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Liu M, Zang H, Jia Y, Jiang K, Ben J, Lv S, Li D, Sun X, Li D. Effect and Regulation Mechanism of Post-deposition Annealing on the Ferroelectric Properties of AlScN Thin Films. ACS Appl Mater Interfaces 2024; 16:16427-16435. [PMID: 38523333 DOI: 10.1021/acsami.3c17282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/26/2024]
Abstract
Integrating ferroelectric AlScN with III-N semiconductors to enhance the performance and tunability of nitride devices requires high-quality AlScN films. This work focuses on the effect and regulation mechanism of post-annealing in pure N2 on the crystal quality and ferroelectric properties of AlScN films. It is found that the crystal quality improves with increasing annealing temperatures. Remarkably, the leakage current of AlScN films caused by grain boundaries could be reduced by four orders of magnitude after annealing at 400 °C. The crystal growth dynamics simulations and band structure calculations indicate that the energy supplied by the temperature facilitates the evolution of abnormally oriented grains to have a better c-axis orientation, resulting in the defect states at the Fermi-level disappearing, which is mainly the reason for the leakage current decrease. More interestingly, the reduction of leakage current leads to the previously leaking region exhibiting ferroelectric properties, which is of great significance to improve the ferroelectricity of AlScN and ensure the uniformity of devices. Furthermore, annealing enhances the tensile strain on the film, which flattens the energy landscape of ferroelectric switching and reduces the coercive field. However, the risk of incorporation of oxygen will also be increased if the annealing temperatures are higher than 400 °C, which will not only reduce the relative displacement of metal atoms and nitrogen atoms in AlScN but also enhance the ferroelectric depolarization field, leading to the remnant polarization decreasing dramatically. These discoveries facilitate a deeper understanding of the influencing mechanism on the ferroelectric properties of AlScN films and provide a direction for obtaining high-quality AlScN.
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Affiliation(s)
- Mingrui Liu
- State Key Laboratory of Luminescence Science and Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
| | - Hang Zang
- State Key Laboratory of Luminescence Science and Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
| | - Yuping Jia
- State Key Laboratory of Luminescence Science and Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
| | - Ke Jiang
- State Key Laboratory of Luminescence Science and Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
| | - Jianwei Ben
- State Key Laboratory of Luminescence Science and Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
| | - Shunpeng Lv
- State Key Laboratory of Luminescence Science and Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
| | - Dan Li
- State Key Laboratory of Luminescence Science and Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
| | - Xiaojuan Sun
- State Key Laboratory of Luminescence Science and Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
| | - Dabing Li
- State Key Laboratory of Luminescence Science and Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
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2
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Lin YS, Lu CC. AlGaN/GaN Metal Oxide Semiconductor High-Electron Mobility Transistors with Annealed TiO 2 as Passivation and Dielectric Layers. Micromachines (Basel) 2023; 14:1183. [PMID: 37374767 DOI: 10.3390/mi14061183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 05/28/2023] [Accepted: 05/30/2023] [Indexed: 06/29/2023]
Abstract
This paper reports on improved AlGaN/GaN metal oxide semiconductor high-electron mobility transistors (MOS-HEMTs). TiO2 is used to form the dielectric and passivation layers. The TiO2 film is characterized using X-ray photoemission spectroscopy (XPS), Raman spectroscopy, and transmission electron microscopy (TEM). The quality of the gate oxide is improved by annealing at 300 °C in N2. Experimental results indicate that the annealed MOS structure effectively reduces the gate leakage current. The high performance of the annealed MOS-HEMTs and their stable operation at elevated temperatures up to 450 K is demonstrated. Furthermore, annealing improves their output power characteristics.
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Affiliation(s)
- Yu-Shyan Lin
- Department of Materials Science and Engineering, National Dong Hwa University, Hualien 974301, Taiwan
- Department of Opto-Electronic Engineering, National Dong Hwa University, Hualien 974301, Taiwan
| | - Chi-Che Lu
- Department of Materials Science and Engineering, National Dong Hwa University, Hualien 974301, Taiwan
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3
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Han Y, Ruan Y, Xue M, Wu Y, Shi M, Song Z, Zhou Y, Teng J. Effect of Annealing Time on the Cyclic Characteristics of Ceramic Oxide Thin Film Thermocouples. Micromachines (Basel) 2022; 13:1970. [PMID: 36422398 PMCID: PMC9694502 DOI: 10.3390/mi13111970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 10/31/2022] [Accepted: 11/11/2022] [Indexed: 06/16/2023]
Abstract
Oxide thin film thermocouples (TFTCs) are widely used in high-temperature environment measurements and have the advantages of good stability and high thermoelectric voltage. However, different annealing processes affect the performance of TFTCs. This paper studied the impact of different annealing times on the cyclic characteristics of ceramic oxide thin film thermocouples. ITO/In2O3 TFTCs were prepared on alumina ceramics by a screen printing method, and the samples were annealed at different times. The microstructure of the ITO film was studied by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The results show that when the annealing temperature is fixed, the stability of the thermocouple is worst when it is annealed for 2 h. Extending the annealing time can improve the properties of the film, increase the density, slow down oxidation, and enhance the thermal stability of the thermocouple. The thermal cycle test results show that the sample can reach five temperature rise and fall cycles, more than 50 h, and can meet the needs of stable measurement in high temperature and harsh environments.
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Affiliation(s)
- Yuning Han
- Department of Electronic Information, Beijing Information Science and Technology University, Beijing 100192, China
| | - Yong Ruan
- Department of Precision Instruments, Tsinghua University, Beijing 100084, China
| | - Meixia Xue
- Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Yu Wu
- Department of Precision Instruments, Tsinghua University, Beijing 100084, China
- Qiyuan Laboratory, Beijing 100094, China
| | - Meng Shi
- MEMS Institute of Zibo National High-Tech Industrial Development Zone, Zibo 255000, China
| | - Zhiqiang Song
- MEMS Institute of Zibo National High-Tech Industrial Development Zone, Zibo 255000, China
| | - Yuankai Zhou
- MEMS Institute of Zibo National High-Tech Industrial Development Zone, Zibo 255000, China
| | - Jiao Teng
- Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083, China
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4
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Saito M, Kitamura M, Ide Y, Nguyen MH, Le BD, Mai AT, Miyashiro D, Mayama S, Umemura K. An Efficient Method of Observing Diatom Frustules via Digital Holographic Microscopy. Microsc Microanal 2022; 28:1-5. [PMID: 36124414 DOI: 10.1017/s1431927622012508] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Herein, we propose a convenient method to enable pretreatment of target objects using digital holographic microscopy (DHM). As a test sample, we used diatom frustules (Nitzschia sp.) as the target objects. In the generally used sample preparation method, the frustule suspension is added dropwise onto a glass substrate or into a glass chamber. While our work confirms good observation of purified frustules using the typical sample preparation method, we also demonstrate a new procedure to observe unseparated structures of frustules prepared by baking them on a mica surface. The baked frustules on the mica surface were transferred to a glass chamber with 1% sodium dodecyl sulfate solution. In this manner, the unseparated structures of the diatom frustules were clearly observed. Furthermore, metal-coated frustules prepared by sputtering onto them on a mica surface were also clearly observed using the same procedure. Our method can be applied for the observation of any target object that is pretreated on a solid surface. We expect our proposed method to be a basis for establishing DHM techniques for microscopic observations of biomaterials.
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Affiliation(s)
- Makoto Saito
- Biophysics Section, Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo 162-8601, Japan
| | - Masaki Kitamura
- Biophysics Section, Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo 162-8601, Japan
| | - Yuki Ide
- Biophysics Section, Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo 162-8601, Japan
| | - Minh Hieu Nguyen
- VNU University of University of Science, 334 Nguyen Trai, Thanh Xuan, Hanoi, Vietnam
| | - Binh Duong Le
- National Center for Technological Progress, 25 Le Thanh Tong, Hoan Kiem, Hanoi, Vietnam
| | - Anh Tuan Mai
- VNU University of Engineering and Technology, 144 Xuan Thuy, Cau Giay, Hanoi, Vietnam
| | - Daisuke Miyashiro
- ScienceCafe MC2 Co., Ltd., 3-88 Hanasaki-Cho, Yokohama Naka-ku, Kanagawa 231-0063, Japan
| | - Shigeki Mayama
- Tokyo Diatomology Labo, 2-3-2 Nukuikitamachi, Koganei, Tokyo 184-0015, Japan
| | - Kazuo Umemura
- Biophysics Section, Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo 162-8601, Japan
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Sun H, Lian X, Lv Y, Liu Y, Xu C, Dai J, Wu Y, Wang G. Effect of Annealing on the Microstructure and SERS Performance of Mo-48.2% Ag Films. Materials (Basel) 2020; 13:E4205. [PMID: 32971755 PMCID: PMC7560463 DOI: 10.3390/ma13184205] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 09/15/2020] [Accepted: 09/18/2020] [Indexed: 12/11/2022]
Abstract
Mo-48.2% Ag films were fabricated by direct current (DC) magnetron sputtering and annealed in an argon atmosphere. The effects of annealing on the surface morphology, resistivity and surface-enhanced Raman scattering (SERS) performance of Mo-48.2% Ag films were investigated. Results show a mass of polyhedral Ag particles grown on the annealed Mo-48.2% Ag films' surface, which are different from that of as-deposited Mo-Ag film. Moreover, the thickness and the resistivity of Mo-48.2% Ag films gradually decrease as the annealing temperature increases. Furthermore, finite-difference time-domain (FDTD) simulations proved that the re-deposition Ag layer increases the "hot spots" between adjacent Ag nanoparticles, thereby greatly enhancing the local electromagnetic (EM) field. The Ag layer/annealed Mo-48.2% Ag films can identify crystal violet (CV) with concentration lower than 5 × 10-10 M (1 mol/L = 1 M), which indicated that this novel type of particles/films can be applied as ultrasensitive SERS substrates.
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Affiliation(s)
- Haoliang Sun
- School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023, China; (X.L.); (Y.L.); (Y.L.); (C.X.); (J.D.); (Y.W.); (G.W.)
- Collaborative Innovation Center of Nonferrous Metals Henan Province, Luoyang 471003, China
| | - Xinxin Lian
- School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023, China; (X.L.); (Y.L.); (Y.L.); (C.X.); (J.D.); (Y.W.); (G.W.)
| | - Yuanjiang Lv
- School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023, China; (X.L.); (Y.L.); (Y.L.); (C.X.); (J.D.); (Y.W.); (G.W.)
| | - Yuanhao Liu
- School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023, China; (X.L.); (Y.L.); (Y.L.); (C.X.); (J.D.); (Y.W.); (G.W.)
| | - Chao Xu
- School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023, China; (X.L.); (Y.L.); (Y.L.); (C.X.); (J.D.); (Y.W.); (G.W.)
| | - Jiwei Dai
- School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023, China; (X.L.); (Y.L.); (Y.L.); (C.X.); (J.D.); (Y.W.); (G.W.)
| | - Yilin Wu
- School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023, China; (X.L.); (Y.L.); (Y.L.); (C.X.); (J.D.); (Y.W.); (G.W.)
| | - Guangxin Wang
- School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023, China; (X.L.); (Y.L.); (Y.L.); (C.X.); (J.D.); (Y.W.); (G.W.)
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Du H, Xie G, Zhang Q. Enhanced Room Temperature NO 2 Sensing Performance of RGO Nanosheets by Building RGO/SnO 2 Nanocomposite System. Sensors (Basel) 2019; 19:s19214650. [PMID: 31717730 PMCID: PMC6864535 DOI: 10.3390/s19214650] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 10/17/2019] [Accepted: 10/24/2019] [Indexed: 11/16/2022]
Abstract
RGO/SnO2 nanocomposites were prepared by a simple blending method and then airbrushed on interdigitated electrodes to obtain the corresponding gas sensors. The characterizations of SEM, TEM, Raman, XRD and FTIR were used to characterize the microstructures, morphologies and surface chemical compositions of the nanocomposites, indicating that the two materials coexist in the composite films and the concentration of surface defects is affected by the amount of SnO2 nanoparticles. It is also found that the room temperature sensing performance of RGO to NO2 can be improved by introducing appropriate amount of SnO2 nanoparticles. The enhanced NO2 sensing properties are attributed to the rough surface structure and increased surface area and surface defects of the nanocomposite films. Since further reduction of RGO, heat treating the sensing films resulted in a decrease in the response and recovery times of the sensors. Furthermore, the sensor annealed at 200 ∘C exhibited a small baseline drift, wide detection range, good linearity, high stability and better selectivity.
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Affiliation(s)
- Hongfei Du
- School of Optoelectronic Science and Engineering, State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China (UESTC), Chengdu 610054, China; (H.D.); (G.X.)
- School of Mathematical Sciences, University of Electronic Sciences and Technology of China (UESTC), Chengdu 611731, China
| | - Guangzhong Xie
- School of Optoelectronic Science and Engineering, State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China (UESTC), Chengdu 610054, China; (H.D.); (G.X.)
| | - Qiuping Zhang
- Key Laboratory of Information Materials of Sichuan Province, School of Electrical and Information Engineering, Southwest University for Nationalities, Chengdu 610041, China
- Correspondence:
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7
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Zhu Z, Zhan L, Shih TM, Wan W, Lu J, Huang J, Guo S, Zhou Y, Cai W. Critical Annealing Temperature for Stacking Orientation of Bilayer Graphene. Small 2018; 14:e1802498. [PMID: 30160374 DOI: 10.1002/smll.201802498] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 07/26/2018] [Indexed: 06/08/2023]
Abstract
It is rarely reported that stacking orientations of bilayer graphene (BLG) can be manipulated by the annealing process. Most investigators have painstakingly fabricated this BLG by chemical vapor deposition growth or mechanical means. Here, it is discovered that, at ≈600 °C, called the critical annealing temperature (CAT), most stacking orientations collapse into strongly coupled or AB-stacked states. This phenomenon is governed (i) macroscopically by the stress generation and release in top graphene domains, evolving from mild ripples to sharp billows in certain local areas, and (ii) microscopically by the principle of minimal potential obeyed by carbon atoms that have acquired sufficient thermal energy at CAT. Conspicuously, evolutions of stacking orientations in Raman mappings under various annealing temperatures are observed. Furthermore, MoS2 synthesized on BLG is used to directly observe crystal orientations of top and bottom graphene layers. The finding of CAT provides a guide for the fabrication of strongly coupled or AB-stacked BLG, and can be applied to aligning other 2D heterostructures.
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Affiliation(s)
- Zhenwei Zhu
- Department of Physics, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Key Laboratory of Low Dimensional Condensed Matter Physics (Department of Education of Fujian Province), Xiamen University, Xiamen, 361005, China
- Jiujiang Research Institute of Xiamen University, Jiujiang, 332000, China
- Department of Mechanical Engineering and Materials Science, Rice University, Houston, TX, 77005, USA
| | - Linjie Zhan
- Department of Physics, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Key Laboratory of Low Dimensional Condensed Matter Physics (Department of Education of Fujian Province), Xiamen University, Xiamen, 361005, China
- Jiujiang Research Institute of Xiamen University, Jiujiang, 332000, China
| | - Tien-Mo Shih
- Department of Physics, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Key Laboratory of Low Dimensional Condensed Matter Physics (Department of Education of Fujian Province), Xiamen University, Xiamen, 361005, China
- Tianming Physics Research Institute, Changtai, 363900, China
| | - Wen Wan
- Department of Physics, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Key Laboratory of Low Dimensional Condensed Matter Physics (Department of Education of Fujian Province), Xiamen University, Xiamen, 361005, China
- Jiujiang Research Institute of Xiamen University, Jiujiang, 332000, China
| | - Jie Lu
- Department of Physics, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Key Laboratory of Low Dimensional Condensed Matter Physics (Department of Education of Fujian Province), Xiamen University, Xiamen, 361005, China
- Jiujiang Research Institute of Xiamen University, Jiujiang, 332000, China
| | - Junjie Huang
- Department of Physics, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Key Laboratory of Low Dimensional Condensed Matter Physics (Department of Education of Fujian Province), Xiamen University, Xiamen, 361005, China
- Jiujiang Research Institute of Xiamen University, Jiujiang, 332000, China
| | - Shengshi Guo
- Department of Physics, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Key Laboratory of Low Dimensional Condensed Matter Physics (Department of Education of Fujian Province), Xiamen University, Xiamen, 361005, China
- Jiujiang Research Institute of Xiamen University, Jiujiang, 332000, China
| | - Yinghui Zhou
- Department of Physics, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Key Laboratory of Low Dimensional Condensed Matter Physics (Department of Education of Fujian Province), Xiamen University, Xiamen, 361005, China
- Jiujiang Research Institute of Xiamen University, Jiujiang, 332000, China
| | - Weiwei Cai
- Department of Physics, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Key Laboratory of Low Dimensional Condensed Matter Physics (Department of Education of Fujian Province), Xiamen University, Xiamen, 361005, China
- Jiujiang Research Institute of Xiamen University, Jiujiang, 332000, China
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8
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Chen HC, Chang TC, Lai WC, Chen GF, Chen BW, Hung YJ, Chang KJ, Cheng KC, Huang CS, Chen KK, Lu HH, Lin YH. Cyclical Annealing Technique To Enhance Reliability of Amorphous Metal Oxide Thin Film Transistors. ACS Appl Mater Interfaces 2018; 10:25866-25870. [PMID: 29481039 DOI: 10.1021/acsami.7b16307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
This study introduces a cyclical annealing technique that enhances the reliability of amorphous indium-gallium-zinc-oxide (a-IGZO) via-type structure thin film transistors (TFTs). By utilizing this treatment, negative gate-bias illumination stress (NBIS)-induced instabilities can be effectively alleviated. The cyclical annealing provides several cooling steps, which are exothermic processes that can form stronger ionic bonds. An additional advantage is that the total annealing time is much shorter than when using conventional long-term annealing. With the use of cyclical annealing, the reliability of the a-IGZO can be effectively optimized, and the shorter process time can increase fabrication efficiency.
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Affiliation(s)
- Hong-Chih Chen
- Department of Photonics , National Cheng Kung University , Tainan 701 , Taiwan R. O. C
| | | | - Wei-Chih Lai
- Department of Photonics , National Cheng Kung University , Tainan 701 , Taiwan R. O. C
| | | | | | | | - Kuo-Jui Chang
- New Display Process Research Division , AU Optronics Corporation , Hsinchu 300 , Taiwan R. O. C
| | - Kai-Chung Cheng
- New Display Process Research Division , AU Optronics Corporation , Hsinchu 300 , Taiwan R. O. C
| | - Chen-Shuo Huang
- New Display Process Research Division , AU Optronics Corporation , Hsinchu 300 , Taiwan R. O. C
| | - Kuo-Kuang Chen
- New Display Process Research Division , AU Optronics Corporation , Hsinchu 300 , Taiwan R. O. C
| | - Hsueh-Hsing Lu
- New Display Process Research Division , AU Optronics Corporation , Hsinchu 300 , Taiwan R. O. C
| | - Yu-Hsin Lin
- New Display Process Research Division , AU Optronics Corporation , Hsinchu 300 , Taiwan R. O. C
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Feng R, Song W, Li H, Qi Y, Qiao H, Li L. Effects of Annealing on the Residual Stress in γ-TiAl Alloy by Molecular Dynamics Simulation. Materials (Basel) 2018; 11:ma11061025. [PMID: 29914121 PMCID: PMC6025271 DOI: 10.3390/ma11061025] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 06/08/2018] [Accepted: 06/13/2018] [Indexed: 11/25/2022]
Abstract
In this paper, molecular dynamics simulations are performed to study the annealing process of γ-TiAl alloy with different parameters after introducing residual stress into prepressing. By mainly focusing on the dynamic evolution process of microdefects during annealing and the distribution of residual stress, the relationship between microstructure and residual stress is investigated. The results show that there is no phase transition during annealing, but atom distortion occurs with the change of temperature, and the average grain size slightly increases after annealing. There are some atom clusters in the grains, with a few point defects, and the point defect concentration increases with the rise in temperature, and vice versa; the higher the annealing temperature, the fewer the point defects in the grain after annealing. Due to the grain boundary volume shrinkage and and an increase in the plastic deformation of the grain boundaries during cooling, stress is released, and the average residual stress along Y and Z directions after annealing is less than the average residual stress after prepressing.
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Affiliation(s)
- Ruicheng Feng
- School of Mechanical and Electronical Engineering, Lanzhou University of Technology, Lanzhou 730050, China.
- Key Laboratory of Digital Manufacturing Technology and Application, Ministry of Education, Lanzhou University of Technology, Lanzhou 730050, China.
| | - Wenyuan Song
- School of Mechanical and Electronical Engineering, Lanzhou University of Technology, Lanzhou 730050, China.
| | - Haiyan Li
- School of Mechanical and Electronical Engineering, Lanzhou University of Technology, Lanzhou 730050, China.
- Key Laboratory of Digital Manufacturing Technology and Application, Ministry of Education, Lanzhou University of Technology, Lanzhou 730050, China.
| | - Yongnian Qi
- School of Mechanical and Electronical Engineering, Lanzhou University of Technology, Lanzhou 730050, China.
| | - Haiyang Qiao
- School of Mechanical and Electronical Engineering, Lanzhou University of Technology, Lanzhou 730050, China.
| | - Longlong Li
- School of Mechanical and Electronical Engineering, Lanzhou University of Technology, Lanzhou 730050, China.
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