2024

Vol.31 No.2

Editorial Office

Review

  • Journal of the Microelectronics and Packaging Society
  • Volume 30(4); 2023
  • Article

Review

Journal of the Microelectronics and Packaging Society 2023;30(4):32-43. Published online: Feb, 20, 2024

Research Trends on Interface-type Resistive Switching Characteristics in Transition Metal Oxide

  • Dong-eun Kim, Geonwoo Kim, Hyung Nam Kim, and Hyung-Ho Park
    Department of Materials Science and Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, South Korea
Corresponding author E-mail: hhpark@yonsei.ac.kr
Abstract

Resistive Random Access Memory (RRAM), based on resistive switching characteristics, is emerging as a next-generation memory device capable of efficiently processing large amounts of data through its fast operation speed, simple device structure, and high-density implementation. Interface type resistive switching offer the advantage of low operation currents without the need for a forming process. Especially, for RRAM devices based on transition metal oxides, various studies are underway to enhance the memory characteristics, including precise material composition control and improving the reliability and stability of the device. In this paper, we introduce various methods, such as doping of heterogeneous elements, formation of multilayer films, chemical composition adjustment, and surface treatment to prevent degradation of interface type resistive switching properties and enhance the device characteristics. Through these approaches, we propose the feasibility of implementing high-efficient next-generation non-volatile memory devices based on improved resistive switching properties.

Keywords Interface-type, RRAM, Resistive switching, Transition metal oxide

REFERENCES
  • S. Petrenko, "Big Data Technologies for Monitoring of Computer Security: A Case Study of the Russian Federation", Springer International Publishing, 1-249, New York (2018).
  • Y. Zhang, P. Qu, Y. Ji, W. Zhang, G. Gao, G. Wang, and L. Shi, "A system hierarchy for brain-inspired computing", Nat., 586(7829), 378-384 (2020).
  • Y. Zhong, J. Tang, X. Li, B. Gao, H. Qian, and H. Wu, "Dynamic memristor-based reservoir computing for high-efficiency temporal signal processing", Nat. commun., 12(1), 408 (2021).
  • A. Sebastian, M. Le Gallo, R. Khaddam-Aljameh, and E. Eleftheriou, "Memory devices and applications for in-memory computing", Nat. Nanotechnol., 15(7), 529-544 (2020).
  • K. Huang, Y. Yan, and L. Huang, "Revisiting persistent hash table design for commercial non-volatile memory", 2020 Design, Automation & Test in Europe Conference & Exhibition (DATE), France, pp. 708-713, IEEE (2020).
  • K. Itoh, T. Watanabe, S. I. Kimura, and T. Sakata, "Reviews and prospects of high-density RAM technology", IEEE, 1, 13-22 (2000).
  • A. Durgesh and S. L. Tripathi, "Design of Low-Power DRAM Cell Using Advanced FET Architectures", Electrical and Electronic Devices, Circuits, and Materials: Technological Challenges and Solutions, S. L. Tripathi, P. A. Alvi and U. Subramaniam, pp. 119-132, Wiley, New Jersey (2021).
  • M. K. Kim, I. J. Kim, and J. S. Lee, "CMOS-compatible ferroelectric NAND flash memory for high-density, low-power, and high-speed three-dimensional memory", Sci. Adv., 7(3), 1341 (2021).
  • W. Banerjee, "Challenges and applications of emerging nonvolatile memory devices", Electronics, 9(6), 1029 (2020).
  • S. S. Kim, S. K. Yong, W. Kim, S. Kang, H. W. Park, K. J. Yoon, and C. S. Hwang, "Review of semiconductor flash memory devices for material and process issues", Adv. Mater., 35(43), 2200659 (2023).
  • S. Yu and P. Y. Chen, "Emerging memory technologies: Recent trends and prospects", IEEE Conf. Electron Devices Solid-State Circuits, 8(2), 43-56 (2016).
  • F. Zahoor, T. Z. Azni Zulkifli, and F. A. Khanday, "Resistive random access memory (RRAM): an overview of materials, switching mechanism, performance, multilevel cell (MLC) storage, modeling, and applications", Nanoscale Res. Lett., 15, 1-26 (2020).
  • Z. Zhang, Z. Wang, T. Shi, C. Bi, F. Rao, Y. Cai, and P. Zhou, "Memory materials and devices: From concept to application", InfoMat., 2(2), 261-290 (2020).
  • S. Bhatti, R. Sbiaa, A. Hirohata, H. Ohno, S. Fukami, and S. N. Piramanayagam, "Spintronics based random access memory: a review", Mater. Today., 20(9), 530-548 (2017).
  • H. Wang and X. Yan, "Overview of resistive random access memory (RRAM): Materials, filament mechanisms, performance optimization, and prospects", Phys. Status Solidi RRL., 13(9), 1900073 (2019).
  • J. Yin, W. Liao, Y. Zhang, J. Jiang, and C. Chen, "An 8kb RRAM-based nonvolatile SRAM with Pre-decoding and fast storage/restoration time", Appl. Sci., 13(1), 531 (2022).
  • V. Milo, C. Zambelli, P. Olivo, E. Perez, M. K Mahadevaiah, O. G. Ossorio, and D. Ielmini, "Multilevel HfO2-based RRAM devices for low-power neuromorphic networks", APL Mater., 7(8) (2019).
  • X. Hong, D. J. Loy, P. A. Dananjaya, F. Tan, C. Ng, and W. Lew, "Oxide-based RRAM materials for neuromorphic computing" J. Mater. Sci., 53, 8720-8746 (2018).
  • Y. Wu, X. Wang, and W. D. Lu, "Dynamic resistive switching devices for neuromorphic computing", Semicond. Sci. Technol., 37(2), 024003 (2021).
  • V. Gupta, S. Kapur, S. Saurabh, and A. Grover, "Resistive random access memory: a review of device challenges" IETE Tech. Rev., 37(4), 377-390 (2020).
  • L. Shi, G. Zheng, B. Tian, B. Dkhil, and C. Duan, "Research progress on solutions to the sneak path issue in memristor crossbar arrays", Nanoscale Adv., 2(5), 1811-1827 (2020).
  • K. Jeon, J. Kim, J. J. Ryu, S. J. Yoo, C. Song, M. K. Yang, D. S. Jeong, and G. H. Kim, "Self-rectifying resistive memory in passive crossbar arrays", Nat. Commun., 12(1), 2968 (2021).
  • F. Zahoor, T. Z. A. Zulkifli, and F. A. Khanday, "Resistive random access memory (RRAM): an overview of materials, switching mechanism, performance, multilevel cell (MLC) storage, modeling, and applications", Nanoscale Res. Lett.,15, 1-26 (2020).
  • Y. Qi, C. Z. Zhao, C. Liu, Y. Fang, J. He, T. Luo, and C. Zhao, "Comparisons of switching characteristics between Ti/Al2O3/Pt and TiN/Al2O3/Pt RRAM devices with various compliance currents" Semicond. Sci. Technol., 33(4), 045003 (2018).
  • C. H. Cheng, A. Chin, and H. H. Hsu, "Forming-Free SiGeOx/TiOy Resistive Random Access Memories Featuring Large Current Distribution Windows", J. Nanosci. Nanotechnol., 19(12), 7916-7919 (2019).
  • K. J. Zhou, T. C. Chang, C. Y. Lin, C. K. Chen, Y. T. Tseng, H. X. Zheng, and S. M. Sze, "Abnormal high resistive state current mechanism transformation in Ti/HfO2/TiN resistive random access memory", IEEE Electron Device Let., 41(2), 224-227 (2019).
  • C. L. Lin, C. C. Tang, S. C. Wu, P. C. Juan, and T. K. Kang, "Impact of oxygen composition of ZnO metal-oxide on unipolar resistive switching characteristics of Al/ZnO/Al resistive RAM (RRAM)", Microelectron Eng., 136, 15-21 (2015).
  • S. Y. Wang, D. Y. Lee, T. Y. Huang, J. W. Wu, and T. Y. Tseng, "Controllable oxygen vacancies to enhance resistive switching performance in a ZrO2-based RRAM with embedded Mo layer", Nanotechnol., 21(49), 495201 (2010).
  • B. R. Lee, J. H. Park, and T. G. Kim, "Micro-light-emitting diode with n-GaN/NiO/Au-based resistive-switching electrode for compact driving circuitry", J. Alloys. Compd., 823, 153762 (2020).
  • T. S. Lee, N. J. Lee, H. Abbas, H. H. Lee, T. S. Yoon, and C. J. Kang, "Compliance current-controlled conducting filament formation in tantalum oxide-based RRAM devices with different top electrodes", ACS Appl. Electron. Mater., 2(4), 1154-1161 (2020).
  • G. Bersuker, D. Gilmer, D. Veksler, P. Kirsch, L. Vandelli, A. Padovani, L. Larcher, K. McKenna, A. Shluger, V. Iglesias, M. Porti, and M. Nafria, "Metal oxide resistive memory switching mechanism based on conductive filament properties", J. Appl. Phys. 110, 124518 (2011).
  • A. Prakash and H. Hwang, "Multilevel cell storage and resistance variability in resistive random access memory", Phys. Sci. Rev., 1(6), 20160010 (2016).
  • M. Wu, J. Chen, Y. Ting, C. Huang, and W. Wu, "A novel high-performance and energy-efficient RRAM device with multi-functional conducting nanofilaments", Nano Energy, 82, 105717 (2021).
  • U. Russo, D. Ielmini, C. Cagli, and A. L. Lacaita, "Self-accelerated thermal dissolution model for reset programming in unipolar resistive-switching memory (RRAM) devices", IEEE Trans. Electron Devices, 56(2), 193-200 (2009).
  • Y. Syu, T. Chang, T. Tsai, Y. Hung, K. Chang, M. Tsai, M. Kao, and S. Sze, "Redox Reaction Switching Mechanism in RRAM Device with Pt/CoSiOx/TiN Structure", IEEE Electron Device Lett., 32(4), 545-547 (2011).
  • C. Chang, J. Chen, G. Huang, T. Lin, K. Tai, C. Huang, P. Yeh, and W. Wu, "Revealing conducting filament evolution in low power and high reliability Fe3O4/Ta2O5 bilayer RRAM", Nano Energy, 53, 871-879 (2018).
  • X. Hong, P. Dananjaya, S. Krishnia, W. Gan, D. Loy, F. Tan, C. Ng, and W. Lew, "A novel geometry of ECM-based RRAM with improved variability", J. Phys. D., (2018).
  • E. Lim and R. Ismail, "Conduction mechanism of valence change resistive switching memory: A survey.", Electronics, 4(3), 586-613 (2015).
  • W. Wang, Y. Li, W. Yue, S. Gao, C. Zhang, Z. Chen, and Y. Chen, "Study on multilevel resistive switching behavior with tunable ON/OFF ratio capability in forming-free ZnO QDs-based RRAM", IEEE Trans. Electron Devices, 67(11), 4884-4890 (2020).
  • X. Cao, Y. Han, J. Zhou, W. Zuo, X. Gao, L. Han, X. Pang, L. Zhang, Y. Liu, and S. Cao, "Enhanced switching ratio and long-term stability of flexible RRAM by anchoring polyvinylammonium on perovskite grains", ACS Appl. Mater. Interfaces, 11(39), 35914-35923 (2019).
  • H. Wang and X. Yan, "Overview of resistive random access memory (RRAM): Materials, filament mechanisms, performance optimization, and prospects", Phys. Status Solidi RRL, 13(9), 1900073 (2019).
  • J. Shin, J. Park, J. Lee, S. Park, S. Kim, W. Lee, I. Kim, D. Lee, and H. Hwang, "Effect of program/erase speed on switching uniformity in filament-type RRAM", IEEE Electron Device Lett., 32(7), 958-960 (2011).
  • H. Lv, M. Yin, P. Zhou, T. Tang, B. Chen, Y. Lin, A. Bao, and M. Chi, "Improvement of endurance and switching stability of forming-free CuxO RRAM", pp. 52-53, IEEE (2008).
  • V. Gupta, S. Kapur, S. Saurabh, and A. Grover, "Resistive random access memory: a review of device challenges", IETE Tech. Rev., 37(4), 377-390 (2020).
  • F. Zahoor, T. Zulkifli, and F. Khanday, "Resistive random access memory (RRAM): an overview of materials, switching mechanism, performance, multilevel cell (MLC) storage, modeling, and applications", Nanoscale Res. Lett., 15, 1-26 (2020).
  • M. Ismail, C. Mahata, and S. Kim, "Electronic synaptic plasticity and analog switching characteristics in Pt/TiOx/AlOx/AlTaON/TaN multilayer RRAM for artificial synapses", Appl. Surf. Sci., 599, 153906 (2022).
  • Y. Choi, M. Kim, S. Bang, T. Kim, D. Lee, K. Hong, C. Kim, S. Kim, S. Cho, and B. Park, "Insertion of Ag layer in TiN/SiNx/TiN RRAM and its effect on filament formation modeled by monte carlo simulation", IEEE Access, 8, 228720-228730 (2020).
  • D. Niu, C. Xu, N. Muralimanohar, N. Jouppi, and Y. Xie, "Design trade-offs for high density cross-point resistive memory", pp. 209-214 (2012).
  • R. Muenstermann, T. Menke, R. Dittmann, and R. Waser, "Coexistence of Filamentary and Homogeneous Resistive Switching in Fe-Doped SrTiO3 Thin-Film Memristive Devices", Adv. Mater., 22(43), 4819-4822 (2010).
  • A. Sawa, T. Fujii, M. Kawasaki, and Y. Tokura, "Hysteretic current-voltage characteristics and resistance switching at a rectifying Ti∕ Pr0.7Ca0.3MnO3 interface", Appl. Phys. Lett., 85(18), 4073-4075 (2004).
  • A. Gismatulin, G. Kamaev, V. Kruchinin, V. Gritsenko, O. Orlov, and A. Chin, "Charge transport mechanism in the forming-free memristor based on silicon nitride", Sci. Rep., 11(1), 2417 (2021).
  • Y. Wang, M. Kim, C. Lee, A. S. Chabungbam, J. Kim, J. Lee, H. S. Lee, Q. Shao, H. Sohn, and H. H. Park, "Electric field induced Mott transition and bipolar resistive switching in La2-Ti2O7-x thin film", Appl. Mater. Today, 26, 101395 (2022).
  • T. Hennen, D. Bedau, J. Rupp, C. Funck, S. Menzel, M. Grobis, R. Waser, and D. Wouters, "Forming-free Mott-oxide threshold selector nanodevice showing s-type NDR with high endurance (> 1012 cycles), excellent Vth stability (5 %), fast (< 10 ns) switching, and promising scaling properties", IEEE Int. Electron Devices Meet., 8614618 (2018).
  • H. Lee, P. Chen, T. Wu, Y. Chen, C. Wang, P. Tzeng, C. Lin, F. Chen, C. Lien, and M. Tsai, "Low power and high speed bipolar switching with a thin reactive Ti buffer layer in robust HfO2 based RRAM", IEEE Int. Electron Devices Meet., pp. 1-4 (2008).
  • N. Das, S. Oh, J. Rani, S. Hong, and J. Jang, "Multilevel bipolar electroforming-free resistive switching memory based on silicon oxynitride", Appl. Sci., 10(10), 3506 (2020).
  • R. Tominov, Z. Vakulov, N. Polupanov, A. Saenko, V. Avilov, O. Ageev, and V. Smirnov, "Nanoscale-resistive switching in forming-free zinc oxide memristive structures", Nanomater., 12(3), 455 (2022).
  • J. Lee, J. Shin, D. Lee, W. Lee, S. Jung, M. Jo, J. Park, K. Biju, S. Kim, S. Park, and H. Hwang, "Diode-less nano-scale ZrOx/HfOx RRAM device with excellent switching uniformity and reliability for high-density cross-point memory applications", IEEE Int. Electron Devices Meet., 5703393 (2010).
  • K. Moon, S. Lim, J. Park, C. Sung, S. Oh, J. Woo, J. Lee, and H. Hwang, "RRAM-based synapse devices for neuromorphic systems", Faraday Discuss., 213, 421-451 (2019).
  • J. Kwon, Y. Song, J. Kim, S. Chun, G. Kim, G. Noh, J. Kwak, S. Hur, C. Kang, D. Jeong, S. Oh, and J. Yoon, "Surface-Dominated HfO2 Nanorod-Based Memristor Exhibiting Highly Linear and Symmetrical Conductance Modulation for High-Precision Neuromorphic Computing", ACS Appl. Mater. Interfaces, 14, 39, 44550-44560 (2022).
  • Q. Luo, X. Zhang, Y. Hu, T. Gong, X. Xu, P. Yuan, H. Ma, D. Dong, H. Lv, S. Long, Q. Liu, and M. Liu, "Self-rectifying and forming-free resistive-switching device for embedded memory application", IEEE Electron Device Lett., 39(5), 664-667 (2018).
  • C. Chou, B. Hudec, C. Hsu, W. Lai, C. Chang, and T. Hou, "Crossbar array of selector-less TaOx/TiO2 bilayer RRAM", Microelectron. Reliab., 55(11), 2220-2223 (2015).
  • X. Li, J. Yang, H. Ma, Y. Liu, Z. Ji, W. Huang, X. Ou, W. Zhang, and H. Lu, "Atomic layer deposition of Ga2O3/ZnO composite films for high-performance forming-free resistive switching memory", ACS Appl. Mater. Interfaces, 12(27), 30538-30547 (2020).
  • D. S. Kim, Y. D. Yun, J. S. Kim, Y. B. Kim, S. H. Jung, N. G. Deshpande, H. S. Lee, and H. K. Cho, "Electrochemically assembled Cu2O nanoparticles using crystallographically anisotropic functional metal ions and highly expeditious resistive switching via nanoparticle coarsening", ACS Nano, 13(5), 5987-5998 (2019).
  • D. S. Hyeon, G. Jang, S. Min, and J. P. Hong, "Highly Stable Forming-Free Bipolar Resistive Switching in Cu Layer Stacked Amorphous Carbon Oxide: Transition between C-C Bonding Complexes", Adv. Electron. Mater., 8(2), 2100660 (2021).
  • H. Zhang, B. Gao, B. Sun, G. Chen, L. Zeng, L. Liu, X. Liu, J. Lu, R. Han, J. Kang, and B. Yu, "Ionic doping effect in ZrO2 resistive switching memory", Appl. Phys. Lett., 96(12) (2010).
  • S. Kim, S. Choi, J. Lee, and W. D. Lu, "Tuning Resistive switching characteristics of Tantalum Oxide Memristors through Si Doping", ACS Nano, 8(10), 10262 (2014).
  • H. Zhang, L. Liu, B. Gao, Y. Qiu, X. Liu, J. Lu, R. Han, J. Kang, and B. Yu, "Gd-doping effect on performance of HfO2 based resistive switching memory devices using implantation approach", Appl. Phys. Lett., 98(4), (2011).
  • R. Schmitt, J. Spring, R. Korobko, and J. L. M. Rupp, "Design of oxygen vacancy configuration for memristive systems", ACS Nano, 11(9), 8881 (2017).
  • H. Lee, "The Latest Trend and Issues of Anion-based Memristor", J. Microelectron. Electron. Packag., 26(11), 1-7 (2019).
  • K. Jeon, J. Kim, J. J. Ryu, S. Yoo, C. Song, M. K. Yang, D. S. Jeong, and G. H. Kim, "Self-rectifying resistive memory in passive crossbar arrays", Nature communications, 12(1), 2968 (2021).
  • M. Kim, K. Kang, Y. Wang, A. S. Chabungbam, D. Kim, H. N. Kim, and H. -H. Park, "Resistive Switching Properties of N and F co-doped ZnO", J. Microelectron. Electron. Packag., 29(2), 53-58 (2022).
  • S. E. Kim, J. G. Lee, L. Ling, S. E. Liu, H. K. Lim, V. K. Sangwan, and H. S. Lee, "Sodium-Doped Titania Self-Rectifying Memristors for Crossbar Array Neuromorphic Architectures", Adv Mater., 34(6), 2106913 (2022).
  • M. Kim, Y. Wang, D. E. Kim, Q. Shao, H. S. Lee, and H. H. Park, "Resistive switching properties for fluorine doped titania fabricated using atomic layer deposition", APL Mater., 10(3) (2022).
  • J. N. Huang, H. M. Huang, Y. Xiao, T. Wang, and X. Guo, "Memristive devices based on Cu-doped NbOx films with large self-rectifying ratio", Solid State Ion., 369, 115732 (2021).
  • W. Liu, L. Gao, K. Xu, and F. Ma, "Impact of ultrathin Al2O3 interlayers on resistive switching in TiOx thin films deposited by atomic layer deposition", J. Vac. Sci. Technol. B., 35(4) (2017).
  • L. Wang, X. Qian, Y. Cao, Z. Cao, G. Fang, A. Li, and D. Wu, "Excellent reistive switching properties of atomic layer-deposited Al2O3/HfO2/Al2O3 trilayer structure for non-volatile memory applications", Nanoscale Res. Lett., 10, 1 (2015).
  • S. Rehman, H. Kim, M. F. Khan, J. Hur, A. D. Lee, and D. Kim, "Tuning of ionic mobility to improve the resistive switching behavior of Zn-doped CeO2", Sci. Rep., 9(1), 19387 (2019).
  • S. Siegel, C. Baeumer, A. Gutsche, M. V. Witzleben, R. Waser, S. Menzel, and R. Dittmann, "Trade-Off between Data Retention and Switching Speed in Resistive Switching ReRAM Devices", Adv. Electron. Mater., 7(1) 2000815 (2021).
  • J. Yoon, S. J. Song, I. Yoo, J. Y. Seok, K. J. Yoon, D. E. Kwon, T. H. Park, and C. S. Hwang, "Highly uniform, electroforming-free, and self-rectifying resistive memory in the Pt/Ta2O5/HfO2-x/TiN structure", Adv. Funct. Mater., 24(32), 5086-5095 (2014).
  • H. Zhao, H. Tu, F. Wei, X. Zhang, Y. Xiong, and J. Du, "The enhancement of unipolar resistive switching behavior via an amorphous TiOx layer formation in Dy2O3-based forming-free RRAM, Solid State Electronics", 89, 12-16 (2013).
  • Y. Wang, M. Kim, M. A. Rehman, A. S. Chabungbam, D. E. Kim, H. S. Lee, and H. H. Park, "Bipolar Resistive Switching in Lanthanum Titanium Oxide and an Increased On/Off Ratio Using an Oxygen-Deficient ZnO Interlayer", ACS Appl. Mater. Interfaces, 14(15), 17682-17690 (2022).
  • M. Ismail, C. Mahata, and S. Kim, "Forming-free Pt/Al2O3/HfO2/HfAlOx/TiN memristor with controllable multilevel resistive switching and neuromorphic characteristics for artificial synapse", J. Alloys. Compd., 892, 162141 (2022).
  • G. Kim, S. Son, H. Song, J. B. Jeon, J. Lee, W. H. Cheong, S. Choi, and K. M. Kim, "Retention Secured Nonlinear and Self-Rectifying Analog Charge Trap Memristor for Energy-Efficient Neuromorphic Hardware", Adv. Sci., 10, 2205654 (2023).
  • A. Sawa, "Resistive switching in transition metal oxide", Mater Today., 11(6), 28 (2008).
  • S. Kim and H. Lee, "Electric-field Assisted Photochemical Metal Organic Deposition for Forming-less Resistive Switching Device", J. Microelectron. Electron. Packag., 27(4), 77-81 (2020).
  • Y. Wang, M. Kim, A. S. Chabungbam, D. E. Kim, Q. Shao, I. Kymissis, and H. H. Park, "Relationship between resistive switching and Mott transition in atomic layer deposition prepared La2Ti2O7-x thin film", Scr. Mater., 222, 115050 (2023).
  • M. Kim, M. A. Rehman, D. Lee, Y. Wang, D. H. Lim, M. F. Khan, H. Choi, Q. Y. Shao, J. Suh, H. S. Lee, and H. H Park, "Filamentary and Interface-Type Memristors Based on Tantalum Oxide for Energy-Efficient Neuromorphic Hardware", ACS Appl. Mater. Interfaces, 14, 44561-44571 (2022).
  • J. C. Gonzalez-Rosillo, M. Balaish, Z. D. Hood, N. Nadkarni, D. Fraggedakis, K. J. Kim, and J. L. Rupp, "Lithium-battery anode gains additional functionality for neuromorphic computing through metal-insulator phase separation", Adv. Mater., 32(9), 1907465 (2020).
  • H. Lv, X. Xu, H. Liu, R. Liu, Q. Liu, W. Banerjee, H. Sun, S. Long, L. Li, and M. Liu, "Evolution of conductive filament and its impact on reliability issues in oxide-electrolyte based resistive random access memory", Sci. Rep., 5(1), 7764 (2015).
  • B. Ku, Y. Abbas, A. S. Sokolov, and C. Choi, "Interface engineering of ALD HfO2-based RRAM with Ar plasma treatment for reliable and uniform switching behaviors", J. Alloys Compd., 735, 1181-1188 (2018).
  • J. C. Wang, Y. R. Ye, C. S. Lai, C. T. Lin, H. C. Lu, C. I. Wu, and P. S. Wang, "Characterization of gadolinium oxide thin films with CF4 plasma treatment for resistive switching memory applications", Appl. Surf. Sci., 276, 497-501 (2013).
  • Y. Sun, X. Yan, X. Zheng, Y. Liu, Y. Zhao, Y. Shen, Q. Liao, and Y. Zhang, "High On-Off Ratio Improvement of ZnO-Based Forming-Free Memristor by Surface Hydrogen Annealing", ACS Appl. Mater. Interfaces, 7, 7382-7388 (2015).