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Das NC, Kim YP, Hong SM, Jang JH. Effects of Top and Bottom Electrodes Materials and Operating Ambiance on the Characteristics of MgF x Based Bipolar RRAMs. Nanomaterials (Basel) 2023; 13:1127. [PMID: 36986021 PMCID: PMC10058438 DOI: 10.3390/nano13061127] [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: 02/21/2023] [Revised: 03/16/2023] [Accepted: 03/20/2023] [Indexed: 06/18/2023]
Abstract
The effects of electrode materials (top and bottom) and the operating ambiances (open-air and vacuum) on the MgFx-based resistive random-access memory (RRAM) devices are studied. Experiment results show that the device's performance and stability depend on the difference between the top and bottom electrodes' work functions. Devices are robust in both environments if the work function difference between the bottom and top electrodes is greater than or equal to 0.70 eV. The operating environment-independent device performance depends on the surface roughness of the bottom electrode materials. Reducing the bottom electrodes' surface roughness will reduce moisture absorption, minimizing the impact of the operating environment. Ti/MgFx/p+-Si memory devices with the minimum surface roughness of the p+-Si bottom electrode show operating environment-independent electroforming-free stable resistive switching properties. The stable memory devices show promising data retentions of >104 s in both environments with DC endurance properties of more than 100 cycles.
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Affiliation(s)
- Nayan C. Das
- Department of Energy Engineering, Korea Institute of Energy Technology, Naju 58330, Republic of Korea
| | - Yong-Pyo Kim
- School of Electrical Engineering and Computer Science, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
| | - Sung-Min Hong
- School of Electrical Engineering and Computer Science, Gwangju Institute of Science and Technology, Gwangju 61005, Republic of Korea
| | - Jae-Hyung Jang
- Department of Energy Engineering, Korea Institute of Energy Technology, Naju 58330, Republic of Korea
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Park J, Choi J, Kim G, Kim G, Kim GS, Song H, Kim YS, Lee Y, Rhee H, Lee HM, Hwang CS, Kim KM. Modified Dynamic Physical Model of Valence Change Mechanism Memristors. ACS Appl Mater Interfaces 2022; 14:35949-35958. [PMID: 35900018 DOI: 10.1021/acsami.2c10944] [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: 06/15/2023]
Abstract
Valence change-type resistance switching behaviors in oxides can be understood by well-established physical models describing the field-driven oxygen vacancy distribution change. In those models, electroformed residual oxygen vacancy filaments are crucial as they work as an electric field concentrator and limit the oxygen vacancy movement along the vertical direction. Therefore, their movement outward by diffusion is negligible. However, this situation may not be applicable in the electroforming-free system, where the field-driven movement is less prominent, and the isotropic oxygen vacancy diffusion by concentration gradient is more significant, which has not been given much consideration in the conventional model. Here, we propose a modified physical model that considers the change in the oxygen vacancies' charged state depending on their concentrations and the resulting change in diffusivity during switching to interpret the electroforming-free device behaviors. The model suggests formation of an hourglass-shaped filament constituting a lower concentration of oxygen vacancies due to the fluid oxygen diffusion in the thin oxide. Consequently, the proposed model can explain the electroforming-free device behaviors, including the retention failure mechanism, and suggest an optimized filament configuration for improved retention characteristics. The proposed model can plausibly explain both the electroformed and the electroforming-free devices. Therefore, it can be a standard model for valence change memristors.
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Affiliation(s)
- Juseong Park
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Jungwoo Choi
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Gwangmin Kim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Geunyoung Kim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Gil Seop Kim
- Department of Materials Science and Engineering, and Inter-University Semiconductor Research Center, Seoul National University, Seoul 08826, Republic of Korea
| | - Hanchan Song
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Yeong Seok Kim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Younghyun Lee
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Hakseung Rhee
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Hyuck Mo Lee
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Cheol Seong Hwang
- Department of Materials Science and Engineering, and Inter-University Semiconductor Research Center, Seoul National University, Seoul 08826, Republic of Korea
| | - Kyung Min Kim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
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Li X, Yang JG, Ma HP, Liu YH, Ji ZG, Huang W, Ou X, Zhang DW, Lu HL. Atomic Layer Deposition of Ga 2O 3/ZnO Composite Films for High-Performance Forming-Free Resistive Switching Memory. ACS Appl Mater Interfaces 2020; 12:30538-30547. [PMID: 32539324 DOI: 10.1021/acsami.0c06476] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The resistive switching behavior in resistive random access memories (RRAMs) using atomic-layer-deposited Ga2O3/ZnO composite film as the dielectric was investigated. By alternatively atomic-layer-depositing Ga2O3 and ZnO with different thickness, we can accurately control the oxygen vacancy concentration. When regulating ZnO to ∼31%, the RRAMs exhibit a forming-free property as well as outstanding performance, including the ratio of a high resistance state to the low resistance state of 1000, retention time of more than 1 × 104 s, and the endurance of 100. By preparing RRAMs of different Zn concentration, we carried out a comparative study and explored the physical origin for the forming-free property as well as good performance. Finally, a unified model is proposed to account for the resistive switching and the current conduction mechanism, providing meaningful insights in the development of high-quality and forming-free RRAMs for future memory and neuromorphic applications.
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Affiliation(s)
- Xing Li
- State Key Laboratory of ASIC and System, Shanghai Institute of Intelligent Electronics & Systems, School of Microelectronics, Fudan University, Shanghai 200433, China
| | - Jian-Guo Yang
- State Key Laboratory of ASIC and System, Shanghai Institute of Intelligent Electronics & Systems, School of Microelectronics, Fudan University, Shanghai 200433, China
| | - Hong-Ping Ma
- State Key Laboratory of ASIC and System, Shanghai Institute of Intelligent Electronics & Systems, School of Microelectronics, Fudan University, Shanghai 200433, China
| | - Yu-Hang Liu
- State Key Laboratory of ASIC and System, Shanghai Institute of Intelligent Electronics & Systems, School of Microelectronics, Fudan University, Shanghai 200433, China
| | - Zhi-Gang Ji
- National Key Laboratory of Science and Technology on Micro/Nano Fabrication, Shanghai Jiaotong University, Shanghai 200240, China
| | - Wei Huang
- State Key Laboratory of ASIC and System, Shanghai Institute of Intelligent Electronics & Systems, School of Microelectronics, Fudan University, Shanghai 200433, China
| | - Xin Ou
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
| | - David Wei Zhang
- State Key Laboratory of ASIC and System, Shanghai Institute of Intelligent Electronics & Systems, School of Microelectronics, Fudan University, Shanghai 200433, China
| | - Hong-Liang Lu
- State Key Laboratory of ASIC and System, Shanghai Institute of Intelligent Electronics & Systems, School of Microelectronics, Fudan University, Shanghai 200433, China
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Cuhadar C, Kim SG, Yang JM, Seo JY, Lee D, Park NG. All-Inorganic Bismuth Halide Perovskite-Like Materials A 3Bi 2I 9 and A 3Bi 1.8Na 0.2I 8.6 (A = Rb and Cs) for Low-Voltage Switching Resistive Memory. ACS Appl Mater Interfaces 2018; 10:29741-29749. [PMID: 29968458 DOI: 10.1021/acsami.8b07103] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [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
As silicon-based metal oxide semiconductor field effect transistors get closer to their scaling limit, the importance of resistive random-access memory devices increases due to their low power consumption, high endurance and retention performance, scalability, and fast switching speed. In the last couple of years, organic-inorganic lead halide perovskites have been used for resistive switching applications, where they outperformed conventional metal oxides in terms of large on/off ratio and low power consumption. However, there were scarce reports on lead-free perovskites for such applications. In this report, we prepared lead-free Au/A3Bi2I9/Pt/Ti/SiO2/Si (A is either Cs+ or Rb+) devices and tested their resistive switching characteristics. They showed a forming step prior to repeating switching, low operating voltage (0.09 V for Rb3Bi2I9 and 0.1 V for Cs3Bi2I9), large on/off ratio (>107), relatively high endurance (200 cycles for Rb3Bi2I9 and 400 cycles for Cs3Bi2I9 cycles), and high retention (1000 s). Such low voltage could be explained by grain boundary-modulated ion drift. Difference in endurance was speculated to be due to the difference in the surface roughness of films because Cs3Bi2I9 films are smoother. To get rid of the forming step, 10% of the Bi3+ cations were substituted with Na+ cations. However, this method only worked on Rb-based structures. This phenomenon was explained by the defect formation energy, which can only be negative in a corner-sharing Rb3Bi2I9 structure compared to a face-sharing octahedral Cs3Bi2I9 structure. As a result, the forming step was removed, and 100 cycles endurance and 1000 s retention performance were obtained. Similarly, the lower endurance is suspected to be due to the poor surface quality of the film.
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Affiliation(s)
- Can Cuhadar
- School of Chemical Engineering , Sungkyunkwan University , Suwon 16419 , Korea
| | - Seul-Gi Kim
- School of Chemical Engineering , Sungkyunkwan University , Suwon 16419 , Korea
| | - June-Mo Yang
- School of Chemical Engineering , Sungkyunkwan University , Suwon 16419 , Korea
| | - Ja-Young Seo
- School of Chemical Engineering , Sungkyunkwan University , Suwon 16419 , Korea
| | - Donghwa Lee
- Department of Materials Science and Engineering , Pohang University of Science and Technology (POSTECH) , Pohang 37673 , Korea
| | - Nam-Gyu Park
- School of Chemical Engineering , Sungkyunkwan University , Suwon 16419 , Korea
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Kim KM, Zhang J, Graves C, Yang JJ, Choi BJ, Hwang CS, Li Z, Williams RS. Low-Power, Self-Rectifying, and Forming-Free Memristor with an Asymmetric Programing Voltage for a High-Density Crossbar Application. Nano Lett 2016; 16:6724-6732. [PMID: 27661260 DOI: 10.1021/acs.nanolett.6b01781] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [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
A Pt/NbOx/TiOy/NbOx/TiN stack integrated on a 30 nm contact via shows a programming current as low as 10 nA and 1 pA for the set and reset switching, respectively, and a self-rectifying ratio as high as ∼105, which are suitable characteristics for low-power memristor applications. It also shows a forming-free characteristic. A charge-trap-associated switching model is proposed to account for this self-rectifying memrisive behavior. In addition, an asymmetric voltage scheme (AVS) to decrease the write power consumption by utilizing this self-rectifying memristor is also described. When the device is used in a 1000 × 1000 crossbar array with the AVS, the programming power can be decreased to 8.0% of the power consumption of a conventional biasing scheme. If the AVS is combined with a nonlinear selector, a power consumption reduction to 0.31% of the reference value is possible.
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Affiliation(s)
- Kyung Min Kim
- Hewlett Packard Labs, Hewlett Packard Enterprise , Palo Alto, California 94304, United States
| | - Jiaming Zhang
- Hewlett Packard Labs, Hewlett Packard Enterprise , Palo Alto, California 94304, United States
| | - Catherine Graves
- Hewlett Packard Labs, Hewlett Packard Enterprise , Palo Alto, California 94304, United States
| | - J Joshua Yang
- Department of Electrical and Computer Engineering, University of Massachusetts , Amherst, Massachusetts 01003, United States
| | - Byung Joon Choi
- Department of Materials Science and Engineering, Seoul National University of Science and Technology , Seoul 139-743, Republic of Korea
| | - Cheol Seong Hwang
- Department of Materials Science and Engineering and Inter-University Semiconductor Research Center, College of Engineering, Seoul National University , Seoul 151-744, Republic of Korea
| | - Zhiyong Li
- Hewlett Packard Labs, Hewlett Packard Enterprise , Palo Alto, California 94304, United States
| | - R Stanley Williams
- Hewlett Packard Labs, Hewlett Packard Enterprise , Palo Alto, California 94304, United States
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Sun Y, Yan X, Zheng X, Liu Y, Zhao Y, Shen Y, Liao Q, Zhang Y. High on-off ratio improvement of ZnO-based forming-free memristor by surface hydrogen annealing. ACS Appl Mater Interfaces 2015; 7:7382-8. [PMID: 25786156 DOI: 10.1021/acsami.5b01080] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [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
In this work, a high-performance, forming-free memristor based on Au/ZnO nanorods/AZO (Al-doped ZnO conductive glass) sandwich structure has been developed by rapid hydrogen annealing treatment. The Ron/Roff rate is dramatically increased from ∼10 to ∼10(4) after the surface treatment. Such an enhanced performance is attributed to the introduced oxygen vacancies layer at the top of ZnO nanorods. The device also exhibits excellent switching and retention stability. In addition, the carrier migration behavior can be well interpreted by classical trap-controlled space charge limited conduction, which verifies the forming of conductive filamentary in low resistive state. On this basis, Arrhenius activation theory is adopted to explain the drifting of oxygen vacancies, which is further confirmed by the time pertinence of resistive switching behavior under different sweep speed. This fabrication approach offers a useful approach to enhance the switching properties for next-generation memory applications.
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Affiliation(s)
- Yihui Sun
- †State Key Laboratory for Advanced Metals and Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Xiaoqin Yan
- †State Key Laboratory for Advanced Metals and Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Xin Zheng
- †State Key Laboratory for Advanced Metals and Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Yichong Liu
- †State Key Laboratory for Advanced Metals and Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Yanguang Zhao
- †State Key Laboratory for Advanced Metals and Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Yanwei Shen
- †State Key Laboratory for Advanced Metals and Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Qingliang Liao
- †State Key Laboratory for Advanced Metals and Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
| | - Yue Zhang
- †State Key Laboratory for Advanced Metals and Materials, School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
- ‡Key Laboratory of New Energy Materials and Technologies, University of Science and Technology Beijing, Beijing 100083, People's Republic of China
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