results obtained using Fourier transform infrared spectroscopy show that the hydrogen content of the buffer layer increases with the increase in the hydrogen content of the reaction gas. With the increase in the hydrogen-containing materials in the reactive gas, field effect mobility and negative bias illumination stress stability improve nearly twofold. The reasons for these results are explained using technical computer-aided design simulations.
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Affiliation(s)
- Huixue Huang
- Shanghai Collaborative Innovation Center of Intelligent Sensing Chip Technology, Shanghai University, Shanghai 201800, China; (H.H.); (M.X.)
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, Shanghai 200072, China;
| | - Cong Peng
- Shanghai Collaborative Innovation Center of Intelligent Sensing Chip Technology, Shanghai University, Shanghai 201800, China; (H.H.); (M.X.)
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, Shanghai 200072, China;
| | - Meng Xu
- Shanghai Collaborative Innovation Center of Intelligent Sensing Chip Technology, Shanghai University, Shanghai 201800, China; (H.H.); (M.X.)
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, Shanghai 200072, China;
| | - Longlong Chen
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, Shanghai 200072, China;
| | - Xifeng Li
- Shanghai Collaborative Innovation Center of Intelligent Sensing Chip Technology, Shanghai University, Shanghai 201800, China; (H.H.); (M.X.)
- Key Laboratory of Advanced Display and System Applications of Ministry of Education, Shanghai University, Shanghai 200072, China;
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2
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Du H, Tuokedaerhan K, Zhang R. Electrical performance of La-doped In 2O 3 thin-film transistors prepared using a solution method for low-voltage driving. RSC Adv 2024; 14:15483-15490. [PMID: 38807708 PMCID: PMC11132053 DOI: 10.1039/d4ra01409j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 05/09/2024] [Indexed: 05/30/2024] Open
Abstract
In this paper, La-doped In2O3 thin-film transistors (TFTs) were prepared by using a solution method, and the effects of La doping on the structure, surface morphology, optics, and performance of In2O3 thin films and TFTs were systematically investigated. The oxygen defects concentration decreased from 27.54% to 17.93% when La doping was increased to 10 mol%, and La served as a carrier suppressor, effectively passivating defects such as oxygen defects. In fact, the trap density at the dielectric/channel interface and within the active layer can be effectively reduced using this approach. With the increase of La concentration, the mobility of LaInO TFTs decreases gradually; the threshold voltage is shifted in the positive direction, and the TFT devices are operated in the enhanced mode. The TFT device achieved a subthreshold swing (SS) as low as 0.84 V dec-1, a mobility (μ) of 14.22 cm2 V-1 s-1, a threshold voltage (VTH) of 2.16 V, and a current switching ratio of Ion/Ioff of 105 at a low operating voltage of 1 V. Therefore, regulating the doping concentration of La can greatly enhance the performance of TFT devices, which promotes the application of such devices in high-performance, large-scale, and low-power electronic systems.
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Affiliation(s)
- Hongguo Du
- Xinjiang Key Laboratory of Solid State Physics and Devices, Xinjiang University Urumqi 830046 China
- The School of Physics Science and Technology, Xinjiang University Urumqi 830046 China
| | - Kamale Tuokedaerhan
- Xinjiang Key Laboratory of Solid State Physics and Devices, Xinjiang University Urumqi 830046 China
- The School of Physics Science and Technology, Xinjiang University Urumqi 830046 China
| | - Renjia Zhang
- Xinjiang Key Laboratory of Solid State Physics and Devices, Xinjiang University Urumqi 830046 China
- The School of Physics Science and Technology, Xinjiang University Urumqi 830046 China
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3
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Sun B, Huang H, Wen P, Xu M, Peng C, Chen L, Li X, Zhang J. Research Progress of Vertical Channel Thin Film Transistor Device. SENSORS (BASEL, SWITZERLAND) 2023; 23:6623. [PMID: 37514918 PMCID: PMC10383718 DOI: 10.3390/s23146623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 07/12/2023] [Accepted: 07/17/2023] [Indexed: 07/30/2023]
Abstract
Thin film transistors (TFTs) as the core devices for displays, are widely used in various fields including ultra-high-resolution displays, flexible displays, wearable electronic skins and memory devices, especially in terms of sensors. TFTs have now started to move towards miniaturization. Similarly to MOSFETs problem, traditional planar structure TFTs have difficulty in reducing the channel's length sub-1μm under the existing photolithography technology. Vertical channel thin film transistors (V-TFTs) are proposed. It is an effective solution to overcome the miniaturization limit of traditional planar TFTs. So, we summarize the different aspects of VTFTs. Firstly, this paper introduces the structure types, key parameters, and the impact of different preparation methods in devices of V-TFTs. Secondly, an overview of the research progress of V-TFTs' active layer materials in recent years, the characteristics of V-TFTs and their application in examples has proved the enormous application potential of V-TFT in sensing. Finally, in addition to the advantages of V-TFTs, the current technical challenge and their potential solutions are put forward, and the future development trend of this new structure of V-TFTs is proposed.
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Affiliation(s)
- Benxiao Sun
- School of Microelectronics, Shanghai University, Shanghai 201800, China
- Key Laboratory of Advanced Display and System Applications, Ministry of Education, Shanghai University, Shanghai 200072, China
| | - Huixue Huang
- School of Microelectronics, Shanghai University, Shanghai 201800, China
- Key Laboratory of Advanced Display and System Applications, Ministry of Education, Shanghai University, Shanghai 200072, China
| | - Pan Wen
- School of Microelectronics, Shanghai University, Shanghai 201800, China
- Key Laboratory of Advanced Display and System Applications, Ministry of Education, Shanghai University, Shanghai 200072, China
| | - Meng Xu
- Key Laboratory of Advanced Display and System Applications, Ministry of Education, Shanghai University, Shanghai 200072, China
| | - Cong Peng
- Key Laboratory of Advanced Display and System Applications, Ministry of Education, Shanghai University, Shanghai 200072, China
| | - Longlong Chen
- Key Laboratory of Advanced Display and System Applications, Ministry of Education, Shanghai University, Shanghai 200072, China
| | - Xifeng Li
- Key Laboratory of Advanced Display and System Applications, Ministry of Education, Shanghai University, Shanghai 200072, China
| | - Jianhua Zhang
- Key Laboratory of Advanced Display and System Applications, Ministry of Education, Shanghai University, Shanghai 200072, China
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4
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Wu CH, Mohanty SK, Huang BW, Chang KM, Wang SJ, Ma KJ. High-mobility and low subthreshold swing amorphous InGaZnO thin-film transistors by in situH 2plasma and neutral oxygen beam irradiation treatment. NANOTECHNOLOGY 2023; 34:175202. [PMID: 36696686 DOI: 10.1088/1361-6528/acb5f9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 01/25/2023] [Indexed: 06/17/2023]
Abstract
In this work, staggered bottom-gate structure amorphous In-Ga-Zn-O (a-IGZO) thin film transistors (TFTs) with high-k ZrO2gate dielectric were fabricated using low-cost atmospheric pressure-plasma enhanced chemical vapor deposition (AP-PECVD) within situhydrogenation to modulate the carrier concentration and improve interface quality. Subsequently, a neutral oxygen beam irradiation (NOBI) technique is applied, demonstrating that a suitable NOBI treatment could successfully enhance electrical characteristics by reducing native defect states and minimize the trap density in the back channel. A reverse retrograde channel (RRGC) with ultra-high/low carrier concentration is also formed to prevent undesired off-state leakage current and achieve a very low subthreshold swing. The resulting a-IGZO TFTs exhibit excellent electrical characteristics, including a low subthreshold swing of 72 mV dec-1and high field-effect mobility of 35 cm2V-1s-1, due to conduction path passivation and stronger carrier confinement in the RRGC. The UV-vis spectroscopy shows optical transmittance above 90% in the visible range of the electromagnetic spectrum. The study confirms the H2plasma with NOBI-treated a-IGZO/ZrO2TFT is a promising candidate for transparent electronic device applications.
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Affiliation(s)
- Chien-Hung Wu
- Department of Optoelectronics & Materials Engineering, Chung Hua University, Hsinchu, 30010, Taiwan, ROC
| | - Srikant Kumar Mohanty
- UST-IPPP, College of Electrical and Computer Engineering, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan, ROC
| | - Bo-Wen Huang
- Institute of Electronics, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan, ROC
| | - Kow-Ming Chang
- Institute of Electronics, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan, ROC
| | - Shui-Jinn Wang
- Department of Electrical Engineering, National Cheng Kung University, Tainan, Taiwan, ROC
| | - Kung-Jeng Ma
- Department of Optoelectronics & Materials Engineering, Chung Hua University, Hsinchu, 30010, Taiwan, ROC
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Wang C, Li Y, Jin Y, Guo G, Song Y, Huang H, He H, Wang A. One-Step Synergistic Treatment Approach for High Performance Amorphous InGaZnO Thin-Film Transistors Fabricated at Room Temperature. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:3481. [PMID: 36234608 PMCID: PMC9565279 DOI: 10.3390/nano12193481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 09/28/2022] [Accepted: 10/03/2022] [Indexed: 06/16/2023]
Abstract
Amorphous InGaZnO (a-InGaZnO) is currently the most prominent oxide semiconductor complement to low-temperature polysilicon for thin-film transistor (TFT) applications in next-generation displays. However, balancing the transmission performance and low-temperature deposition is the primary obstacle in the application of a-InGaZnO TFTs in the field of ultra-high resolution optoelectronic display. Here, we report that a-InGaZnO:O TFT prepared at room temperature has high transport performance, manipulating oxygen vacancy (VO) defects through an oxygen-doped a-InGaZnO framework. The main electrical properties of a-InGaZnO:O TFTs included high field-effect mobility (µFE) of 28 cm2/V s, a threshold voltage (Vth) of 0.9 V, a subthreshold swing (SS) of 0.9 V/dec, and a current switching ratio (Ion/Ioff) of 107; significant improvements over a-InGaZnO TFTs without oxygen plasma. A possible reason for this is that appropriate oxygen plasma treatment and room temperature preparation technology jointly play a role in improving the electrical performance of a-InGaZnO TFTs, which could not only increase carrier concentration, but also reduce the channel-layer surface defects and interface trap density of a-InGaZnO TFTs. These provides a powerful way to synergistically boost the transport performance of oxide TFTs fabricated at room temperature.
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Affiliation(s)
- Chunlan Wang
- School of Science, Xi’an Polytechnic University, Xi’an 710048, China
| | - Yuqing Li
- School of Science, Xi’an Polytechnic University, Xi’an 710048, China
| | - Yebo Jin
- School of Science, Xi’an Polytechnic University, Xi’an 710048, China
| | - Gangying Guo
- School of Science, Xi’an Polytechnic University, Xi’an 710048, China
| | - Yongle Song
- School of Science, Xi’an Polytechnic University, Xi’an 710048, China
| | - Hao Huang
- Guangxi Key Laboratory of Processing for Nonferrous Metals and Featured Material, School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China
| | - Han He
- Guangxi Key Laboratory of Processing for Nonferrous Metals and Featured Material, School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China
| | - Aolin Wang
- Guangxi Key Laboratory of Processing for Nonferrous Metals and Featured Material, School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China
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6
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Bae SH, Yang JH, Kim YH, Kwon YH, Seong NJ, Choi KJ, Hwang CS, Yoon SM. Roles of Oxygen Interstitial Defects in Atomic-Layer Deposited InGaZnO Thin Films with Controlling the Cationic Compositions and Gate-Stack Processes for the Devices with Subμm Channel Lengths. ACS APPLIED MATERIALS & INTERFACES 2022; 14:31010-31023. [PMID: 35785988 DOI: 10.1021/acsami.2c07258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Roles of oxygen interstitial defects located in the In-Ga-Zn-O (IGZO) thin films prepared by atomic layer deposition were investigated with controlling the cationic compositions and gate-stack process conditions. It was found from the spectroscopic ellipsometry analysis that the excess oxygens increased with increasing the In contents within the IGZO channels. While the device using the IGZO channel with an In/Ga ratio of 0.2 did not show marked differences with the variations in the oxidant types during the gate-stack formation, the device characteristics were severely deteriorated with increasing the In/Ga ratio to 1.4, when the Al2O3 gate insulator (GI) was prepared with the H2O oxidants (H2O-Al2O3) due to a higher amount of excess oxygen in the channel. Additionally, during the deposition process of the Al-doped ZnO (AZO) gate electrode (GE) replacing from the indium-tin oxide (ITO) GE, the thermal annealing effect at 180 °C facilitated the passivation of oxygen vacancy and the strengthening of metal-oxygen bonding, which could stabilize the TFT operations. From these results, the gate-stack structure employing O3-processed Al2O3 GI (O3-Al2O3) and AZO GE (OA) was suggested to be most suitable for the device using IGZO channel with a higher In content. On the other hand, the device employing H2O-Al2O3 GI and AZO GE exhibited larger negative shifts of threshold voltage (VTH) under positive-bias-temperature stress (PBTS) condition than the device employing O3- Al2O3 GI and ITO GE due to larger hydrogen contents within the gate stacks. Anomalous negative shifts of VTH were accelerated with increasing the In contents of the IGZO channel. When the channel length of the fabricated device were scaled down to submicrometer regime, the OA gate stacks successfully alleviated the short-channel effects.
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Affiliation(s)
- Soo-Hyun Bae
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin, Gyeonggi-do 17104, Korea
| | - Jong-Heon Yang
- ICT Creative Research Laboratory, Electronics and Telecommunications Research Institute, Daejeon 34129, Korea
| | - Yong-Hae Kim
- ICT Creative Research Laboratory, Electronics and Telecommunications Research Institute, Daejeon 34129, Korea
| | | | | | | | - Chi-Sun Hwang
- ICT Creative Research Laboratory, Electronics and Telecommunications Research Institute, Daejeon 34129, Korea
| | - Sung-Min Yoon
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, Yongin, Gyeonggi-do 17104, Korea
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7
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Wang Y, Zhou Y, Xia Z, Zhou W, Zhang M, Yeung FSY, Wong M, Kwok HS, Zhang S, Lu L. Compact Integration of Hydrogen–Resistant a–InGaZnO and Poly–Si Thin–Film Transistors. MICROMACHINES 2022; 13:mi13060839. [PMID: 35744453 PMCID: PMC9227547 DOI: 10.3390/mi13060839] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 05/17/2022] [Accepted: 05/21/2022] [Indexed: 11/16/2022]
Abstract
The low–temperature poly–Si oxide (LTPO) backplane is realized by monolithically integrating low–temperature poly–Si (LTPS) and amorphous oxide semiconductor (AOS) thin–film transistors (TFTs) in the same display backplane. The LTPO–enabled dynamic refreshing rate can significantly reduce the display’s power consumption. However, the essential hydrogenation of LTPS would seriously deteriorate AOS TFTs by increasing the population of channel defects and carriers. Hydrogen (H) diffusion barriers were comparatively investigated to reduce the H content in amorphous indium–gallium–zinc oxide (a–IGZO). Moreover, the intrinsic H–resistance of a–IGZO was impressively enhanced by plasma treatments, such as fluorine and nitrous oxide. Enabled by the suppressed H conflict, a novel AOS/LTPS integration structure was tested by directly stacking the H–resistant a–IGZO on poly–Si TFT, dubbed metal–oxide–on–Si (MOOS). The noticeably shrunken layout footprint could support much higher resolution and pixel density for next–generation displays, especially AR and VR displays. Compared to the conventional LTPO circuits, the more compact MOOS circuits exhibited similar characteristics.
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Affiliation(s)
- Yunping Wang
- School of Electronic and Computer Engineering, Peking University, Shenzhen 518055, China; (Y.W.); (Y.Z.); (S.Z.)
| | - Yuheng Zhou
- School of Electronic and Computer Engineering, Peking University, Shenzhen 518055, China; (Y.W.); (Y.Z.); (S.Z.)
| | - Zhihe Xia
- State Key Laboratory of Advanced Displays and Optoelectronics and Technologies, Department of Electronic & Computer Engineering, The Hong Kong University of Science and Technology, Hong Kong 999077, China; (Z.X.); (W.Z.); (F.S.Y.Y.); (M.W.); (H.S.K.)
| | - Wei Zhou
- State Key Laboratory of Advanced Displays and Optoelectronics and Technologies, Department of Electronic & Computer Engineering, The Hong Kong University of Science and Technology, Hong Kong 999077, China; (Z.X.); (W.Z.); (F.S.Y.Y.); (M.W.); (H.S.K.)
| | - Meng Zhang
- College of Electronic and Information Engineering, Shenzhen University, Shenzhen 518060, China;
| | - Fion Sze Yan Yeung
- State Key Laboratory of Advanced Displays and Optoelectronics and Technologies, Department of Electronic & Computer Engineering, The Hong Kong University of Science and Technology, Hong Kong 999077, China; (Z.X.); (W.Z.); (F.S.Y.Y.); (M.W.); (H.S.K.)
| | - Man Wong
- State Key Laboratory of Advanced Displays and Optoelectronics and Technologies, Department of Electronic & Computer Engineering, The Hong Kong University of Science and Technology, Hong Kong 999077, China; (Z.X.); (W.Z.); (F.S.Y.Y.); (M.W.); (H.S.K.)
| | - Hoi Sing Kwok
- State Key Laboratory of Advanced Displays and Optoelectronics and Technologies, Department of Electronic & Computer Engineering, The Hong Kong University of Science and Technology, Hong Kong 999077, China; (Z.X.); (W.Z.); (F.S.Y.Y.); (M.W.); (H.S.K.)
| | - Shengdong Zhang
- School of Electronic and Computer Engineering, Peking University, Shenzhen 518055, China; (Y.W.); (Y.Z.); (S.Z.)
| | - Lei Lu
- School of Electronic and Computer Engineering, Peking University, Shenzhen 518055, China; (Y.W.); (Y.Z.); (S.Z.)
- Correspondence:
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8
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Zhu Z, Cao W, Huang X, Shi Z, Zhou D, Xu W. Analysis of Nitrogen-Doping Effect on Sub-Gap Density of States in a-IGZO TFTs by TCAD Simulation. MICROMACHINES 2022; 13:mi13040617. [PMID: 35457921 PMCID: PMC9032452 DOI: 10.3390/mi13040617] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 04/08/2022] [Accepted: 04/12/2022] [Indexed: 11/16/2022]
Abstract
In this work, the impact of nitrogen doping (N-doping) on the distribution of sub-gap states in amorphous InGaZnO (a-IGZO) thin-film transistors (TFTs) is qualitatively analyzed by technology computer-aided design (TCAD) simulation. According to the experimental characteristics, the numerical simulation results reveal that the interface trap states, bulk tail states, and deep-level sub-gap defect states originating from oxygen-vacancy- (Vo) related defects can be suppressed by an appropriate amount of N dopant. Correspondingly, the electrical properties and reliability of the a-IGZO TFTs are dramatically enhanced. In contrast, it is observed that the interfacial and deep-level sub-gap defects are increased when the a-IGZO TFT is doped with excess nitrogen, which results in the degeneration of the device’s performance and reliability. Moreover, it is found that tail-distributed acceptor-like N-related defects have been induced by excess N-doping, which is supported by the additional subthreshold slope degradation in the a-IGZO TFT.
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Affiliation(s)
- Zheng Zhu
- College of Integrated Circuit Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China; (Z.Z.); (W.C.)
| | - Wei Cao
- College of Integrated Circuit Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China; (Z.Z.); (W.C.)
| | - Xiaoming Huang
- College of Integrated Circuit Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China; (Z.Z.); (W.C.)
- Correspondence:
| | - Zheng Shi
- School of Communications and Information Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China;
| | - Dong Zhou
- National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, China; (D.Z.); (W.X.)
| | - Weizong Xu
- National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, China; (D.Z.); (W.X.)
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9
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Liu WS, Hsu CH, Jiang Y, Lai YC, Kuo HC. Improving Device Characteristics of Dual-Gate IGZO Thin-Film Transistors with Ar-O 2 Mixed Plasma Treatment and Rapid Thermal Annealing. MEMBRANES 2021; 12:49. [PMID: 35054574 PMCID: PMC8780293 DOI: 10.3390/membranes12010049] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 12/24/2021] [Accepted: 12/26/2021] [Indexed: 12/02/2022]
Abstract
In this study, high-performance indium-gallium-zinc oxide thin-film transistors (IGZO TFTs) with a dual-gate (DG) structure were manufactured using plasma treatment and rapid thermal annealing (RTA). Atomic force microscopy measurements showed that the surface roughness decreased upon increasing the O2 ratio from 16% to 33% in the argon-oxygen plasma treatment mixture. Hall measurement results showed that both the thin-film resistivity and carrier Hall mobility of the Ar-O2 plasma-treated IGZO thin films increased with the reduction of the carrier concentration caused by the decrease in the oxygen vacancy density; this was also verified using X-ray photoelectron spectroscopy measurements. IGZO thin films treated with Ar-O2 plasma were used as channel layers for fabricating DG TFT devices. These DG IGZO TFT devices were subjected to RTA at 100 °C-300 °C for improving the device characteristics; the field-effect mobility, subthreshold swing, and ION/IOFF current ratio of the 33% O2 plasma-treated DG TFT devices improved to 58.8 cm2/V·s, 0.12 V/decade, and 5.46 × 108, respectively. Long-term device stability reliability tests of the DG IGZO TFTs revealed that the threshold voltage was highly stable.
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Affiliation(s)
- Wei-Sheng Liu
- Department of Electrical Engineering, Yuan Ze University, Chung-Li 320, Taiwan; (C.-H.H.); (Y.J.); (Y.-C.L.)
| | - Chih-Hao Hsu
- Department of Electrical Engineering, Yuan Ze University, Chung-Li 320, Taiwan; (C.-H.H.); (Y.J.); (Y.-C.L.)
| | - Yu Jiang
- Department of Electrical Engineering, Yuan Ze University, Chung-Li 320, Taiwan; (C.-H.H.); (Y.J.); (Y.-C.L.)
| | - Yi-Chun Lai
- Department of Electrical Engineering, Yuan Ze University, Chung-Li 320, Taiwan; (C.-H.H.); (Y.J.); (Y.-C.L.)
| | - Hsing-Chun Kuo
- Department of Nursing, Division of Basic Medical Sciences, Chang Gung University of Science and Technology, Chiayi 613, Taiwan
- Chang Gung Memorial Hospital, Chiayi 613, Taiwan
- Research Center for Food and Cosmetic Safety, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan 333, Taiwan
- Chronic Diseases and Health Promotion Research Center, Chang Gung University of Science and Technology, Chiayi 613, Taiwan
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10
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Prasad OK, Mohanty SK, Wu CH, Yu TY, Chang KM. Role of in-situhydrogen plasma treatment on gate bias stability and performance of a-IGZO thin-film transistors. NANOTECHNOLOGY 2021; 32:395203. [PMID: 34144544 DOI: 10.1088/1361-6528/ac0cb0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 06/18/2021] [Indexed: 06/12/2023]
Abstract
This work investigates the effect of anin situhydrogen plasma treatment on gate bias stability and performance of amorphous InGaZnO thin-film transistors (TFTs) deposited by using atmospheric-pressure PECVD. The H2plasma-treateda-IGZO channel has shown significant improvement in bias stress induced instability with a minuscule threshold voltage shift (ΔVth) of 0.31 and -0.17 V under positive gate bias stress (PBS) and negative gate bias stress (NBS), respectively. With the aid of the energy band diagram, the proposed work demonstrates the formation of negative species O2-and positive species H2O+in the backchannel under PBS and NBS in addition to ionized oxygen vacancy (Vo) defects ata-IGZO/ZrO2interfaces are the reason for gate bias instability which could be effectively suppressed within situH2plasma treatment. From the experimental result, it is observed that the electrical performance such as field-effect mobility (μFE), on-off current ratio (Ion/Ioff), and subthreshold swing improved significantly byin situH2plasma treatment with passivation of interface trap density and bulk trap defects.
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Affiliation(s)
- Om Kumar Prasad
- International College of Semiconductor Technology, National Yang-Ming Chiao Tung University, Hsinchu, Taiwan
| | - Srikant Kumar Mohanty
- UST-IPPP, College of Electrical and Computer Engineering, National Yang-Ming Chiao Tung University, Hsinchu, Taiwan
| | - Chien Hung Wu
- Department of Optoelectronics and Materials Engineering, Chung Hua University, Hsinchu, Taiwan
| | - Tsung Ying Yu
- Department of Electronics Engineering, National Yang-Ming Chiao Tung University, Hsinchu, Taiwan
| | - Kow Ming Chang
- Department of Electronics Engineering, National Yang-Ming Chiao Tung University, Hsinchu, Taiwan
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11
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Shin W, Jung G, Hong S, Jeong Y, Park J, Kim D, Jang D, Kwon D, Bae JH, Park BG, Lee JH. Proposition of deposition and bias conditions for optimal signal-to-noise-ratio in resistor- and FET-type gas sensors. NANOSCALE 2020; 12:19768-19775. [PMID: 32966525 DOI: 10.1039/d0nr04406g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In the field of gas sensor studies, most researchers are focusing on improving the response of the sensors to detect a low concentration of gas. However, factors that make a large response, such as abundant or strong adsorption sites, also work as a source of noise, resulting in a trade-off between response and noise. Thus, the response alone cannot fully evaluate the performance of sensors, and the signal-to-noise-ratio (SNR) should additionally be considered to design gas sensors with optimal performance. In this regard, thin-film-type sensing materials are good candidates thanks to their moderate response and noise level. In this paper, we investigate the effects of radio frequency (RF) sputtering power for deposition of sensing materials on the SNR of resistor- and field-effect transistor (FET)-type gas sensors fabricated on the same Si wafer. In the case of resistor-type gas sensors, the deposition conditions that improve the response also worsen the noise either by increasing the scattering at the bulk or damaging the interface of the sensing material. Among resistor-type gas sensors with sensing materials deposited with different RF powers, a sensor with low noise shows the largest SNR despite its small response. However, the noise of FET-type gas sensors is not affected by changes in RF power and thus there is no trade-off between response and noise. The results reveal different noise sources depending on the deposition conditions of the sensing material, and provide design guidelines for resistor- and FET-type gas sensors considering noise for optimal performance.
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Affiliation(s)
- Wonjun Shin
- Department of Electrical and Computer Engineering and Inter-university Semiconductor Research Center, Seoul National University, Seoul 08826, Republic of Korea.
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Wang H, He J, Xu Y, André N, Zeng Y, Flandre D, Liao L, Li G. Impact of hydrogen dopant incorporation on InGaZnO, ZnO and In2O3 thin film transistors. Phys Chem Chem Phys 2020; 22:1591-1597. [DOI: 10.1039/c9cp05050g] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Hydrogen (H) dopants’ role and active defects inside n-type metal oxide semiconductors (MOXs) are comprehensively studied via continuous H plasma treatment.
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Affiliation(s)
- Huiru Wang
- Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices
- School of Physics and Electronics
- Hunan University
- Changsha 410082
- China
| | - Jiawei He
- School of Physics and Technology
- Wuhan University
- Wuhan 430072
- China
| | - Yongye Xu
- Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices
- School of Physics and Electronics
- Hunan University
- Changsha 410082
- China
| | - Nicolas André
- The ICTEAM Institute
- Université Catholique de Louvain
- Louvain-la-Neuve B-1348
- Belgium
| | - Yun Zeng
- Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices
- School of Physics and Electronics
- Hunan University
- Changsha 410082
- China
| | - Denis Flandre
- Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices
- School of Physics and Electronics
- Hunan University
- Changsha 410082
- China
| | - Lei Liao
- Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices
- School of Physics and Electronics
- Hunan University
- Changsha 410082
- China
| | - Guoli Li
- Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices
- School of Physics and Electronics
- Hunan University
- Changsha 410082
- China
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Influence of N2/O2 Partial Pressure Ratio during Channel Layer Deposition on the Temperature and Light Stability of a-InGaZnO TFTs. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9091880] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The electrical characteristics of amorphous InGaZnO (a-IGZO) thin film transistors (TFTs) deposited with different N2/O2 partial pressure ratios (PN/O) are investigated. It is found that the device with 20% PN/O exhibits enhanced electrical stability after positive-bias-stress temperature (PBST) and negative-bias-stress illumination (NBSI), presenting decreased threshold voltage drift (ΔVth). Compared to the N-free TFT, the average effective interface barrier energy (Eτ) of the TFT with 20% PN/O is increased from 0.37 eV to 0.57 eV during the bias-stress process, which agrees with the suppressed ΔVth from 3.0 V to 1.12 V after the PBS at T = 70 °C. X-ray photoelectron spectroscopy analysis revealed that the enhanced stability of the a-IGZO TFT with 20% PN/O should be ascribed to the control of oxygen vacancy defects at the interfacial region.
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Xu H, Xu M, Li M, Chen Z, Zou J, Wu W, Qiao X, Tao H, Wang L, Ning H, Ma D, Peng J. Trap-Assisted Enhanced Bias Illumination Stability of Oxide Thin Film Transistor by Praseodymium Doping. ACS APPLIED MATERIALS & INTERFACES 2019; 11:5232-5239. [PMID: 30640426 DOI: 10.1021/acsami.8b18329] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Praseodymium-doped indium zinc oxide (PrIZO) has been employed as the channel layer of thin-film transistors (TFTs). The TFTs with Pr doping exhibited a remarkable suppression of the light-induced instability. A negligible photo-response and remarkable enhancement in negative gate bias stress under illumination (NBIS) were achieved in the PrIZO-TFTs. Meanwhile, the PrIZO-TFTs showed reasonable characteristics with a high-field-effect mobility of 26.3 cm2/V s, SS value of 0.28 V/decade, and Ion/ Ioff ratio of 108. X-ray photoelectron spectroscopy, microwave photoconductivity decay, and photoluminescence spectra were employed to analyze the effects of the Pr concentrations on the performance of PrIZO-TFTs. We disclosed that acceptor-like trap states induced by Pr ions might lead to the suppression of photo-induced carrier in conduction band, which is a new strategy for improving illumination stability of amorphous oxide semiconductors. Finally, a prototype of fully transparent AMOLED display was successfully fabricated to demonstrate the potential of Pr-doping TFTs applied in transparent devices.
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Affiliation(s)
- Hua Xu
- State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , China
- Guangzhou New Vision Optoelectronic Corporation, Limited , Guangzhou 510530 , China
| | - Miao Xu
- State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , China
- Guangzhou New Vision Optoelectronic Corporation, Limited , Guangzhou 510530 , China
| | - Min Li
- Guangzhou New Vision Optoelectronic Corporation, Limited , Guangzhou 510530 , China
| | - Zikai Chen
- Guangzhou New Vision Optoelectronic Corporation, Limited , Guangzhou 510530 , China
| | - Jianhua Zou
- Guangzhou New Vision Optoelectronic Corporation, Limited , Guangzhou 510530 , China
| | - Weijing Wu
- State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , China
| | - Xianfeng Qiao
- State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , China
| | - Hong Tao
- Guangzhou New Vision Optoelectronic Corporation, Limited , Guangzhou 510530 , China
| | - Lei Wang
- State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , China
- Guangzhou New Vision Optoelectronic Corporation, Limited , Guangzhou 510530 , China
| | - Honglong Ning
- State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , China
| | - Dongge Ma
- State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , China
| | - Junbiao Peng
- State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , China
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Role of Hydrogen in Active Layer of Oxide-Semiconductor-Based Thin Film Transistors. CRYSTALS 2019. [DOI: 10.3390/cryst9020075] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Hydrogen in oxide systems plays a very important role in determining the major physical characteristics of such systems. In this study, we investigated the effect of hydrogen in oxide host systems for various oxygen environments that acted as amorphous oxide semiconductors. The oxygen environment in the sample was controlled by the oxygen gas partial pressure in the radio-frequency-sputtering process. It was confirmed that the hydrogen introduced by the passivation layer not only acted as a “killer” of oxygen deficiencies but also as the “creator” of the defects depending on the density of oxide states. Even if hydrogen is not injected, its role can change owing to unintentionally injected hydrogen, which leads to conflicting results. We discuss herein the correlation with hydrogen in the oxide semiconductor with excess or lack of oxygen through device simulation and elemental analysis.
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