1
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Hwang J, Goh Y, Jeon S. Physics, Structures, and Applications of Fluorite-Structured Ferroelectric Tunnel Junctions. Small 2024; 20:e2305271. [PMID: 37863823 DOI: 10.1002/smll.202305271] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 09/11/2023] [Indexed: 10/22/2023]
Abstract
The interest in ferroelectric tunnel junctions (FTJ) has been revitalized by the discovery of ferroelectricity in fluorite-structured oxides such as HfO2 and ZrO2 . In terms of thickness scaling, CMOS compatibility, and 3D integration, these fluorite-structured FTJs provide a number of benefits over conventional perovskite-based FTJs. Here, recent developments involving all FTJ devices with fluorite structures are examined. The transport mechanism of fluorite-structured FTJs is explored and contrasted with perovskite-based FTJs and other 2-terminal resistive switching devices starting with the operation principle and essential parameters of the tunneling electroresistance effect. The applications of FTJs, such as neuromorphic devices, logic-in-memory, and physically unclonable function, are then discussed, along with several structural approaches to fluorite-structure FTJs. Finally, the materials and device integration difficulties related to fluorite-structure FTJ devices are reviewed. The purpose of this review is to outline the theories, physics, fabrication processes, applications, and current difficulties associated with fluorite-structure FTJs while also describing potential future possibilities for optimization.
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Affiliation(s)
- Junghyeon Hwang
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, South Korea
| | - Youngin Goh
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, South Korea
| | - Sanghun Jeon
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, South Korea
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2
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Li Z, Wei J, Meng J, Liu Y, Yu J, Wang T, Xu K, Liu P, Zhu H, Chen S, Sun QQ, Zhang DW, Chen L. The Doping Effect on the Intrinsic Ferroelectricity in Hafnium Oxide-Based Nano-Ferroelectric Devices. Nano Lett 2023; 23:4675-4682. [PMID: 36913490 DOI: 10.1021/acs.nanolett.3c00085] [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: 05/25/2023]
Abstract
Hafnium oxide (HfO2)-based ferroelectric tunnel junctions (FTJs) have been extensively evaluated for high-speed and low-power memory applications. Herein, we investigated the influence of Al content in HfAlO thin films on the ferroelectric characteristics of HfAlO-based FTJs. Among HfAlO devices with different Hf/Al ratios (20:1, 34:1, and 50:1), the HfAlO device with Hf/Al ratio of 34:1 exhibited the highest remanent polarization and excellent memory characteristics and, thereby, the best ferroelectricity among the investigated devices. Furthermore, first-principal analyses verified that HfAlO thin films with Hf/Al ratio of 34:1 promoted the formation of the orthorhombic phase against the paraelectric phase as well as alumina impurities and, thus, enhanced the ferroelectricity of the device, providing theoretical support for supporting experimental results. The findings of this study provide insights for developing HfAlO-based FTJs for next-generation in-memory computing applications.
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Affiliation(s)
- Zhenhai Li
- School of Microelectronics, Fudan University, Shanghai 200433, P. R. China
- Zhangjiang Fudan International Innovation Center, Shanghai 201203, P. R. China
| | - Jinchen Wei
- School of Microelectronics, Fudan University, Shanghai 200433, P. R. China
| | - Jialin Meng
- School of Microelectronics, Fudan University, Shanghai 200433, P. R. China
- Zhangjiang Fudan International Innovation Center, Shanghai 201203, P. R. China
| | - Yongkai Liu
- School of Microelectronics, Fudan University, Shanghai 200433, P. R. China
- Zhangjiang Fudan International Innovation Center, Shanghai 201203, P. R. China
| | - Jiajie Yu
- School of Microelectronics, Fudan University, Shanghai 200433, P. R. China
- Zhangjiang Fudan International Innovation Center, Shanghai 201203, P. R. China
| | - Tianyu Wang
- School of Microelectronics, Fudan University, Shanghai 200433, P. R. China
- Zhangjiang Fudan International Innovation Center, Shanghai 201203, P. R. China
| | - Kangli Xu
- School of Microelectronics, Fudan University, Shanghai 200433, P. R. China
- Zhangjiang Fudan International Innovation Center, Shanghai 201203, P. R. China
| | - Pei Liu
- School of Microelectronics, Fudan University, Shanghai 200433, P. R. China
- Zhangjiang Fudan International Innovation Center, Shanghai 201203, P. R. China
| | - Hao Zhu
- School of Microelectronics, Fudan University, Shanghai 200433, P. R. China
- Zhangjiang Fudan International Innovation Center, Shanghai 201203, P. R. China
| | - Shiyou Chen
- School of Microelectronics, Fudan University, Shanghai 200433, P. R. China
| | - Qing-Qing Sun
- School of Microelectronics, Fudan University, Shanghai 200433, P. R. China
- Zhangjiang Fudan International Innovation Center, Shanghai 201203, P. R. China
| | - David Wei Zhang
- School of Microelectronics, Fudan University, Shanghai 200433, P. R. China
- Zhangjiang Fudan International Innovation Center, Shanghai 201203, P. R. China
| | - Lin Chen
- School of Microelectronics, Fudan University, Shanghai 200433, P. R. China
- Zhangjiang Fudan International Innovation Center, Shanghai 201203, P. R. China
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3
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Tang W, Zhang X, Yu H, Gao L, Zhang Q, Wei X, Hong M, Gu L, Liao Q, Kang Z, Zhang Z, Zhang Y. A van der Waals Ferroelectric Tunnel Junction for Ultrahigh-Temperature Operation Memory. Small Methods 2022; 6:e2101583. [PMID: 35212464 DOI: 10.1002/smtd.202101583] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/27/2022] [Indexed: 06/14/2023]
Abstract
Facing the constant scaling down and thus increasingly severe self-heating effect, developing ultrathin and heat-insensitive ferroelectric devices is essential for future electronics. However, conventional ultrathin ferroelectrics and most 2D ferroelectric materials (2DFMs) are not suitable for high-temperature operation due to their low Curie temperature. Here, by using few-layer α-In2 Se3 , a special 2DFM with high Curie temperature, van der Waals (vdW) ferroelectric tunnel junction (FTJ) memories that deliver outstanding and reliable performance at both room and high temperatures are constructed. The vdW FTJs offer a large on/off ratio of 104 at room temperature and still reveal excellent on/off ratio at an ultrahigh temperature of 470 K, which will fail down other 2DFMs. Moreover, long retention and reliable cyclic endurance at high temperature are achieved, showing robust thermal stability of the vdW FTJ memory. The observations of this work demonstrate an exciting promise of α-In2 Se3 for reliable service in high temperature either from self-heating or harsh environments.
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Affiliation(s)
- Wenhui Tang
- Academy for Advanced Interdisciplinary Science and Technology, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, P. R. China
| | - Xiankun Zhang
- Academy for Advanced Interdisciplinary Science and Technology, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, P. R. China
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Advanced Energy Materials and Technologies, University of Science and Technology Beijing, Beijing, 100083, P. R. China
| | - Huihui Yu
- Academy for Advanced Interdisciplinary Science and Technology, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, P. R. China
| | - Li Gao
- Academy for Advanced Interdisciplinary Science and Technology, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, P. R. China
| | - Qinghua Zhang
- Collaborative Innovation Center of Quantum Matter, Beijing, 100871, China
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100080, China
| | - Xiaofu Wei
- Academy for Advanced Interdisciplinary Science and Technology, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, P. R. China
| | - Mengyu Hong
- Academy for Advanced Interdisciplinary Science and Technology, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, P. R. China
| | - Lin Gu
- Collaborative Innovation Center of Quantum Matter, Beijing, 100871, China
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100080, China
| | - Qingliang Liao
- Academy for Advanced Interdisciplinary Science and Technology, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, P. R. China
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Advanced Energy Materials and Technologies, University of Science and Technology Beijing, Beijing, 100083, P. R. China
| | - Zhuo Kang
- Academy for Advanced Interdisciplinary Science and Technology, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, P. R. China
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Advanced Energy Materials and Technologies, University of Science and Technology Beijing, Beijing, 100083, P. R. China
| | - Zheng Zhang
- Academy for Advanced Interdisciplinary Science and Technology, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, P. R. China
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Advanced Energy Materials and Technologies, University of Science and Technology Beijing, Beijing, 100083, P. R. China
| | - Yue Zhang
- Academy for Advanced Interdisciplinary Science and Technology, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, P. R. China
- Beijing Advanced Innovation Center for Materials Genome Engineering, Beijing Key Laboratory for Advanced Energy Materials and Technologies, University of Science and Technology Beijing, Beijing, 100083, P. R. China
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4
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Andreeva N, Petukhov A, Vilkov O, Petraru A, Luchinin V. Local Electric Property Modification of Ferroelectric Tunnel Junctions Induced by Variation of Polarization Charge Screening Conditions under Measurement with Scanning Probe Techniques. Nanomaterials (Basel) 2021; 11:nano11123323. [PMID: 34947670 PMCID: PMC8703973 DOI: 10.3390/nano11123323] [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] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 12/01/2021] [Accepted: 12/03/2021] [Indexed: 11/26/2022]
Abstract
Scanning tunneling spectroscopy in ultrahigh vacuum conditions and conductive atomic-force microscopy in ambient conditions were used to study local electroresistive properties of ferroelectric tunnel junctions SrTiO3/La0.7Sr0.3MnO3/BaTiO3. Interestingly, experimental current-voltage characteristics appear to strongly depend on the measurement technique applied. It was found that screening conditions of the polarization charges at the interface with a top electrode differ for two scanning probe techniques. As a result, asymmetry of the tunnel barrier height for the opposite ferroelectric polarization orientations may be influenced by the method applied to study the local tunnel electroresistance. Our observations are well described by the theory of electroresistance in ferroelectric tunnel junctions. Based on this, we reveal the main factors that influence the polarization-driven local resistive properties of the device under study. Additionally, we propose an approach to enhance asymmetry of ferroelectric tunnel junctions during measurement. While keeping the high locality of scanning probe techniques, it helps to increase the difference in the value of tunnel electroresistance for the opposite polarization orientations.
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Affiliation(s)
- Natalia Andreeva
- Department of Micro- and Nanoelectronics, St. Petersburg Electrotechnical University ‘LETI’, 197376 Saint Petersburg, Russia;
- Correspondence:
| | - Anatoliy Petukhov
- Research Park, St. Petersburg State University, 198504 Saint Petersburg, Russia;
| | - Oleg Vilkov
- Department of Solid State Electronics, St. Petersburg State University, 198504 Saint Petersburg, Russia;
| | - Adrian Petraru
- Nanoelektronik, Technische Fakultät, Christian-Albrechts-Universität zu Kiel, 24143 Kiel, Germany;
| | - Victor Luchinin
- Department of Micro- and Nanoelectronics, St. Petersburg Electrotechnical University ‘LETI’, 197376 Saint Petersburg, Russia;
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5
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Yu J, Min KK, Kim Y, Kim S, Hwang S, Kim TH, Kim C, Kim H, Lee JH, Kwon D, Park BG. A novel physical unclonable function (PUF) using 16 × 16 pure-HfO xferroelectric tunnel junction array for security applications. Nanotechnology 2021; 32:485202. [PMID: 34399420 DOI: 10.1088/1361-6528/ac1dd5] [Citation(s) in RCA: 4] [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] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 08/16/2021] [Indexed: 06/13/2023]
Abstract
As the computing paradigm has shifted toward edge computing, improving the security of edge devices is attracting significant attention. However, because edge devices have limited resources in terms of power and area, it is difficult to apply a conventional cryptography system to protect them. On the other hand, as a simple security application, a physical unclonable function (PUF) can be implemented without power and area problems because it provides a security key by utilizing process variations without additional external circuits. Ferroelectric tunnel junctions (FTJs) are 2-terminal devices that store information by changing the resistance of a ferroelectric material, where the resistance is determined by the polarization states of the ferroelectric domains. Because polycrystalline ferroelectric materials have a multi-domain nature, domain variation can also be used as a randomness source to induce cell-to-cell variations along with process variations. In this paper, we demonstrate PUF operations of a low-power, small area 16 × 16 hafnium oxide (pure-HfOx)-based FTJ array using certain metrics. It is clear that the proposed array consisting of scaled FTJs has adequate randomness for security applications such that the array-level PUF operations are robust against model-based machine learning attacks.
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Affiliation(s)
- Junsu Yu
- Inter-University Semiconductor Research Center, Department of Electrical and Computer Engineering, Seoul National University, Seoul 151-744, Republic of Korea
| | - Kyung Kyu Min
- Inter-University Semiconductor Research Center, Department of Electrical and Computer Engineering, Seoul National University, Seoul 151-744, Republic of Korea
- SK Hynix Inc., Icheon 17336, Republic of Korea
| | - Yeonwoo Kim
- Inter-University Semiconductor Research Center, Department of Electrical and Computer Engineering, Seoul National University, Seoul 151-744, Republic of Korea
| | - Sihyun Kim
- Inter-University Semiconductor Research Center, Department of Electrical and Computer Engineering, Seoul National University, Seoul 151-744, Republic of Korea
| | - Sungmin Hwang
- Inter-University Semiconductor Research Center, Department of Electrical and Computer Engineering, Seoul National University, Seoul 151-744, Republic of Korea
| | - Tae-Hyeon Kim
- Inter-University Semiconductor Research Center, Department of Electrical and Computer Engineering, Seoul National University, Seoul 151-744, Republic of Korea
| | - Changha Kim
- Inter-University Semiconductor Research Center, Department of Electrical and Computer Engineering, Seoul National University, Seoul 151-744, Republic of Korea
| | - Hyungjin Kim
- Department of Electronic Engineering, Inha University, Incheon 22212, Republic of Korea
| | - Jong-Ho Lee
- Inter-University Semiconductor Research Center, Department of Electrical and Computer Engineering, Seoul National University, Seoul 151-744, Republic of Korea
| | - Daewoong Kwon
- Department of Electronic Engineering, Inha University, Incheon 22212, Republic of Korea
| | - Byung-Gook Park
- Inter-University Semiconductor Research Center, Department of Electrical and Computer Engineering, Seoul National University, Seoul 151-744, Republic of Korea
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6
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Chen L, Zhou J, Zhang X, Ding K, Ding J, Sun Z, Wang X. Low-Temperature Tunneling Electroresistance in Ferromagnetic Metal/Ferroelectric/Semiconductor Tunnel Junctions. ACS Appl Mater Interfaces 2021; 13:23282-23288. [PMID: 33944549 DOI: 10.1021/acsami.1c05366] [Citation(s) in RCA: 4] [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] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Ferroelectric tunnel junctions (FTJs) as artificial synaptic devices are promising candidates for the building block of nonvolatile data storage devices. However, a small ON/OFF ratio of FTJs limits their application in low-temperature operations. In this work, the influence of quantum interference effects on tunneling electroresistance in the La0.7Sr0.3MnO3/BaTiO3/Nb:SrTiO3 (ferromagnetic metal/ferroelectric/semiconductor) FTJ at low temperatures is investigated. The Current-voltage curves are observed in the tunnel junction from 300 to 10 K with a six-unit-cell thick BaTiO3 film by the ferroelectric polarization effect. First, the ON/OFF current ratio increases from 300 to 30 K due to the increase of polarization in the ferroelectric barrier, and then, it gradually decreases when the temperature drops below 30 K. An anomalous ON/OFF current ratio of ∼105 is obtained at 30 K. The low-temperature tunneling properties in the FTJ are associated with a low-temperature resistivity minimum in the ferromagnetic metal layer by the electron-electron interaction, which increases the La0.7Sr0.3MnO3/BaTiO3 interface resistance, leading to a higher resistance state and lower IOFF for the OFF state. As a result, the ON/OFF current ratio is abruptly enhanced at 30 K. Our results emphasize the crucial role of transport properties of La0.7Sr0.3MnO3 in FTJs and pave the way for the design and application of FTJs at low temperatures.
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Affiliation(s)
- Liming Chen
- School of Materials Science and Engineering, Anhui University of Technology, Ma'anshan, Anhui 243002, P. R. China
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, P. R. China
| | - Jian Zhou
- School of Materials Science and Engineering, Anhui University of Technology, Ma'anshan, Anhui 243002, P. R. China
| | - Xiao Zhang
- School of Materials Science and Engineering, Anhui University of Technology, Ma'anshan, Anhui 243002, P. R. China
| | - Kuankuan Ding
- School of Materials Science and Engineering, Anhui University of Technology, Ma'anshan, Anhui 243002, P. R. China
| | - Jianxiang Ding
- School of Materials Science and Engineering, Anhui University of Technology, Ma'anshan, Anhui 243002, P. R. China
- Jiangsu Key Laboratory of Advanced Metallic Materials, School of Materials Science and Engineering, Southeast University, Nanjing 211189, P. R. China
| | - Zhengming Sun
- School of Materials Science and Engineering, Anhui University of Technology, Ma'anshan, Anhui 243002, P. R. China
- Jiangsu Key Laboratory of Advanced Metallic Materials, School of Materials Science and Engineering, Southeast University, Nanjing 211189, P. R. China
| | - Xuefeng Wang
- Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, P. R. China
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7
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Yang Y, Xi Z, Dong Y, Zheng C, Hu H, Li X, Jiang Z, Lu WC, Wu D, Wen Z. Spin-Filtering Ferroelectric Tunnel Junctions as Multiferroic Synapses for Neuromorphic Computing. ACS Appl Mater Interfaces 2020; 12:56300-56309. [PMID: 33287535 DOI: 10.1021/acsami.0c16385] [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] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
As nanoelectronic synapses, memristive ferroelectric tunnel junctions (FTJs) have triggered great interest due to the potential applications in neuromorphic computing for emulating biological brains. Here, we demonstrate multiferroic FTJ synapses based on the ferroelectric modulation of spin-filtering BaTiO3/CoFe2O4 composite barriers. Continuous conductance change with an ON/OFF current ratio of ∼54 400% and long-term memory with the spike-timing-dependent plasticity (STDP) of synaptic weight for Hebbian learning are achieved by controlling the polarization switching of BaTiO3. Supervised learning simulations adopting the STDP results as database for weight training are performed on a crossbar neural network and exhibit a high accuracy rate above 97% for recognition. The polarization switching also alters the band alignment of CoFe2O4 barrier relative to the electrodes, giving rise to the change of tunneling magnetoresistance ratio by about 10 times and even the reversal of its sign depending upon the resistance states. These results, especially the electrically switchable spin polarization, provide a new approach toward multiferroic neuromorphic devices with energy-efficient electrical manipulations through potential barrier design. In addition, the availability of spinel ferrite barriers epitaxially grown with ferroelectric oxides also expends the playground of FTJ devices for a broad scope of applications.
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Affiliation(s)
- Yihao Yang
- College of Physics and Center for Marine Observation and Communications, Qingdao University, Qingdao 266071, China
| | - Zhongnan Xi
- National Laboratory of Solid State Microstructures, Department of Materials Science and Engineering, Jiangsu Key Laboratory of Artificial Functional Materials and Collaborative Innovation Center for Advanced Materials, Nanjing University, Nanjing 210093, China
| | - Yuehang Dong
- School of Data Science and Software Engineering, Qingdao University, Qingdao 266071, China
| | - Chunyan Zheng
- College of Physics and Center for Marine Observation and Communications, Qingdao University, Qingdao 266071, China
| | - Haihua Hu
- College of Physics and Center for Marine Observation and Communications, Qingdao University, Qingdao 266071, China
| | - Xiaofei Li
- College of Physics and Center for Marine Observation and Communications, Qingdao University, Qingdao 266071, China
| | - Zhizheng Jiang
- College of Physics and Center for Marine Observation and Communications, Qingdao University, Qingdao 266071, China
| | - Wen-Cai Lu
- College of Physics and Center for Marine Observation and Communications, Qingdao University, Qingdao 266071, China
| | - Di Wu
- National Laboratory of Solid State Microstructures, Department of Materials Science and Engineering, Jiangsu Key Laboratory of Artificial Functional Materials and Collaborative Innovation Center for Advanced Materials, Nanjing University, Nanjing 210093, China
| | - Zheng Wen
- College of Physics and Center for Marine Observation and Communications, Qingdao University, Qingdao 266071, China
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8
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Yang Y, Wu M, Li X, Hu H, Jiang Z, Li Z, Hao X, Zheng C, Lou X, Pennycook SJ, Wen Z. The Role of Ferroelectric Polarization in Resistive Memory Properties of Metal/Insulator/Semiconductor Tunnel Junctions: A Comparative Study. ACS Appl Mater Interfaces 2020; 12:32935-32942. [PMID: 32588626 DOI: 10.1021/acsami.0c08708] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Recently, tunnel junction devices adopting semiconducting Nb:SrTiO3 electrodes have attracted considerable attention for their potential applications in resistive data storage and neuromorphic computing. In this work, we report on a comparative study of Pt/insulator/Nb:SrTiO3 tunnel junctions between ferroelectric BaTiO3 and nonferroelectric SrTiO3 and LaAlO3 barriers to reveal the role of polarization in resistance switching properties. Although hysteretic behaviors appear in current-voltage measurements of all devices regardless of the barrier character, significantly improved current ratios by more than three orders of magnitude are observed in the Pt/BaTiO3/Nb:SrTiO3 tunnel junctions due to the dominance of polarization in modulation of junction barrier profiles between the low and high resistance states. The switchable polarization also gives rise to enhanced resistance retention since the electron diffusion that smears the barrier contrast of the bistable resistance states is suppressed by the polar BaTiO3/Nb:SrTiO3 interface associated with the ferroelectric bound charges. These polarization-induced effects are absent in the nonferroelectric Pt/SrTiO3/Nb:SrTiO3 and Pt/LaAlO3/Nb:SrTiO3 devices in which serious resistance state decay, described by Fick's second law, is observed since there are no switchable interface charges on SrTiO3/Nb:SrTiO3 and LaAlO3/Nb:SrTiO3 to block the electron diffusion. In addition, the Pt/BaTiO3/Nb:SrTiO3 device also exhibits an excellent switching endurance up to ∼4.0 × 106 bipolar cycles. These enhancements indicate the importance of ferroelectric polarization for achieving high-performance resistance switching and suggest that metal/ferroelectric/Nb:SrTiO3 tunnel junctions are promising candidates for nonvolatile memory applications.
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Affiliation(s)
- Yihao Yang
- College of Physics and Center for Marine Observation and Communications, Qingdao University, Qingdao 266071, China
| | - Ming Wu
- Department of Materials Science and Engineering, National University of Singapore, Singapore 117575
- Frontier Institute of Science and Technology, and State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China
| | - Xiaofei Li
- College of Physics and Center for Marine Observation and Communications, Qingdao University, Qingdao 266071, China
| | - Haihua Hu
- College of Physics and Center for Marine Observation and Communications, Qingdao University, Qingdao 266071, China
| | - Zhizheng Jiang
- College of Physics and Center for Marine Observation and Communications, Qingdao University, Qingdao 266071, China
| | - Zhen Li
- College of Physics and Center for Marine Observation and Communications, Qingdao University, Qingdao 266071, China
| | - Xintai Hao
- College of Physics and Center for Marine Observation and Communications, Qingdao University, Qingdao 266071, China
| | - Chunyan Zheng
- College of Physics and Center for Marine Observation and Communications, Qingdao University, Qingdao 266071, China
| | - Xiaojie Lou
- Frontier Institute of Science and Technology, and State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China
| | - Stephen J Pennycook
- Department of Materials Science and Engineering, National University of Singapore, Singapore 117575
| | - Zheng Wen
- College of Physics and Center for Marine Observation and Communications, Qingdao University, Qingdao 266071, China
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9
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Abstract
Recently, ferroelectric tunnel junctions (FTJs) have attracted considerable attention for potential applications in next-generation memories, owing to attractive advantages such as high-density of data storage, nondestructive readout, fast write/read access, and low energy consumption. Herein, recent progress regarding FTJ devices is reviewed with an emphasis on the modulation of the potential barrier. Electronic and ionic approaches that modulate the ferroelectric barriers themselves and/or induce extra barriers in electrodes or at ferroelectric/electrode interfaces are discussed with the enhancement of memory performance. Emerging physics, such as nanoscale ferroelectricity, resonant tunneling, and interfacial metallization, and the applications of FTJs in nonvolatile data storage, neuromorphic synapse emulation, and electromagnetic multistate memory are summarized. Finally, challenges and perspectives of FTJ devices are underlined.
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Affiliation(s)
- Zheng Wen
- College of Physics and Center for Marine Observation and Communications, Qingdao University, Qingdao, 266071, China
- Collaborative Innovation Center for Advanced Materials, Nanjing University, Nanjing, 210093, China
| | - Di Wu
- National Laboratory of Solid State Microstructures, Department of Materials Science and Engineering, Jiangsu Key Laboratory of Artificial Functional Materials and Collaborative Innovation Center for Advanced Materials, Nanjing University, Nanjing, 210093, China
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10
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Li J, Ge C, Du J, Wang C, Yang G, Jin K. Reproducible Ultrathin Ferroelectric Domain Switching for High-Performance Neuromorphic Computing. Adv Mater 2020; 32:e1905764. [PMID: 31850652 DOI: 10.1002/adma.201905764] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 11/19/2019] [Indexed: 05/22/2023]
Abstract
Neuromorphic computing consisting of artificial synapses and neural network algorithms provides a promising approach for overcoming the inherent limitations of current computing architecture. Developments in electronic devices that can accurately mimic the synaptic plasticity of biological synapses, have promoted the research boom of neuromorphic computing. It is reported that robust ferroelectric tunnel junctions can be employed to design high-performance electronic synapses. These devices show an excellent memristor function with many reproducible states (≈200) through gradual ferroelectric domain switching. Both short- and long-term plasticity can be emulated by finely tuning the applied pulse parameters in the electronic synapse. The analog conductance switching exhibits high linearity and symmetry with small switching variations. A simulated artificial neural network with supervised learning built from these synaptic devices exhibited high classification accuracy (96.4%) for the Mixed National Institute of Standards and Technology (MNIST) handwritten recognition data set.
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Affiliation(s)
- Jiankun Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Chen Ge
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Key Laboratory of Polar Materials and Devices, Ministry of Education, Shanghai, 200241, China
| | - Jianyu Du
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Can Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China
| | - Guozhen Yang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Kuijuan Jin
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong, 523808, China
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11
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Abstract
Crystalline oxide ferroelectric tunnel junctions enable persistent encoding of information in electric polarization, featuring nondestructive readout and scalability that can exceed current commercial high-speed, nonvolatile ferroelectric memories. However, the well-established fabrication of epitaxial devices on oxide substrates is difficult to adapt to silicon substrates for integration into complementary metal-oxide-semiconductor electronics. In this work, we report ferroelectric tunnel junctions based on 2.8 nm-thick BaTiO3 films grown epitaxially on SrTiO3 growth substrates, released, and relaminated onto silicon. The performance of the transferred devices is comparable to devices characterized on the oxide substrate, suggesting a viable route toward next-generation nonvolatile memories broadly integrable with different materials platforms.
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Affiliation(s)
- Di Lu
- Department of Physics , Stanford University , Stanford , California 94305 , United States
| | - Sam Crossley
- Department of Applied Physics , Stanford University , Stanford , California 94305 , United States
| | - Ruijuan Xu
- Department of Applied Physics , Stanford University , Stanford , California 94305 , United States
- Stanford Institute for Materials and Energy Sciences , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
| | - Yasuyuki Hikita
- Stanford Institute for Materials and Energy Sciences , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
| | - Harold Y Hwang
- Department of Applied Physics , Stanford University , Stanford , California 94305 , United States
- Stanford Institute for Materials and Energy Sciences , SLAC National Accelerator Laboratory , Menlo Park , California 94025 , United States
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12
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Qian M, Fina I, Sánchez F, Fontcuberta J. Complementary Resistive Switching Using Metal-Ferroelectric-Metal Tunnel Junctions. Small 2019; 15:e1805042. [PMID: 30740894 DOI: 10.1002/smll.201805042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 01/17/2019] [Indexed: 06/09/2023]
Abstract
Complementary resistive switching (CRS) devices are receiving attention because they can potentially solve the current-sneak and current-leakage problems of memory arrays based on resistive switching (RS) elements. It is shown here that a simple anti-serial connection of two ferroelectric tunnel junctions, based on BaTiO3 , with symmetric top metallic electrodes and a common, floating bottom nanometric film electrode, constitute a CRS memory element. It allows nonvolatile storage of binary states ("1" = "HRS+LRS" and "0" = "LRS+HRS"), where HRS (LRS) indicate the high (low) resistance state of each ferroelectric tunnel junction. Remarkably, these states have an identical and large resistance in the remanent state, characteristic of CRS. Here, protocols for writing information are reported and it is shown that non-destructive or destructive reading schemes can be chosen by selecting the appropriate reading voltage amplitude. Moreover, this dual-tunnel device has a significantly lower power consumption than a single ferroelectric tunnel junction to perform writing/reading functions, as is experimentally demonstrated. These findings illustrate that the recent impressive development of ferroelectric tunnel junctions can be further exploited to contribute to solving critical bottlenecks in data storage and logic functions implemented using RS elements.
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Affiliation(s)
- Mengdi Qian
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, Bellaterra, 08193, Catalonia, Spain
| | - Ignasi Fina
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, Bellaterra, 08193, Catalonia, Spain
| | - Florencio Sánchez
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, Bellaterra, 08193, Catalonia, Spain
| | - Josep Fontcuberta
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, Bellaterra, 08193, Catalonia, Spain
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13
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Guo R, Zhou Y, Wu L, Wang Z, Lim Z, Yan X, Lin W, Wang H, Yoong HY, Chen S, Venkatesan T, Wang J, Chow GM, Gruverman A, Miao X, Zhu Y, Chen J. Control of Synaptic Plasticity Learning of Ferroelectric Tunnel Memristor by Nanoscale Interface Engineering. ACS Appl Mater Interfaces 2018; 10:12862-12869. [PMID: 29617112 DOI: 10.1021/acsami.8b01469] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Brain-inspired computing is an emerging field, which intends to extend the capabilities of information technology beyond digital logic. The progress of the field relies on artificial synaptic devices as the building block for brainlike computing systems. Here, we report an electronic synapse based on a ferroelectric tunnel memristor, where its synaptic plasticity learning property can be controlled by nanoscale interface engineering. The effect of the interface engineering on the device performance was studied. Different memristor interfaces lead to an opposite virgin resistance state of the devices. More importantly, nanoscale interface engineering could tune the intrinsic band alignment of the ferroelectric/metal-semiconductor heterostructure over a large range of 1.28 eV, which eventually results in different memristive and spike-timing-dependent plasticity (STDP) properties of the devices. Bidirectional and unidirectional gradual resistance modulation of the devices could therefore be controlled by tuning the band alignment. This study gives useful insights on tuning device functionalities through nanoscale interface engineering. The diverse STDP forms of the memristors with different interfaces may play different specific roles in various spike neural networks.
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Affiliation(s)
- Rui Guo
- Department of Materials Science and Engineering , National University of Singapore , 117575 , Singapore
- NUSNNI-Nanocore , National University of Singapore , 117411 , Singapore
| | - Yaxiong Zhou
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Lijun Wu
- Condensed Matter Physics & Materials Science Division, Brookhaven National Laboratory , Upton, New York , New York 11973 , United States
| | - Zhuorui Wang
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Zhishiuh Lim
- NUSNNI-Nanocore , National University of Singapore , 117411 , Singapore
| | - Xiaobing Yan
- Department of Materials Science and Engineering , National University of Singapore , 117575 , Singapore
| | - Weinan Lin
- Department of Materials Science and Engineering , National University of Singapore , 117575 , Singapore
| | - Han Wang
- Department of Materials Science and Engineering , National University of Singapore , 117575 , Singapore
| | - Herng Yau Yoong
- Department of Materials Science and Engineering , National University of Singapore , 117575 , Singapore
| | - Shaohai Chen
- Department of Materials Science and Engineering , National University of Singapore , 117575 , Singapore
| | - Thirumalai Venkatesan
- Department of Materials Science and Engineering , National University of Singapore , 117575 , Singapore
- NUSNNI-Nanocore , National University of Singapore , 117411 , Singapore
- Department of Physics , National University of Singapore , 117542 , Singapore
- Department of Electrical and Computer Engineering , National University of Singapore , 117583 , Singapore
| | - John Wang
- Department of Materials Science and Engineering , National University of Singapore , 117575 , Singapore
| | - Gan Moog Chow
- Department of Materials Science and Engineering , National University of Singapore , 117575 , Singapore
| | - Alexei Gruverman
- Department of Physics and Astronomy , University of Nebraska-Lincoln , Lincoln , Nebraska 68588 , United States
| | - Xiangshui Miao
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information , Huazhong University of Science and Technology , Wuhan 430074 , China
| | - Yimei Zhu
- Condensed Matter Physics & Materials Science Division, Brookhaven National Laboratory , Upton, New York , New York 11973 , United States
| | - Jingsheng Chen
- Department of Materials Science and Engineering , National University of Singapore , 117575 , Singapore
- NUSNNI-Nanocore , National University of Singapore , 117411 , Singapore
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14
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Matveyev Y, Negrov D, Chernikova A, Lebedinskii Y, Kirtaev R, Zarubin S, Suvorova E, Gloskovskii A, Zenkevich A. Effect of Polarization Reversal in Ferroelectric TiN/Hf 0.5Zr 0.5O 2/TiN Devices on Electronic Conditions at Interfaces Studied in Operando by Hard X-ray Photoemission Spectroscopy. ACS Appl Mater Interfaces 2017; 9:43370-43376. [PMID: 29160064 DOI: 10.1021/acsami.7b14369] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Because of their compatibility with modern Si-based technology, HfO2-based ferroelectric films have recently attracted attention as strong candidates for applications in memory devices, in particular, ferroelectric field-effect transistors or ferroelectric tunnel junctions. A key property defining the functionality of these devices is the polarization dependent change of the electronic band alignment at the metal/ferroelectric interface. Here, we report on the effect of polarization reversal in functional ferroelectric TiN/Hf0.5Zr0.5O2/TiN capacitors on the potential distribution across the stack and the electronic band line-up at the interfaces studied in operando by hard X-ray photoemission spectroscopy. By tracking changes in the position of Hf0.5Zr0.5O2 core-level lines with respect to those of the TiN electrode in both short- and open-circuit configurations following in situ polarization reversal, we derive the conduction band offset to be 0.7 (1.0) eV at the top and 1.7 (1.0) eV at the bottom interfaces for polarization, pointing up (down), respectively. Energy dispersive X-ray spectroscopy profiling of the sample cross-section in combination with the laboratory X-ray photoelectron spectroscopy reveal the presence of a TiOx/TiON layer at both interfaces. The observed asymmetry in the band line-up changes in the TiN/Hf0.5Zr0.5O2/TiN memory stack is explained by different origin of these oxidized layers and effective pinning of polarization at the top interface. The described methodology and first experimental results are useful for the optimization of HfO2-based ferroelectric memory devices under development.
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Affiliation(s)
- Yury Matveyev
- Moscow Institute of Physics and Technology , 9, Institutskiy Lane, Dolgoprudny, Moscow region, 141701, Russia
| | - Dmitry Negrov
- Moscow Institute of Physics and Technology , 9, Institutskiy Lane, Dolgoprudny, Moscow region, 141701, Russia
| | - Anna Chernikova
- Moscow Institute of Physics and Technology , 9, Institutskiy Lane, Dolgoprudny, Moscow region, 141701, Russia
| | - Yury Lebedinskii
- Moscow Institute of Physics and Technology , 9, Institutskiy Lane, Dolgoprudny, Moscow region, 141701, Russia
| | - Roman Kirtaev
- Moscow Institute of Physics and Technology , 9, Institutskiy Lane, Dolgoprudny, Moscow region, 141701, Russia
| | - Sergei Zarubin
- Moscow Institute of Physics and Technology , 9, Institutskiy Lane, Dolgoprudny, Moscow region, 141701, Russia
| | - Elena Suvorova
- Moscow Institute of Physics and Technology , 9, Institutskiy Lane, Dolgoprudny, Moscow region, 141701, Russia
- A.V. Shubnikov Institute of Crystallography , Leninsky pr. 59, Moscow 119333, Russia
| | - Andrei Gloskovskii
- Deutsches Elektronen-Synchrotron , 85 Notkestraße, Hamburg D-22607, Germany
| | - Andrei Zenkevich
- Moscow Institute of Physics and Technology , 9, Institutskiy Lane, Dolgoprudny, Moscow region, 141701, Russia
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15
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Lü W, Li C, Zheng L, Xiao J, Lin W, Li Q, Wang XR, Huang Z, Zeng S, Han K, Zhou W, Zeng K, Chen J, Cao W, Venkatesan T. Multi-Nonvolatile State Resistive Switching Arising from Ferroelectricity and Oxygen Vacancy Migration. Adv Mater 2017; 29:1606165. [PMID: 28439926 DOI: 10.1002/adma.201606165] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 03/18/2017] [Indexed: 06/07/2023]
Abstract
Resistive switching phenomena form the basis of competing memory technologies. Among them, resistive switching, originating from oxygen vacancy migration (OVM), and ferroelectric switching offer two promising approaches. OVM in oxide films/heterostructures can exhibit high/low resistive state via conducting filament forming/deforming, while the resistive switching of ferroelectric tunnel junctions (FTJs) arises from barrier height or width variation while ferroelectric polarization reverses between asymmetric electrodes. Here the authors demonstrate a coexistence of OVM and ferroelectric induced resistive switching in a BaTiO3 FTJ by comparing BaTiO3 with SrTiO3 based tunnel junctions. This coexistence results in two distinguishable loops with multi-nonvolatile resistive states. The primary loop originates from the ferroelectric switching. The second loop emerges at a voltage close to the SrTiO3 switching voltage, showing OVM being its origin. BaTiO3 based devices with controlled oxygen vacancies enable us to combine the benefits of both OVM and ferroelectric tunneling to produce multistate nonvolatile memory devices.
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Affiliation(s)
- Weiming Lü
- Condensed Matter Science and Technology Institute, Department of Physics, Harbin Institute of Technology, Harbin, 150001, China
| | - Changjian Li
- Department of Material Science & Engineering, National University of Singapore, Singapore, 117575, Singapore
- NUSNNI-Nanocore, National University of Singapore, Singapore, 117411, Singapore
| | - Limei Zheng
- Condensed Matter Science and Technology Institute, Department of Physics, Harbin Institute of Technology, Harbin, 150001, China
| | - Juanxiu Xiao
- Department of Material Science & Engineering, National University of Singapore, Singapore, 117575, Singapore
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, 570228, China
- Department of Mechanical Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Weinan Lin
- Department of Material Science & Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Qiang Li
- Condensed Matter Science and Technology Institute, Department of Physics, Harbin Institute of Technology, Harbin, 150001, China
| | - Xiao Renshaw Wang
- School of Physical and Mathematical Sciences & School of Electrical and Electronic Engineering, Nayang Technological University, Singapore, 637371, Singapore
| | - Zhen Huang
- NUSNNI-Nanocore, National University of Singapore, Singapore, 117411, Singapore
| | - Shengwei Zeng
- NUSNNI-Nanocore, National University of Singapore, Singapore, 117411, Singapore
| | - Kun Han
- NUSNNI-Nanocore, National University of Singapore, Singapore, 117411, Singapore
- Department of Physics, National University of Singapore, Singapore, 117571, Singapore
| | - Wenxiong Zhou
- NUSNNI-Nanocore, National University of Singapore, Singapore, 117411, Singapore
- Department of Physics, National University of Singapore, Singapore, 117571, Singapore
| | - Kaiyang Zeng
- Department of Mechanical Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Jingsheng Chen
- Department of Material Science & Engineering, National University of Singapore, Singapore, 117575, Singapore
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore, 117456, Singapore
| | - Wenwu Cao
- Condensed Matter Science and Technology Institute, Department of Physics, Harbin Institute of Technology, Harbin, 150001, China
| | - Thirumalai Venkatesan
- Department of Material Science & Engineering, National University of Singapore, Singapore, 117575, Singapore
- NUSNNI-Nanocore, National University of Singapore, Singapore, 117411, Singapore
- Department of Physics, National University of Singapore, Singapore, 117571, Singapore
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore, 117456, Singapore
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore
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16
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Ambriz-Vargas F, Kolhatkar G, Broyer M, Hadj-Youssef A, Nouar R, Sarkissian A, Thomas R, Gomez-Yáñez C, Gauthier MA, Ruediger A. A Complementary Metal Oxide Semiconductor Process-Compatible Ferroelectric Tunnel Junction. ACS Appl Mater Interfaces 2017; 9:13262-13268. [PMID: 28368099 DOI: 10.1021/acsami.6b16173] [Citation(s) in RCA: 9] [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] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In recent years, experimental demonstration of ferroelectric tunnel junctions (FTJ) based on perovskite tunnel barriers has been reported. However, integrating these perovskite materials into conventional silicon memory technology remains challenging due to their lack of compatibility with the complementary metal oxide semiconductor process (CMOS). This communication reports the fabrication of an FTJ based on a CMOS-compatible tunnel barrier Hf0.5Zr0.5O2 (6 unit cells thick) on an equally CMOS-compatible TiN electrode. Analysis of the FTJ by grazing angle incidence X-ray diffraction confirmed the formation of the noncentrosymmetric orthorhombic phase (Pbc21, ferroelectric phase). The FTJ characterization is followed by the reconstruction of the electrostatic potential profile in the as-grown TiN/Hf0.5Zr0.5O2/Pt heterostructure. A direct tunneling current model across a trapezoidal barrier was used to correlate the electronic and electrical properties of our FTJ devices. The good agreement between the experimental and theoretical model attests to the tunneling electroresistance effect (TER) in our FTJ device. A TER ratio of ∼15 was calculated for the present FTJ device at low read voltage (+0.2 V). This study suggests that Hf0.5Zr0.5O2 is a promising candidate for integration into conventional Si memory technology.
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Affiliation(s)
- Fabian Ambriz-Vargas
- Centre Énergie, Matériaux et Télécommunications, INRS , Varennes, Québec J3X1S2, Canada
| | - Gitanjali Kolhatkar
- Centre Énergie, Matériaux et Télécommunications, INRS , Varennes, Québec J3X1S2, Canada
| | - Maxime Broyer
- Centre Énergie, Matériaux et Télécommunications, INRS , Varennes, Québec J3X1S2, Canada
| | - Azza Hadj-Youssef
- Centre Énergie, Matériaux et Télécommunications, INRS , Varennes, Québec J3X1S2, Canada
| | - Rafik Nouar
- Plasmionique Inc. , 9092 Rimouski, Brossard, Québec J4X2S3, Canada
| | | | - Reji Thomas
- Centre Énergie, Matériaux et Télécommunications, INRS , Varennes, Québec J3X1S2, Canada
| | - Carlos Gomez-Yáñez
- Departamento de Ingeniería en Metalurgia y Materiales, Instituto Politécnico Nacional , Zacatenco 07738, México
| | - Marc A Gauthier
- Centre Énergie, Matériaux et Télécommunications, INRS , Varennes, Québec J3X1S2, Canada
| | - Andreas Ruediger
- Centre Énergie, Matériaux et Télécommunications, INRS , Varennes, Québec J3X1S2, Canada
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17
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Guo R, Wang Y, Yoong HY, Chai J, Wang H, Lin W, Chen S, Yan X, Venkatesan T, Gruverman A, Wu Y, Chen J. Effect of Extrinsically Introduced Passive Interface Layer on the Performance of Ferroelectric Tunnel Junctions. ACS Appl Mater Interfaces 2017; 9:5050-5055. [PMID: 28165212 DOI: 10.1021/acsami.6b15564] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We report the effect of the top electrode/functional layer interface on the performance of ferroelectric tunnel junctions. Ex situ and in situ fabrication process were used to fabricate the top Pt electrode. With the ex situ fabrication process, one passive layer at the top interface would be induced. Our experimental results show that the passive interface layer of the ex situ devices increases the coercive voltage of the functional BaTiO3 layer and decreases the tunneling current magnitude. However, the ex situ tunneling devices possess more than 1000 times larger ON/OFF ratios than that of the in situ devices with the same size of top electrode.
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Affiliation(s)
- Rui Guo
- Department of Materials Science and Engineering, National University of Singapore , 117575 Singapore
- NUSNNI-Nanocore, National University of Singapore , 117411 Singapore
| | - Ying Wang
- Department of Electrical and Computer Engineering, National University of Singapore , 117583 Singapore
| | - Herng Yau Yoong
- Department of Materials Science and Engineering, National University of Singapore , 117575 Singapore
| | - Jianwei Chai
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR) , 2 Fusionopolis Way #08-01 Innovis, 138634 Singapore
| | - Han Wang
- Department of Materials Science and Engineering, National University of Singapore , 117575 Singapore
| | - Weinan Lin
- Department of Materials Science and Engineering, National University of Singapore , 117575 Singapore
| | - Shaohai Chen
- Department of Materials Science and Engineering, National University of Singapore , 117575 Singapore
| | - Xiaobing Yan
- Department of Materials Science and Engineering, National University of Singapore , 117575 Singapore
| | - Thirumalai Venkatesan
- Department of Materials Science and Engineering, National University of Singapore , 117575 Singapore
- NUSNNI-Nanocore, National University of Singapore , 117411 Singapore
- Department of Electrical and Computer Engineering, National University of Singapore , 117583 Singapore
- Department of Physics, National University of Singapore , 117542 Singapore
- NUS Graduate School for Integrative Science and Engineering, National University of Singapore , 117576 Singapore
| | - Alexei Gruverman
- Department of Physics and Astronomy and Nebraska Center for Materials and Nanoscience, University of Nebraska , Lincoln, Nebraska 68588-0299, United States
| | - Yihong Wu
- Department of Electrical and Computer Engineering, National University of Singapore , 117583 Singapore
| | - Jingsheng Chen
- Department of Materials Science and Engineering, National University of Singapore , 117575 Singapore
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18
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Li T, Sharma P, Lipatov A, Lee H, Lee JW, Zhuravlev MY, Paudel TR, Genenko YA, Eom CB, Tsymbal EY, Sinitskii A, Gruverman A. Polarization-Mediated Modulation of Electronic and Transport Properties of Hybrid MoS 2-BaTiO 3-SrRuO 3 Tunnel Junctions. Nano Lett 2017; 17:922-927. [PMID: 28094991 DOI: 10.1021/acs.nanolett.6b04247] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Hybrid structures composed of ferroelectric thin films and functional two-dimensional (2D) materials may exhibit unique characteristics and reveal new phenomena due to the cross-interface coupling between their intrinsic properties. In this report, we demonstrate a symbiotic interplay between spontaneous polarization of the ultrathin BaTiO3 ferroelectric film and conductivity of the adjacent molybdenum disulfide (MoS2) layer, a 2D narrow-bandgap semiconductor. Polarization-induced modulation of the electronic properties of MoS2 results in a giant tunneling electroresistance effect in the hybrid MoS2-BaTiO3-SrRuO3 ferroelectric tunnel junctions (FTJs) with an OFF-to-ON resistance ratio as high as 104, a 50-fold increase in comparison with the same type of FTJs with metal electrodes. The effect stems from the reversible accumulation-depletion of the majority carriers in the MoS2 electrode in response to ferroelectric switching, which alters the barrier at the MoS2-BaTiO3 interface. Continuous tunability of resistive states realized via stable sequential domain structures in BaTiO3 adds memristive functionality to the hybrid FTJs. The use of narrow band 2D semiconductors in conjunction with ferroelectric films provides a novel pathway for development of the electronic devices with enhanced performance.
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Affiliation(s)
| | | | | | - Hyungwoo Lee
- Materials Science and Engineering, University of Wisconsin , Madison, Wisconsin 53706, United States
| | - Jung-Woo Lee
- Materials Science and Engineering, University of Wisconsin , Madison, Wisconsin 53706, United States
| | - Mikhail Y Zhuravlev
- Kurnakov Institute for General and Inorganic Chemistry, Russian Academy of Sciences , 119991 Moscow, Russia
- Saint Petersburg State University , 190000 St. Petersburg, Russia
| | | | - Yuri A Genenko
- Institute of Materials Science, Technische Universität Darmstadt , D-64287 Darmstadt, Germany
| | - Chang-Beom Eom
- Materials Science and Engineering, University of Wisconsin , Madison, Wisconsin 53706, United States
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19
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Qin QH, Äkäslompolo L, Tuomisto N, Yao L, Majumdar S, Vijayakumar J, Casiraghi A, Inkinen S, Chen B, Zugarramurdi A, Puska M, van Dijken S. Resistive Switching in All-Oxide Ferroelectric Tunnel Junctions with Ionic Interfaces. Adv Mater 2016; 28:6852-6859. [PMID: 27248832 DOI: 10.1002/adma.201504519] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 02/03/2016] [Indexed: 06/05/2023]
Abstract
Universal, giant and nonvolatile resistive switching is demonstrated for oxide tunnel junctions with ferroelectric PbZr0.2 Ti0.8 O3 , ferroelectric BaTiO3, and paraelectric SrTiO3 tunnel barriers. The effects are caused by reversible migration of oxygen vacancies between the tunnel barrier and bottom La2/3 Sr1/3 MnO3 electrode. The switching process, which is driven by large electric fields, is efficient down to a temperature of 5 K.
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Affiliation(s)
- Qi Hang Qin
- NanoSpin, Department of Applied Physics, Aalto University School of Science, P.O. Box, 15100, FI-00076, Aalto, Finland
| | - Laura Äkäslompolo
- NanoSpin, Department of Applied Physics, Aalto University School of Science, P.O. Box, 15100, FI-00076, Aalto, Finland
| | - Noora Tuomisto
- COMP Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 11100, FI-00076, Aalto, Finland
| | - Lide Yao
- NanoSpin, Department of Applied Physics, Aalto University School of Science, P.O. Box, 15100, FI-00076, Aalto, Finland
| | - Sayani Majumdar
- NanoSpin, Department of Applied Physics, Aalto University School of Science, P.O. Box, 15100, FI-00076, Aalto, Finland
| | - Jaianth Vijayakumar
- NanoSpin, Department of Applied Physics, Aalto University School of Science, P.O. Box, 15100, FI-00076, Aalto, Finland
| | - Arianna Casiraghi
- NanoSpin, Department of Applied Physics, Aalto University School of Science, P.O. Box, 15100, FI-00076, Aalto, Finland
| | - Sampo Inkinen
- NanoSpin, Department of Applied Physics, Aalto University School of Science, P.O. Box, 15100, FI-00076, Aalto, Finland
| | - Binbin Chen
- NanoSpin, Department of Applied Physics, Aalto University School of Science, P.O. Box, 15100, FI-00076, Aalto, Finland
| | - Asier Zugarramurdi
- COMP Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 11100, FI-00076, Aalto, Finland
| | - Martti Puska
- COMP Centre of Excellence, Department of Applied Physics, Aalto University, P.O. Box 11100, FI-00076, Aalto, Finland
| | - Sebastiaan van Dijken
- NanoSpin, Department of Applied Physics, Aalto University School of Science, P.O. Box, 15100, FI-00076, Aalto, Finland
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20
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Lee H, Kim TH, Patzner JJ, Lu H, Lee JW, Zhou H, Chang W, Mahanthappa MK, Tsymbal EY, Gruverman A, Eom CB. Imprint Control of BaTiO3 Thin Films via Chemically Induced Surface Polarization Pinning. Nano Lett 2016; 16:2400-6. [PMID: 26901570 DOI: 10.1021/acs.nanolett.5b05188] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Surface-adsorbed polar molecules can significantly alter the ferroelectric properties of oxide thin films. Thus, fundamental understanding and controlling the effect of surface adsorbates are crucial for the implementation of ferroelectric thin film devices, such as ferroelectric tunnel junctions. Herein, we report an imprint control of BaTiO3 (BTO) thin films by chemically induced surface polarization pinning in the top few atomic layers of the water-exposed BTO films. Our studies based on synchrotron X-ray scattering and coherent Bragg rod analysis demonstrate that the chemically induced surface polarization is not switchable but reduces the polarization imprint and improves the bistability of ferroelectric phase in BTO tunnel junctions. We conclude that the chemical treatment of ferroelectric thin films with polar molecules may serve as a simple yet powerful strategy to enhance functional properties of ferroelectric tunnel junctions for their practical applications.
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Affiliation(s)
- Hyungwoo Lee
- Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Tae Heon Kim
- Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Jacob J Patzner
- Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Haidong Lu
- Department of Physics and Astronomy, Nebraska Center for Materials and Nanoscience, University of Nebraska , Lincoln, Nebraska 68588, United States
| | - Jung-Woo Lee
- Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Hua Zhou
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory , Argonne, Illinois 60439, United States
| | - Wansoo Chang
- Department of Chemistry, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Mahesh K Mahanthappa
- Department of Chemistry, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
| | - Evgeny Y Tsymbal
- Department of Physics and Astronomy, Nebraska Center for Materials and Nanoscience, University of Nebraska , Lincoln, Nebraska 68588, United States
| | - Alexei Gruverman
- Department of Physics and Astronomy, Nebraska Center for Materials and Nanoscience, University of Nebraska , Lincoln, Nebraska 68588, United States
| | - Chang-Beom Eom
- Department of Materials Science and Engineering, University of Wisconsin-Madison , Madison, Wisconsin 53706, United States
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21
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Chernikova A, Kozodaev M, Markeev A, Negrov D, Spiridonov M, Zarubin S, Bak O, Buragohain P, Lu H, Suvorova E, Gruverman A, Zenkevich A. Ultrathin Hf0.5Zr0.5O2 Ferroelectric Films on Si. ACS Appl Mater Interfaces 2016; 8:7232-7. [PMID: 26931409 DOI: 10.1021/acsami.5b11653] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Because of their immense scalability and manufacturability potential, the HfO2-based ferroelectric films attract significant attention as strong candidates for application in ferroelectric memories and related electronic devices. Here, we report the ferroelectric behavior of ultrathin Hf0.5Zr0.5O2 films, with the thickness of just 2.5 nm, which makes them suitable for use in ferroelectric tunnel junctions, thereby further expanding the area of their practical application. Transmission electron microscopy and electron diffraction analysis of the films grown on highly doped Si substrates confirms formation of the fully crystalline non-centrosymmetric orthorhombic phase responsible for ferroelectricity in Hf0.5Zr0.5O2. Piezoresponse force microscopy and pulsed switching testing performed on the deposited top TiN electrodes provide further evidence of the ferroelectric behavior of the Hf0.5Zr0.5O2 films. The electronic band lineup at the top TiN/Hf0.5Zr0.5O2 interface and band bending at the adjacent n(+)-Si bottom layer attributed to the polarization charges in Hf0.5Zr0.5O2 have been determined using in situ X-ray photoelectron spectroscopy analysis. The obtained results represent a significant step toward the experimental implementation of Si-based ferroelectric tunnel junctions.
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Affiliation(s)
- Anna Chernikova
- Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700, Russia
| | - Maksim Kozodaev
- Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700, Russia
| | - Andrei Markeev
- Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700, Russia
| | - Dmitrii Negrov
- Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700, Russia
| | - Maksim Spiridonov
- Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700, Russia
| | - Sergei Zarubin
- Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700, Russia
| | - Ohheum Bak
- Department of Physics and Astronomy, University of Nebraska , Lincoln, Nebraska 68588-0299, United States
| | - Pratyush Buragohain
- Department of Physics and Astronomy, University of Nebraska , Lincoln, Nebraska 68588-0299, United States
| | - Haidong Lu
- Department of Physics and Astronomy, University of Nebraska , Lincoln, Nebraska 68588-0299, United States
| | - Elena Suvorova
- Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700, Russia
- École Polytechnique Fédérale de Lausanne, Lausanne, CH-1015, Switzerland
- A.V. Shubnikov Institute of Crystallography, Leninsky pr. 59, Moscow 119333, Russia
| | - Alexei Gruverman
- Department of Physics and Astronomy, University of Nebraska , Lincoln, Nebraska 68588-0299, United States
| | - Andrei Zenkevich
- Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region 141700, Russia
- NRNU "Moscow Engineering Physics Institute", Moscow 115409, Russia
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22
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Li C, Huang L, Li T, Lü W, Qiu X, Huang Z, Liu Z, Zeng S, Guo R, Zhao Y, Zeng K, Coey M, Chen J, Venkatesan T. Ultrathin BaTiO₃-based ferroelectric tunnel junctions through interface engineering. Nano Lett 2015; 15:2568-2573. [PMID: 25800535 DOI: 10.1021/acs.nanolett.5b00138] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The ability to change states using voltage in ferroelectric tunnel junctions (FTJs) offers a route for lowering the switching energy of memories. Enhanced tunneling electroresistance in FTJ can be achieved by asymmetric electrodes or introducing metal-insulator transition interlayers. However, a fundamental understanding of the role of each interface in a FTJ is lacking and compatibility with integrated circuits has not been explored adequately. Here, we report an incisive study of FTJ performance with varying asymmetry of the electrode/ferroelectric interfaces. Surprisingly high TER (∼400%) can be achieved at BaTiO3 layer thicknesses down to two unit cells (∼0.8 nm). Further our results prove that band offsets at each interface in the FTJs control the TER ratio. It is found that the off state resistance (R(Off)) increases much more rapidly with the number of interfaces compared to the on state resistance (ROn). These results are promising for future low energy memories.
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Affiliation(s)
- Changjian Li
- †NUSNNI-Nanocore, National University of Singapore, Singapore 117411, Singapore
- ‡National University of Singapore Graduate School for Integrative Sciences and Engineering (NGS), 28 Medical Drive, Singapore 117456, Singapore
| | | | - Tao Li
- ∥Department of Mechanical Engineering, National University of Singapore, Singapore 117575, Singapore
| | - Weiming Lü
- †NUSNNI-Nanocore, National University of Singapore, Singapore 117411, Singapore
| | - Xuepeng Qiu
- ⊥Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576, Singapore
| | - Zhen Huang
- †NUSNNI-Nanocore, National University of Singapore, Singapore 117411, Singapore
| | - Zhiqi Liu
- †NUSNNI-Nanocore, National University of Singapore, Singapore 117411, Singapore
| | - Shengwei Zeng
- †NUSNNI-Nanocore, National University of Singapore, Singapore 117411, Singapore
| | - Rui Guo
- †NUSNNI-Nanocore, National University of Singapore, Singapore 117411, Singapore
| | - Yongliang Zhao
- †NUSNNI-Nanocore, National University of Singapore, Singapore 117411, Singapore
| | - Kaiyang Zeng
- ∥Department of Mechanical Engineering, National University of Singapore, Singapore 117575, Singapore
| | - Michael Coey
- †NUSNNI-Nanocore, National University of Singapore, Singapore 117411, Singapore
- ¶School of Physics, Trinity College, Dublin 2, Ireland
| | | | - T Venkatesan
- †NUSNNI-Nanocore, National University of Singapore, Singapore 117411, Singapore
- ‡National University of Singapore Graduate School for Integrative Sciences and Engineering (NGS), 28 Medical Drive, Singapore 117456, Singapore
- ⊥Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576, Singapore
- ∇Department of Physics, National University of Singapore, Singapore 117571, Singapore
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