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Zahoor F, Nisar A, Bature UI, Abbas H, Bashir F, Chattopadhyay A, Kaushik BK, Alzahrani A, Hussin FA. An overview of critical applications of resistive random access memory. NANOSCALE ADVANCES 2024:d4na00158c. [PMID: 39263252 PMCID: PMC11382421 DOI: 10.1039/d4na00158c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 08/10/2024] [Indexed: 09/13/2024]
Abstract
The rapid advancement of new technologies has resulted in a surge of data, while conventional computers are nearing their computational limits. The prevalent von Neumann architecture, where processing and storage units operate independently, faces challenges such as data migration through buses, leading to decreased computing speed and increased energy loss. Ongoing research aims to enhance computing capabilities through the development of innovative chips and the adoption of new system architectures. One noteworthy advancement is Resistive Random Access Memory (RRAM), an emerging memory technology. RRAM can alter its resistance through electrical signals at both ends, retaining its state even after power-down. This technology holds promise in various areas, including logic computing, neural networks, brain-like computing, and integrated technologies combining sensing, storage, and computing. These cutting-edge technologies offer the potential to overcome the performance limitations of traditional architectures, significantly boosting computing power. This discussion explores the physical mechanisms, device structure, performance characteristics, and applications of RRAM devices. Additionally, we delve into the potential future adoption of these technologies at an industrial scale, along with prospects and upcoming research directions.
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Affiliation(s)
- Furqan Zahoor
- Department of Computer Engineering, College of Computer Sciences and Information Technology, King Faisal University Saudi Arabia
| | - Arshid Nisar
- Department of Electronics and Communication Engineering, Indian Institute of Technology Roorkee India
| | - Usman Isyaku Bature
- Department of Electrical and Electronics Engineering, Universiti Teknologi Petronas Malaysia
| | - Haider Abbas
- Department of Nanotechnology and Advanced Materials Engineering, Sejong University Seoul 143-747 Republic of Korea
| | - Faisal Bashir
- Department of Computer Engineering, College of Computer Sciences and Information Technology, King Faisal University Saudi Arabia
| | - Anupam Chattopadhyay
- College of Computing and Data Science, Nanyang Technological University 639798 Singapore
| | - Brajesh Kumar Kaushik
- Department of Electronics and Communication Engineering, Indian Institute of Technology Roorkee India
| | - Ali Alzahrani
- Department of Computer Engineering, College of Computer Sciences and Information Technology, King Faisal University Saudi Arabia
| | - Fawnizu Azmadi Hussin
- Department of Electrical and Electronics Engineering, Universiti Teknologi Petronas Malaysia
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Yuan Y, He L, Qian J, Song S, Song Z, Liu R, Zhai J. Improvement of Multilevel Memory Performance of MnTe Thin Films by Ta Doping. ACS APPLIED MATERIALS & INTERFACES 2024; 16:17778-17786. [PMID: 38534114 DOI: 10.1021/acsami.3c19048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
The pressing need for data storage in the era of big data has driven the development of new storage technologies. As a prominent contender for next-generation memory, phase-change memory can effectively increase storage density through multilevel cell operation and can be applied to neuromorphic and in-memory computing. Herein, the structure and properties of Ta-doped MnTe thin films and their inherent correlations are systematically investigated. Amorphous MnTe thin films sequentially precipitated cubic MnTe2 and hexagonal Te phases with increasing temperature, causing resistance changes. Ta doping inhibited phase segregation in the films and improved their thermal stability in the amorphous state. A phase-change memory cell based on a Ta2.8%-MnTe thin film exhibited three stable resistive states with low resistive drift coefficients. The study findings reveal the possibility of regulating the two-step phase-change process in Ta-MnTe thin films, providing insight into the design of multilevel phase-change memory.
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Affiliation(s)
- Yukang Yuan
- Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education, Functional Materials Research Laboratory, School of Materials Science and Engineering, Tongji University, Shanghai 201804, People's Republic of China
| | - Lai He
- Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education, Functional Materials Research Laboratory, School of Materials Science and Engineering, Tongji University, Shanghai 201804, People's Republic of China
| | - Jin Qian
- Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education, Functional Materials Research Laboratory, School of Materials Science and Engineering, Tongji University, Shanghai 201804, People's Republic of China
| | - Sannian Song
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, People's Republic of China
| | - Zhitang Song
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, People's Republic of China
| | - Ruirui Liu
- School of Materials Science and Engineering, Shanghai Institute of Technology, Shanghai 201418, People's Republic of China
| | - Jiwei Zhai
- Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education, Functional Materials Research Laboratory, School of Materials Science and Engineering, Tongji University, Shanghai 201804, People's Republic of China
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Song WX, Tang Q, Zhao J, Veron M, Zhou X, Zheng Y, Cai D, Cheng Y, Xin T, Liu ZP, Song Z. Tuning the Crystallization Mechanism by Composition Vacancy in Phase Change Materials. ACS APPLIED MATERIALS & INTERFACES 2024. [PMID: 38498850 DOI: 10.1021/acsami.3c18538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/20/2024]
Abstract
Interface-influenced crystallization is crucial to understanding the nucleation- and growth-dominated crystallization mechanisms in phase-change materials (PCMs), but little is known. Here, we find that composition vacancy can reduce the interface energy by decreasing the coordinate number (CN) at the interface. Compared to growth-dominated GeTe, nucleation-dominated Ge2Sb2Te5 (GST) exhibits composition vacancies in the (111) interface to saturate or stabilize the Te-terminated plane. Together, the experimental and computational results provide evidence that GST prefers (111) with reduced CN. Furthermore, the (8 - n) bonding rule, rather than CN6, in the nuclei of both GeTe and GST results in lower interface energy, allowing crystallization to be observed at the simulation time in general PCMs. In comparison to GeTe, the reduced CN in the GST nuclei further decreases the interface energy, promoting faster nucleation. Our findings provide an approach to designing ultrafast phase-change memory through vacancy-stabilized interfaces.
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Affiliation(s)
- Wen-Xiong Song
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
| | - Qiongyan Tang
- Key Laboratory of Polar Materials and Devices (MOE), Department of Electronics, East China Normal University, Shanghai 200241, China
| | - Jin Zhao
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
| | - Muriel Veron
- University Grenoble Alpes, CNRS, SIMAP, 38000 Grenoble, France
| | - Xilin Zhou
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
| | - Yonghui Zheng
- Key Laboratory of Polar Materials and Devices (MOE), Department of Electronics, East China Normal University, Shanghai 200241, China
| | - Daolin Cai
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
| | - Yan Cheng
- Key Laboratory of Polar Materials and Devices (MOE), Department of Electronics, East China Normal University, Shanghai 200241, China
| | - Tianjiao Xin
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
| | - Zhi-Pan Liu
- Department of Chemistry, Fudan University, Shanghai 200433, China
| | - Zhitang Song
- National Key Laboratory of Materials for Integrated Circuits, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
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Liu C, Tang Q, Zheng Y, Zhao J, Song W, Cheng Y. Effect of vacancy ordering on the grain growth of Ge 2Sb 2Te 5film. NANOTECHNOLOGY 2023; 34:155703. [PMID: 36652702 DOI: 10.1088/1361-6528/acb446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 01/18/2023] [Indexed: 06/17/2023]
Abstract
Ge2Sb2Te5(GST) is the most widely used matrix material in phase change random access memory (PCRAM). In practical PCRAM device, the formed large hexagonal phase in GST material is not preferred, especially when the size of storage architecture is continually scaling down. In this report, with the aid of spherical-aberration corrected transmission electron microscopy (Cs-TEM), the grain growth behavior during thein situheating process in GST alloy is investigated. Generally, the metastable face-centered-cubic (f-) grain tends to grow up with increasing temperature. However, a part of f-phase nanograins with {111} surface plane does not grow very obviously. Thus, the grain size distribution at high temperature shows a large average grain size as well as a large standard deviation. When the vacancy ordering layers forms at the grain boundary area in the nanograins, which is parallel to {111} surface plane, it could stabilize and refine these f-phase grains. By elaborating the relationship between the grain growth and the vacancy ordering process in GST, this work offers a new perspective for the grain refinement in GST-based PCRAM devices.
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Affiliation(s)
- Cheng Liu
- Key Laboratory of Polar Materials and Devices (MOE), Department of Electronics, East China Normal University, Shanghai 200241, People's Republic of China
| | - Qiongyan Tang
- Key Laboratory of Polar Materials and Devices (MOE), Department of Electronics, East China Normal University, Shanghai 200241, People's Republic of China
| | - Yonghui Zheng
- Key Laboratory of Polar Materials and Devices (MOE), Department of Electronics, East China Normal University, Shanghai 200241, People's Republic of China
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, People's Republic of China
- Chongqing Key Laboratory of Precision Optics, Chongqing Institute of East China Normal University, Chongqing 401120, People's Republic of China
| | - Jin Zhao
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, People's Republic of China
| | - Wenxiong Song
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, People's Republic of China
| | - Yan Cheng
- Key Laboratory of Polar Materials and Devices (MOE), Department of Electronics, East China Normal University, Shanghai 200241, People's Republic of China
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5
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Wet spinning of strong cellulosic fibres with incorporation of phase change material capsules stabilized by cellulose nanocrystals. Carbohydr Polym 2023; 312:120734. [PMID: 37059568 DOI: 10.1016/j.carbpol.2023.120734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 02/16/2023] [Accepted: 02/19/2023] [Indexed: 02/25/2023]
Abstract
Incorporating a phase change material (PCM) into fibres allows the fabrication of smart textiles with thermo-regulating properties. Previously, such fibres have been made from thermoplastic polymers, usually petroleum-based and non-biodegradable, or from regenerated cellulose, such as viscose. Herein, strong fibres are developed from aqueous dispersions of nano-cellulose and dispersed microspheres with phase changing characteristics using a wet spinning technique employing a pH shift approach. Good distribution of the microspheres and proper compatibility with the cellulosic matrix was demonstrated by formulating the wax as a Pickering emulsion using cellulose nanocrystals (CNC) as stabilizing particles. The wax was subsequently incorporated into a dispersion of cellulose nanofibrils, the latter being responsible for the mechanical strength of the spun fibres. It was possible to produce fibres highly loaded with the microspheres (40 wt%) with a tenacity of 13 cN tex-1 (135 MPa). The fibres possessed good thermo-regulating features by absorbing and releasing heat without undergoing structural changes, while maintaining the PCM domain sizes intact. Finally, good washing fastness and PCM leak resistance were demonstrated, making the fibres suitable for thermo-regulative applications. Continuous fabrication of bio-based fibres with entrapped PCMs may find applications as reinforcements in composites or hybrid filaments.
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Zheng C, Simpson RE, Tang K, Ke Y, Nemati A, Zhang Q, Hu G, Lee C, Teng J, Yang JKW, Wu J, Qiu CW. Enabling Active Nanotechnologies by Phase Transition: From Electronics, Photonics to Thermotics. Chem Rev 2022; 122:15450-15500. [PMID: 35894820 DOI: 10.1021/acs.chemrev.2c00171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Phase transitions can occur in certain materials such as transition metal oxides (TMOs) and chalcogenides when there is a change in external conditions such as temperature and pressure. Along with phase transitions in these phase change materials (PCMs) come dramatic contrasts in various physical properties, which can be engineered to manipulate electrons, photons, polaritons, and phonons at the nanoscale, offering new opportunities for reconfigurable, active nanodevices. In this review, we particularly discuss phase-transition-enabled active nanotechnologies in nonvolatile electrical memory, tunable metamaterials, and metasurfaces for manipulation of both free-space photons and in-plane polaritons, and multifunctional emissivity control in the infrared (IR) spectrum. The fundamentals of PCMs are first introduced to explain the origins and principles of phase transitions. Thereafter, we discuss multiphysical nanodevices for electronic, photonic, and thermal management, attesting to the broad applications and exciting promises of PCMs. Emerging trends and valuable applications in all-optical neuromorphic devices, thermal data storage, and encryption are outlined in the end.
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Affiliation(s)
- Chunqi Zheng
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583, Singapore.,NUS Graduate School, National University of Singapore, Singapore 119077, Singapore
| | - Robert E Simpson
- Engineering Product Development, Singapore University of Technology and Design (SUTD), Singapore 487372, Singapore
| | - Kechao Tang
- Key Laboratory of Microelectronic Devices and Circuits (MOE), School of Integrated Circuits, Peking University, Beijing 100871, China
| | - Yujie Ke
- Engineering Product Development, Singapore University of Technology and Design (SUTD), Singapore 487372, Singapore
| | - Arash Nemati
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), Singapore 138634, Singapore
| | - Qing Zhang
- School of Physics, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Guangwei Hu
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583, Singapore
| | - Chengkuo Lee
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583, Singapore
| | - Jinghua Teng
- Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), Singapore 138634, Singapore
| | - Joel K W Yang
- Engineering Product Development, Singapore University of Technology and Design (SUTD), Singapore 487372, Singapore.,Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), Singapore 138634, Singapore
| | - Junqiao Wu
- Department of Materials Science and Engineering, University of California, Berkeley, and Lawrence Berkeley National Laboratory, California 94720, United States
| | - Cheng-Wei Qiu
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583, Singapore
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7
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Portavoce A, Roland G, Remondina J, Descoins M, Bertoglio M, Amalraj M, Eyméoud P, Dutartre D, Lorut F, Putero M. Kinetic Monte Carlo simulations of Ge-Sb-Te thin film crystallization. NANOTECHNOLOGY 2022; 33:295601. [PMID: 35439738 DOI: 10.1088/1361-6528/ac6813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 04/19/2022] [Indexed: 06/14/2023]
Abstract
Simulation of atomic redistribution in Ge-Sb-Te (GST)-based memory cells during SET/RESET cycling is needed in order to understand GST memory cell failure and to design improved non-volatile memories. However, this type of atomic scale simulations is extremely challenging. In this work, we propose to use a simplified GST system in order to catch the basics of atomic redistribution in Ge-rich GST (GrGST) films using atomistic kinetic Monte Carlo simulations. Comparison between experiments and simulations shows good agreements regarding the influence of Ge excess on GrGST crystallization, as well as concerning the GST growth kinetic in GrGST films, suggesting the crystallized GST ternary compound to be off-stoichiometric. According to the simulation of atomic redistribution in GrGST films during SET/RESET cycling, the film microstructure stabilized during cycling is significantly dependent of the GST ternary phase stoichiometry. The use of amorphous layers exhibiting the GST ternary phase stoichiometry placed at the bottom or at the top of the GrGST layer is shown to be a way of controlling the microstructure evolution of the film during cycling. The significant evolution of the local composition in the amorphous solution during cycling suggests a non-negligible variation of the crystallization temperature with operation time.
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Affiliation(s)
- A Portavoce
- Aix-Marseille University/CNRS, IM2NP, Faculté des Sciences de Saint-Jérôme case 142, F-13397 Marseille, France
| | - G Roland
- Aix-Marseille University/CNRS, IM2NP, Faculté des Sciences de Saint-Jérôme case 142, F-13397 Marseille, France
- STMicroelectronics, 850 Rue Jean Monnet, F-38920 Crolles, France
| | - J Remondina
- Aix-Marseille University/CNRS, IM2NP, Faculté des Sciences de Saint-Jérôme case 142, F-13397 Marseille, France
| | - M Descoins
- Aix-Marseille University/CNRS, IM2NP, Faculté des Sciences de Saint-Jérôme case 142, F-13397 Marseille, France
| | - M Bertoglio
- Aix-Marseille University/CNRS, IM2NP, Faculté des Sciences de Saint-Jérôme case 142, F-13397 Marseille, France
| | - M Amalraj
- Aix-Marseille University/CNRS, IM2NP, Faculté des Sciences de Saint-Jérôme case 142, F-13397 Marseille, France
| | - P Eyméoud
- Aix-Marseille University/CNRS, IM2NP, Faculté des Sciences de Saint-Jérôme case 142, F-13397 Marseille, France
| | - D Dutartre
- STMicroelectronics, 850 Rue Jean Monnet, F-38920 Crolles, France
| | - F Lorut
- STMicroelectronics, 850 Rue Jean Monnet, F-38920 Crolles, France
| | - M Putero
- Aix-Marseille University/CNRS, IM2NP, Faculté des Sciences de Saint-Jérôme case 142, F-13397 Marseille, France
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8
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Xu Y, Zhou Y, Wang XD, Zhang W, Ma E, Deringer VL, Mazzarello R. Unraveling Crystallization Mechanisms and Electronic Structure of Phase-Change Materials by Large-Scale Ab Initio Simulations. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2109139. [PMID: 34994023 DOI: 10.1002/adma.202109139] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 12/17/2021] [Indexed: 06/14/2023]
Abstract
Ge-Sb-Te ("GST") alloys are leading phase-change materials for digital memories and neuro-inspired computing. Upon fast crystallization, these materials form rocksalt-like phases with large structural and vacancy disorder, leading to an insulating phase at low temperature. Here, a comprehensive description of crystallization, structural disorder, and electronic properties of GeSb2 Te4 based on realistic, quantum-mechanically based ("ab initio") computer simulations with system sizes of more than 1000 atoms is provided. It is shown how an analysis of the crystallization mechanism based on the smooth overlap of atomic positions kernel reveals the evolution of both geometrical and chemical order. The connection between structural and electronic properties of the disordered, as-crystallized models, which are relevant to the transport properties of GST, is then studied. Furthermore, it is shown how antisite defects and extended Sb-rich motifs can lead to Anderson localization in the conduction band. Beyond memory applications, these findings are therefore more generally relevant to disordered rocksalt-like chalcogenides that exhibit self-doping, since they can explain the origin of Anderson insulating behavior in both p- and n-doped chalcogenide materials.
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Affiliation(s)
- Yazhi Xu
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China
- Institute for Theoretical Solid State Physics, RWTH Aachen University, Aachen, 52056, Germany
| | - Yuxing Zhou
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China
- Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, Oxford, OX1 3QR, UK
| | - Xu-Dong Wang
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China
- Center for Alloy Innovation and Design (CAID), School of Materials Science and Engineering, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Wei Zhang
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China
- Center for Alloy Innovation and Design (CAID), School of Materials Science and Engineering, Xi'an Jiaotong University, Xi'an, 710049, China
- Pazhou Lab, Pengcheng National Laboratory in Guangzhou, Guangzhou, 510320, China
| | - En Ma
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, China
- Center for Alloy Innovation and Design (CAID), School of Materials Science and Engineering, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Volker L Deringer
- Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, Oxford, OX1 3QR, UK
| | - Riccardo Mazzarello
- Institute for Theoretical Solid State Physics, RWTH Aachen University, Aachen, 52056, Germany
- JARA-FIT and JARA-HPC, RWTH Aachen University, Aachen, 52056, Germany
- Department of Physics, Sapienza University of Rome, Rome, 00185, Italy
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Abd-Elnaiem AM, Abdelraheem AM, Abdel-Rahim MA, Moustafa S. Substituting Silver for Tellurium in Selenium–Tellurium Thin Films for Improving the Optical Characteristics. J Inorg Organomet Polym Mater 2022. [DOI: 10.1007/s10904-022-02250-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
AbstractThe effect of Ag content on the linear and nonlinear optical characteristics of thermal evaporated Se90−xTe10Agx thin films, 100 nm thick, (where x = 0, 2, 4, 6, and 8 at.%) has been examined. The optical measurements were reviewed in the wavelength range of 390–2500 nm based on the transmittance and reflectance data, and the amorphous state of the as-prepared thin film was confirmed by X-ray diffraction. The absorption coefficient, extinction coefficient, bandgap, optical density, optical conductivity, dissipation factor, and other optical properties were examined and discussed. For all of the samples, the extinction coefficient of Se90−xTe10Agx declines as the wavelength and Ag concentration rise, whereas the absorption coefficient increases linearly with incident photon energy. Furthermore, the optical bandgap and the width of localized states alter in the exact opposite direction, which is consistent with previously reported findings. The decrease in the optical band gap as Ag concentration increases could be attributable to an increase in the amount of disorder in the materials and the density of defect states. Other critical optoelectronic characteristics are also determined, and they are found to be influenced by the Ag ratio and photon wavelength. These materials may be ideal for optical memory applications due to their high absorption coefficient and compositional dependence of absorption.
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Wang X, Qi H, Hu X, Yu Z, Ding S, Du Z, Gong Q. Advances in Photonic Devices Based on Optical Phase-Change Materials. Molecules 2021; 26:2813. [PMID: 34068710 PMCID: PMC8126227 DOI: 10.3390/molecules26092813] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 04/23/2021] [Accepted: 05/07/2021] [Indexed: 11/16/2022] Open
Abstract
Phase-change materials (PCMs) are important photonic materials that have the advantages of a rapid and reversible phase change, a great difference in the optical properties between the crystalline and amorphous states, scalability, and nonvolatility. With the constant development in the PCM platform and integration of multiple material platforms, more and more reconfigurable photonic devices and their dynamic regulation have been theoretically proposed and experimentally demonstrated, showing the great potential of PCMs in integrated photonic chips. Here, we review the recent developments in PCMs and discuss their potential for photonic devices. A universal overview of the mechanism of the phase transition and models of PCMs is presented. PCMs have injected new life into on-chip photonic integrated circuits, which generally contain an optical switch, an optical logical gate, and an optical modulator. Photonic neural networks based on PCMs are another interesting application of PCMs. Finally, the future development prospects and problems that need to be solved are discussed. PCMs are likely to have wide applications in future intelligent photonic systems.
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Affiliation(s)
- Xiaoxiao Wang
- Collaborative Innovation Center of Quantum Matter & Frontiers Science Center for Nano-Optoelectronics, State Key Laboratory for Mesoscopic Physics & Department of Physics, Beijing Academy of Quantum Information Sciences, Peking University, Beijing 100871, China; (X.W.); (H.Q.); (Z.Y.); (S.D.); (Z.D.); (Q.G.)
| | - Huixin Qi
- Collaborative Innovation Center of Quantum Matter & Frontiers Science Center for Nano-Optoelectronics, State Key Laboratory for Mesoscopic Physics & Department of Physics, Beijing Academy of Quantum Information Sciences, Peking University, Beijing 100871, China; (X.W.); (H.Q.); (Z.Y.); (S.D.); (Z.D.); (Q.G.)
| | - Xiaoyong Hu
- Collaborative Innovation Center of Quantum Matter & Frontiers Science Center for Nano-Optoelectronics, State Key Laboratory for Mesoscopic Physics & Department of Physics, Beijing Academy of Quantum Information Sciences, Peking University, Beijing 100871, China; (X.W.); (H.Q.); (Z.Y.); (S.D.); (Z.D.); (Q.G.)
- Peking University Yangtze Delta Institute of Optoelectronics, Nantong 226010, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China
| | - Zixuan Yu
- Collaborative Innovation Center of Quantum Matter & Frontiers Science Center for Nano-Optoelectronics, State Key Laboratory for Mesoscopic Physics & Department of Physics, Beijing Academy of Quantum Information Sciences, Peking University, Beijing 100871, China; (X.W.); (H.Q.); (Z.Y.); (S.D.); (Z.D.); (Q.G.)
| | - Shaoqi Ding
- Collaborative Innovation Center of Quantum Matter & Frontiers Science Center for Nano-Optoelectronics, State Key Laboratory for Mesoscopic Physics & Department of Physics, Beijing Academy of Quantum Information Sciences, Peking University, Beijing 100871, China; (X.W.); (H.Q.); (Z.Y.); (S.D.); (Z.D.); (Q.G.)
| | - Zhuochen Du
- Collaborative Innovation Center of Quantum Matter & Frontiers Science Center for Nano-Optoelectronics, State Key Laboratory for Mesoscopic Physics & Department of Physics, Beijing Academy of Quantum Information Sciences, Peking University, Beijing 100871, China; (X.W.); (H.Q.); (Z.Y.); (S.D.); (Z.D.); (Q.G.)
| | - Qihuang Gong
- Collaborative Innovation Center of Quantum Matter & Frontiers Science Center for Nano-Optoelectronics, State Key Laboratory for Mesoscopic Physics & Department of Physics, Beijing Academy of Quantum Information Sciences, Peking University, Beijing 100871, China; (X.W.); (H.Q.); (Z.Y.); (S.D.); (Z.D.); (Q.G.)
- Peking University Yangtze Delta Institute of Optoelectronics, Nantong 226010, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China
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11
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Xu Y, Wang X, Zhang W, Schäfer L, Reindl J, vom Bruch F, Zhou Y, Evang V, Wang J, Deringer VL, Ma E, Wuttig M, Mazzarello R. Materials Screening for Disorder-Controlled Chalcogenide Crystals for Phase-Change Memory Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2006221. [PMID: 33491816 PMCID: PMC11468882 DOI: 10.1002/adma.202006221] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 12/14/2020] [Indexed: 06/12/2023]
Abstract
Tailoring the degree of disorder in chalcogenide phase-change materials (PCMs) plays an essential role in nonvolatile memory devices and neuro-inspired computing. Upon rapid crystallization from the amorphous phase, the flagship Ge-Sb-Te PCMs form metastable rocksalt-like structures with an unconventionally high concentration of vacancies, which results in disordered crystals exhibiting Anderson-insulating transport behavior. Here, ab initio simulations and transport experiments are combined to extend these concepts to the parent compound of Ge-Sb-Te alloys, viz., binary Sb2 Te3 , in the metastable rocksalt-type modification. Then a systematic computational screening over a wide range of homologous, binary and ternary chalcogenides, elucidating the critical factors that affect the stability of the rocksalt structure is carried out. The findings vastly expand the family of disorder-controlled main-group chalcogenides toward many more compositions with a tunable bandgap size for demanding phase-change applications, as well as a varying strength of spin-orbit interaction for the exploration of potential topological Anderson insulators.
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Affiliation(s)
- Yazhi Xu
- Center for Advancing Materials Performance from the NanoscaleState Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
- Institute for Theoretical Solid‐State PhysicsJARA‐FIT and JARA‐HPCRWTH Aachen University52056AachenGermany
| | - Xudong Wang
- Center for Advancing Materials Performance from the NanoscaleState Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
- Center for Alloy Innovation and Design (CAID)Materials Studio for Neuro‐Inspired ComputingXi'an Jiaotong UniversityXi'an710049China
| | - Wei Zhang
- Center for Advancing Materials Performance from the NanoscaleState Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
- Center for Alloy Innovation and Design (CAID)Materials Studio for Neuro‐Inspired ComputingXi'an Jiaotong UniversityXi'an710049China
| | - Lisa Schäfer
- I. Institute of Physics (IA)JARA‐FIT and JARA‐HPCRWTH Aachen University52056AachenGermany
| | - Johannes Reindl
- I. Institute of Physics (IA)JARA‐FIT and JARA‐HPCRWTH Aachen University52056AachenGermany
| | - Felix vom Bruch
- I. Institute of Physics (IA)JARA‐FIT and JARA‐HPCRWTH Aachen University52056AachenGermany
| | - Yuxing Zhou
- Center for Advancing Materials Performance from the NanoscaleState Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
- Center for Alloy Innovation and Design (CAID)Materials Studio for Neuro‐Inspired ComputingXi'an Jiaotong UniversityXi'an710049China
| | - Valentin Evang
- Institute for Theoretical Solid‐State PhysicsJARA‐FIT and JARA‐HPCRWTH Aachen University52056AachenGermany
| | - Jiang‐Jing Wang
- Center for Advancing Materials Performance from the NanoscaleState Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
- I. Institute of Physics (IA)JARA‐FIT and JARA‐HPCRWTH Aachen University52056AachenGermany
| | - Volker L. Deringer
- Department of ChemistryInorganic Chemistry LaboratoryUniversity of OxfordOxfordOX1 3QRUK
| | - En Ma
- Center for Advancing Materials Performance from the NanoscaleState Key Laboratory for Mechanical Behavior of MaterialsXi'an Jiaotong UniversityXi'an710049China
- Center for Alloy Innovation and Design (CAID)Materials Studio for Neuro‐Inspired ComputingXi'an Jiaotong UniversityXi'an710049China
| | - Matthias Wuttig
- I. Institute of Physics (IA)JARA‐FIT and JARA‐HPCRWTH Aachen University52056AachenGermany
- Peter Grünberg Institute (PGI 10)Forschungszentrum Jülich GmbH52425JülichGermany
| | - Riccardo Mazzarello
- Institute for Theoretical Solid‐State PhysicsJARA‐FIT and JARA‐HPCRWTH Aachen University52056AachenGermany
- Present address:
Department of PhysicsSapienza University of Rome00185RomeItaly
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12
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Abstract
The article deals with dendritic structures resulting from self-organization processes in aqueous solutions of albumin proteins. The methods for obtaining the structures and experimental results are presented. It is shown that dendrites are fractal structures that are symmetric under certain conditions of their formation and can have different characteristics depending on the isothermal dehydration of liquid samples. The fractal dimension of the structures in films of the albumin protein solution has been calculated. Dependences of the fractal dimension on the concentrations of salts and protein in the initial solutions and also on the dehydration temperature have been revealed. It has been shown that as the protein concentration in the solution grows, the salt concentration for the initiation of the dendritic structure formation increases. It has been found that the temperature dependences of the fractal dimension of the structures become smoother with increasing protein concentration in solutions. The relationship between geometric characteristics of dendrites and self-organization parameters during drying is discussed.
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13
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Jia S, Li H, Gotoh T, Longeaud C, Zhang B, Lyu J, Lv S, Zhu M, Song Z, Liu Q, Robertson J, Liu M. Ultrahigh drive current and large selectivity in GeS selector. Nat Commun 2020; 11:4636. [PMID: 32934210 PMCID: PMC7493911 DOI: 10.1038/s41467-020-18382-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 08/18/2020] [Indexed: 11/09/2022] Open
Abstract
Selector devices are indispensable components of large-scale nonvolatile memory and neuromorphic array systems. Besides the conventional silicon transistor, two-terminal ovonic threshold switching device with much higher scalability is currently the most industrially favored selector technology. However, current ovonic threshold switching devices rely heavily on intricate control of material stoichiometry and generally suffer from toxic and complex dopants. Here, we report on a selector with a large drive current density of 34 MA cm-2 and a ~106 high nonlinearity, realized in an environment-friendly and earth-abundant sulfide binary semiconductor, GeS. Both experiments and first-principles calculations reveal Ge pyramid-dominated network and high density of near-valence band trap states in amorphous GeS. The high-drive current capacity is associated with the strong Ge-S covalency and the high nonlinearity could arise from the synergy of the mid-gap traps assisted electronic transition and local Ge-Ge chain growth as well as locally enhanced bond alignment under high electric field.
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Affiliation(s)
- Shujing Jia
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Micro-System and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, China
- Key Laboratory of Microelectronic Devices and Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing, 100029, China
- University of Chinese Academy of Sciences, Beijing, 100029, China
| | - Huanglong Li
- Department of Precision Instrument, Tsinghua University, Beijing, 100084, China
- Chinese Institute for Brain Research, Beijing, 102206, China
| | - Tamihiro Gotoh
- Department of Physics, Graduate School of Science and Technology, Gunma University, Maebashi, 3718510, Japan
| | - Christophe Longeaud
- Group of Electrical Engineering of Paris, CNRS, Centrale Supelec, Paris Saclay and Sorbonne Universities, Plateau de Moulon, 91190, Gif sur Yvette, France
| | - Bin Zhang
- Analytical and Testing Center of Chongqing University, Chongqing, 401331, China
| | - Juan Lyu
- Department of Precision Instrument, Tsinghua University, Beijing, 100084, China
| | - Shilong Lv
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Micro-System and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, China
| | - Min Zhu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Micro-System and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, China.
| | - Zhitang Song
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Micro-System and Information Technology, Chinese Academy of Sciences, Shanghai, 200050, China.
| | - Qi Liu
- Key Laboratory of Microelectronic Devices and Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing, 100029, China.
| | - John Robertson
- Engineering Department, University of Cambridge, Cambridge, CB3 0FA, UK
| | - Ming Liu
- Key Laboratory of Microelectronic Devices and Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing, 100029, China
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14
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Feng J, Lotnyk A, Bryja H, Wang X, Xu M, Lin Q, Cheng X, Xu M, Tong H, Miao X. "Stickier"-Surface Sb 2Te 3 Templates Enable Fast Memory Switching of Phase Change Material GeSb 2Te 4 with Growth-Dominated Crystallization. ACS APPLIED MATERIALS & INTERFACES 2020; 12:33397-33407. [PMID: 32597166 DOI: 10.1021/acsami.0c07973] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Ge-Sb-Te (GST)-based phase-change memory (PCM) excels in the switching performance but remains insufficient of the operating speed to replace cache memory (the fastest memory in a computer). In this work, a novel approach using Sb2Te3 templates is proposed to boost the crystallization speed of GST by five times faster. This is because such a GST/Sb2Te3 heterostructure changes the crystallizing mode of GST from the nucleation-dominated to the faster growth-dominated one, as confirmed by high-resolution transmission electron microscopy, which captures the interface-induced epitaxial growth of GST on Sb2Te3 templates in devices. Ab initio molecular dynamic simulations reveal that Sb2Te3 templates can render GST sublayers faster crystallization speed because Sb2Te3's "sticky" surface contains lots of unpaired electrons that may attract Ge atoms with less antibonding interactions. Our work not only proposes a template-assisted PCM with fast speed but also uncovers the hidden mechanism of Sb2Te3's sticky surface, which can be used for future material selection.
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Affiliation(s)
- Jinlong Feng
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
- Leibniz Institute of Surface Engineering (IOM), Permoserstr. 15, Leipzig 04318, Germany
- Hubei Key Laboratory of Advanced Memories, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Andriy Lotnyk
- Leibniz Institute of Surface Engineering (IOM), Permoserstr. 15, Leipzig 04318, Germany
- Laboratory of Infrared Materials and Devices, The Research Institute of Advanced Technologies, Ningbo University, Ningbo 315211, China
| | - Hagen Bryja
- Leibniz Institute of Surface Engineering (IOM), Permoserstr. 15, Leipzig 04318, Germany
| | - Xiaojie Wang
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
- Hubei Key Laboratory of Advanced Memories, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Meng Xu
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
- Hubei Key Laboratory of Advanced Memories, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Qi Lin
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
- Hubei Key Laboratory of Advanced Memories, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xiaomin Cheng
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
- Hubei Key Laboratory of Advanced Memories, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Ming Xu
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
- Hubei Key Laboratory of Advanced Memories, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Hao Tong
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
- Hubei Key Laboratory of Advanced Memories, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xiangshui Miao
- Wuhan National Laboratory for Optoelectronics, School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
- Hubei Key Laboratory of Advanced Memories, Huazhong University of Science and Technology, Wuhan 430074, China
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15
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Lee TH, Elliott SR. Chemical Bonding in Chalcogenides: The Concept of Multicenter Hyperbonding. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2000340. [PMID: 32458525 DOI: 10.1002/adma.202000340] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 04/18/2020] [Accepted: 04/28/2020] [Indexed: 06/11/2023]
Abstract
The precise nature of chemical-bonding interactions in amorphous, and crystalline, chalcogenides is still unclear due to the complexity arising from the delocalization of bonding, and nonbonding, electrons. Although an increasing degree of electron delocalization for elements down a column of the periodic table is widely recognized, its influence on chemical-bonding interactions, and on consequent material properties, of chalcogenides has not previously been comprehensively understood from an atomistic point of view. Here, a chemical-bonding framework is provided for understanding the behavior of chalcogenides (and, in principle, other lone-pair materials) by studying prototypical telluride nonvolatile-memory, "phase-change" materials (PCMs), and related chalcogenide compounds, via density-functional-theory molecular-dynamics (DFT-MD) simulations. Identification of the presence of previously unconsidered multicenter "hyperbonding" (lone-pair-antibonding-orbital) interactions elucidates not only the origin of various material properties, and their contrast in magnitude between amorphous and crystalline phases, but also the very similar chemical-bonding nature between crystalline PCMs and one of the bonding subgroups (with the same bond length) found in amorphous PCMs, in marked contrast to existing viewpoints. The structure-property relationship established from this new bonding-interaction perspective will help in designing improved chalcogenide materials for diverse applications, based on a fundamental chemical-bonding point of view.
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Affiliation(s)
- Tae Hoon Lee
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Stephen R Elliott
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
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16
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Tholapi R, Gallard M, Burle N, Guichet C, Escoubas S, Putero M, Mocuta C, Richard MI, Chahine R, Sabbione C, Bernard M, Fellouh L, Noé P, Thomas O. Stress Buildup Upon Crystallization of GeTe Thin Films: Curvature Measurements and Modelling. NANOMATERIALS (BASEL, SWITZERLAND) 2020; 10:E1247. [PMID: 32604948 PMCID: PMC7353090 DOI: 10.3390/nano10061247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 06/16/2020] [Accepted: 06/22/2020] [Indexed: 06/11/2023]
Abstract
Phase change materials are attractive materials for non-volatile memories because of their ability to switch reversibly between an amorphous and a crystal phase. The volume change upon crystallization induces mechanical stress that needs to be understood and controlled. In this work, we monitor stress evolution during crystallization in thin GeTe films capped with SiOx, using optical curvature measurements. A 150 MPa tensile stress buildup is measured when the 100 nm thick film crystallizes. Stress evolution is a result of viscosity increase with time and a tentative model is proposed that renders qualitatively the observed features.
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Affiliation(s)
- Rajkiran Tholapi
- Aix Marseille Univ, U. Toulon, CNRS, IM2NP (Institut Matériaux Microélectronique et Nanosciences de Provence), Campus St-Jérôme, 13397 Marseille CEDEX 20, France; (M.G.); (N.B.); (C.G.); (S.E.); (M.P.); (M.-I.R.)
| | - Manon Gallard
- Aix Marseille Univ, U. Toulon, CNRS, IM2NP (Institut Matériaux Microélectronique et Nanosciences de Provence), Campus St-Jérôme, 13397 Marseille CEDEX 20, France; (M.G.); (N.B.); (C.G.); (S.E.); (M.P.); (M.-I.R.)
- Synchrotron SOLEIL, l’Orme des Merisiers, Saint-Aubin–BP 48, 91192 Gif-sur-Yvette, France;
| | - Nelly Burle
- Aix Marseille Univ, U. Toulon, CNRS, IM2NP (Institut Matériaux Microélectronique et Nanosciences de Provence), Campus St-Jérôme, 13397 Marseille CEDEX 20, France; (M.G.); (N.B.); (C.G.); (S.E.); (M.P.); (M.-I.R.)
| | - Christophe Guichet
- Aix Marseille Univ, U. Toulon, CNRS, IM2NP (Institut Matériaux Microélectronique et Nanosciences de Provence), Campus St-Jérôme, 13397 Marseille CEDEX 20, France; (M.G.); (N.B.); (C.G.); (S.E.); (M.P.); (M.-I.R.)
| | - Stephanie Escoubas
- Aix Marseille Univ, U. Toulon, CNRS, IM2NP (Institut Matériaux Microélectronique et Nanosciences de Provence), Campus St-Jérôme, 13397 Marseille CEDEX 20, France; (M.G.); (N.B.); (C.G.); (S.E.); (M.P.); (M.-I.R.)
| | - Magali Putero
- Aix Marseille Univ, U. Toulon, CNRS, IM2NP (Institut Matériaux Microélectronique et Nanosciences de Provence), Campus St-Jérôme, 13397 Marseille CEDEX 20, France; (M.G.); (N.B.); (C.G.); (S.E.); (M.P.); (M.-I.R.)
| | - Cristian Mocuta
- Synchrotron SOLEIL, l’Orme des Merisiers, Saint-Aubin–BP 48, 91192 Gif-sur-Yvette, France;
| | - Marie-Ingrid Richard
- Aix Marseille Univ, U. Toulon, CNRS, IM2NP (Institut Matériaux Microélectronique et Nanosciences de Provence), Campus St-Jérôme, 13397 Marseille CEDEX 20, France; (M.G.); (N.B.); (C.G.); (S.E.); (M.P.); (M.-I.R.)
- ESRF, The European Synchrotron, ID01 Beamline, 71 Rue des Martyrs, 38043 Grenoble, France
| | - Rebecca Chahine
- University Grenoble Alpes, CEA (Commissariat à l’Energie Atomique et aux Énergies Alternatives), LETI (Laboratoire d’Electronique et des Technologies de l’Information), F-38000 Grenoble, France; (R.C.); (C.S.); (M.B.); (L.F.); (P.N.)
| | - Chiara Sabbione
- University Grenoble Alpes, CEA (Commissariat à l’Energie Atomique et aux Énergies Alternatives), LETI (Laboratoire d’Electronique et des Technologies de l’Information), F-38000 Grenoble, France; (R.C.); (C.S.); (M.B.); (L.F.); (P.N.)
| | - Mathieu Bernard
- University Grenoble Alpes, CEA (Commissariat à l’Energie Atomique et aux Énergies Alternatives), LETI (Laboratoire d’Electronique et des Technologies de l’Information), F-38000 Grenoble, France; (R.C.); (C.S.); (M.B.); (L.F.); (P.N.)
| | - Leila Fellouh
- University Grenoble Alpes, CEA (Commissariat à l’Energie Atomique et aux Énergies Alternatives), LETI (Laboratoire d’Electronique et des Technologies de l’Information), F-38000 Grenoble, France; (R.C.); (C.S.); (M.B.); (L.F.); (P.N.)
| | - Pierre Noé
- University Grenoble Alpes, CEA (Commissariat à l’Energie Atomique et aux Énergies Alternatives), LETI (Laboratoire d’Electronique et des Technologies de l’Information), F-38000 Grenoble, France; (R.C.); (C.S.); (M.B.); (L.F.); (P.N.)
| | - Olivier Thomas
- Aix Marseille Univ, U. Toulon, CNRS, IM2NP (Institut Matériaux Microélectronique et Nanosciences de Provence), Campus St-Jérôme, 13397 Marseille CEDEX 20, France; (M.G.); (N.B.); (C.G.); (S.E.); (M.P.); (M.-I.R.)
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17
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Behrens M, Lotnyk A, Bryja H, Gerlach JW, Rauschenbach B. Structural Transitions in Ge 2Sb 2Te 5 Phase Change Memory Thin Films Induced by Nanosecond UV Optical Pulses. MATERIALS (BASEL, SWITZERLAND) 2020; 13:E2082. [PMID: 32369916 PMCID: PMC7254329 DOI: 10.3390/ma13092082] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 04/26/2020] [Accepted: 04/28/2020] [Indexed: 11/16/2022]
Abstract
Ge-Sb-Te-based phase change memory alloys have recently attracted a lot of attention due to their promising applications in the fields of photonics, non-volatile data storage, and neuromorphic computing. Of particular interest is the understanding of the structural changes and underlying mechanisms induced by short optical pulses. This work reports on structural changes induced by single nanosecond UV laser pulses in amorphous and epitaxial Ge2Sb2Te5 (GST) thin films. The phase changes within the thin films are studied by a combined approach using X-ray diffraction and transmission electron microscopy. The results reveal different phase transitions such as crystalline-to-amorphous phase changes, interface assisted crystallization of the cubic GST phase and structural transformations within crystalline phases. In particular, it is found that crystalline interfaces serve as crystallization templates for epitaxial formation of metastable cubic GST phase upon phase transitions. By varying the laser fluence, GST thin films consisting of multiple phases and different amorphous to crystalline volume ratios can be achieved in this approach, offering a possibility of multilevel data storage and realization of memory devices with very low resistance drift. In addition, this work demonstrates amorphization and crystallization of GST thin films by using only one UV laser with one single pulse duration and one wavelength. Overall, the presented results offer new perspectives on switching pathways in Ge-Sb-Te-based materials and show the potential of epitaxial Ge-Sb-Te thin films for applications in advanced phase change memory concepts.
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Affiliation(s)
- Mario Behrens
- Department of Precision Surfaces, Leibniz Institute of Surface Engineering (IOM), Permoserstr 15, 04318 Leipzig, Germany; (H.B.); (J.W.G.); (B.R.)
| | - Andriy Lotnyk
- Department of Precision Surfaces, Leibniz Institute of Surface Engineering (IOM), Permoserstr 15, 04318 Leipzig, Germany; (H.B.); (J.W.G.); (B.R.)
- Laboratory of Infrared Materials and Devices, The Research Institute of Advanced Technologies, Ningbo University, Ningbo 315211, China
| | - Hagen Bryja
- Department of Precision Surfaces, Leibniz Institute of Surface Engineering (IOM), Permoserstr 15, 04318 Leipzig, Germany; (H.B.); (J.W.G.); (B.R.)
| | - Jürgen W. Gerlach
- Department of Precision Surfaces, Leibniz Institute of Surface Engineering (IOM), Permoserstr 15, 04318 Leipzig, Germany; (H.B.); (J.W.G.); (B.R.)
| | - Bernd Rauschenbach
- Department of Precision Surfaces, Leibniz Institute of Surface Engineering (IOM), Permoserstr 15, 04318 Leipzig, Germany; (H.B.); (J.W.G.); (B.R.)
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18
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Ren K, Xia M, Zhu S, Wang G, Xin T, Lv S, Song Z. Crystal-Like Glassy Structure in Sc-Doped BiSbTe Ensuring Excellent Speed and Power Efficiency in Phase Change Memory. ACS APPLIED MATERIALS & INTERFACES 2020; 12:16601-16608. [PMID: 32174106 DOI: 10.1021/acsami.0c00476] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Phase change memory (PCM) is regarded as a promising technology for storage-class memory and neuromorphic computing, owing to the excellent performances in operation speed, data retention, endurance, and controllable crystallization dynamics, whereas the high power consumption of PCM remains to be a short-board characteristic that limits its extensive applications. Here, Sc-doped Bi0.5Sb1.5Te3 has been proposed for high-speed and low-power PCM applications. An operation speed of 6 ns and a threshold current of 0.7 mA have been achieved in 190 nm Sc0.23Bi0.5Sb1.5Te3 PCM, which consumes lower power than GeSbTe and ScSbTe PCM. A good endurance of 5 × 105 has been achieved, which is attributed to the small volume change of 4% during phase change and a good homogeneity phase in the crystalline state. The structure of amorphous Sc0.23Bi0.5Sb1.5Te3 has been characterized by experimental and theoretical methods, showing the existence of a large amount of crystal-like structural factions, which can efficiently minimize the atomic movements required for crystallization and subsequently improve the operation speed and power efficiency. The low diffusivity of Sc and Bi at room temperature and the rapidly increased diffusivity of Bi at elevated temperatures are fundamental for the high data retention of 94 °C and the fast crystallization in Sc0.23Bi0.5Sb1.5Te3. The combination of high atomic mobility and minimized atomic movements during crystallization ensures the high speed and low power consumption of Sc0.23Bi0.5Sb1.5Te3 PCM, which can promote its application to energy-efficient systems, that is, AI chips and wearable electronics.
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Affiliation(s)
- Kun Ren
- College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou, Zhejiang 310018, China
- State Key Laboratory of Functional Materials for Informatics, Laboratory of Nanotechnology, Shanghai Institute of Micro-System and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
| | - Mengjiao Xia
- International Laboratory of Quantum Functional Materials of Henan, School of Physics and Engineering, Zhengzhou University, Zhengzhou 450001, China
| | - Shuaishuai Zhu
- ULVAC Research Center Suzhou Company, Ltd, Suzhou 215026, China
| | - Guoxiang Wang
- Research Institute of Advanced Technologies, Laboratory of Infrared Materials and Devices, Ningbo University, Ningbo 315211, Zhejiang, China
| | - Tianjiao Xin
- State Key Laboratory of Functional Materials for Informatics, Laboratory of Nanotechnology, Shanghai Institute of Micro-System and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
| | - Shilong Lv
- State Key Laboratory of Functional Materials for Informatics, Laboratory of Nanotechnology, Shanghai Institute of Micro-System and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
| | - Zhitang Song
- State Key Laboratory of Functional Materials for Informatics, Laboratory of Nanotechnology, Shanghai Institute of Micro-System and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China
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