마이크로전자및패키징학회지 (Journal of the Microelectronics and Packaging Society)

  • 제30권4호
  • /
  • Pages.32-43
  • /
  • 2023
  • /
  • 1226-9360(pISSN)
  • /
  • 2287-7525(eISSN)
한국마이크로전자및패키징학회 (The Korean Microelectronics and Packaging Society)
권호 표지
DOI QR코드

DOI QR Code

전이 금속 산화물 기반 Interface-type 저항 변화 특성 향상 연구 동향

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

  • 김동은 (연세대학교 신소재공학과) ;
  • 김건우 (연세대학교 신소재공학과) ;
  • 김형남 (연세대학교 신소재공학과) ;
  • 박형호 (연세대학교 신소재공학과)
  • Dong-eun Kim (Department of Materials Science and Engineering, Yonsei University) ;
  • Geonwoo Kim (Department of Materials Science and Engineering, Yonsei University) ;
  • Hyung Nam Kim (Department of Materials Science and Engineering, Yonsei University) ;
  • Hyung-Ho Park (Department of Materials Science and Engineering, Yonsei University)
  • 투고 : 2023.12.22
  • 심사 : 2023.12.30
  • 발행 : 2023.12.30
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

저항 변화 메모리 소자(RRAM)는 저항 변화 특성을 기반으로 빠른 동작 속도, 간단한 소자 구조 및 고집적 구조의 구현을 통해 많은 양의 데이터를 효율적으로 처리할 수 있는 차세대 메모리 소자로 주목받고 있다. RRAM의 작동원리 중 하나로 알려진 interface type의 저항 변화 특성은 forming process를 수반하지 않고 소자 크기를 조절하여 낮은 전류에서 구동이 가능하다는 장점을 갖는다. 그 중에서도 전이 금속 산화물 기반 RRAM 소자의 경우, 정확한 물질의 조성 조절 방법과 소자의 신뢰성 및 안정성과 같은 메모리 특성을 향상시키기 위해 다양한 연구가 진행 중에 있다. 본 논문에서는 이종 원소의 도핑, 다층 박막의 형성, 화학적 조성 조절 및 표면 처리 등의 방법을 이용하여 interface type 저항 변화 특성의 저하를 방지하고 소자 특성을 향상시키기 위한 다양한 방법을 소개하고자 한다. 이를 통해 향상된 저항 변화 특성을 기반으로 한 고효율 차세대 비휘발성 메모리 소자의 구현 가능성을 제시한다.

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.

키워드

과제정보

이 성과는 정부(과학기술정보통신부)의 재원으로 한국연구재단의 지원을 받아 수행된 연구임(No. RS-2023-00208801).

참고문헌

  1. 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).
  2. 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). https://doi.org/10.1038/s41586-020-2782-y
  3. 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).
  4. 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). https://doi.org/10.1038/s41565-020-0655-z
  5. 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).
  6. K. Itoh, T. Watanabe, S. I. Kimura, and T. Sakata, "Reviews and prospects of high-density RAM technology", IEEE, 1, 13-22 (2000).
  7. 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).
  8. 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).
  9. W. Banerjee, "Challenges and applications of emerging nonvolatile memory devices", Electronics, 9(6), 1029 (2020).
  10. 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).
  11. 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).
  12. 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). https://doi.org/10.1186/s11671-019-3237-y
  13. 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). https://doi.org/10.1002/inf2.12077
  14. 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). https://doi.org/10.1016/j.mattod.2017.07.007
  15. 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).
  16. 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).
  17. 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).
  18. 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). https://doi.org/10.1007/s10853-018-2134-6
  19. Y. Wu, X. Wang, and W. D. Lu, "Dynamic resistive switching devices for neuromorphic computing", Semicond. Sci. Technol., 37(2), 024003 (2021).
  20. 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). https://doi.org/10.1080/02564602.2019.1629341
  21. 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). https://doi.org/10.1039/D0NA00100G
  22. 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).
  23. 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). https://doi.org/10.1186/s11671-019-3237-y
  24. 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).
  25. 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). https://doi.org/10.1166/jnn.2019.16781
  26. 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). https://doi.org/10.1109/LED.2019.2961408
  27. 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). https://doi.org/10.1016/j.mee.2015.03.027
  28. 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).
  29. 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).
  30. 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). https://doi.org/10.1021/acsaelm.0c00128
  31. 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).
  32. A. Prakash and H. Hwang, "Multilevel cell storage and resistance variability in resistive random access memory", Phys. Sci. Rev., 1(6), 20160010 (2016).
  33. 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).
  34. 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). https://doi.org/10.1109/TED.2008.2010584
  35. 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). https://doi.org/10.1109/LED.2011.2104936
  36. 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). https://doi.org/10.1016/j.nanoen.2018.09.029
  37. 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).
  38. E. Lim and R. Ismail, "Conduction mechanism of valence change resistive switching memory: A survey.", Electronics, 4(3), 586-613 (2015). https://doi.org/10.3390/electronics4030586
  39. 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). https://doi.org/10.1109/TED.2020.3022005
  40. 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). https://doi.org/10.1021/acsami.9b12931
  41. 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).
  42. 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). https://doi.org/10.1109/LED.2011.2147274
  43. 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).
  44. 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). https://doi.org/10.1080/02564602.2019.1629341
  45. 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). https://doi.org/10.1186/s11671-019-3237-y
  46. 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).
  47. 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). https://doi.org/10.1109/ACCESS.2020.3046300
  48. 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).
  49. 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). https://doi.org/10.1002/adma.201001872
  50. 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). https://doi.org/10.1063/1.1812580
  51. 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).
  52. 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).
  53. 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).
  54. 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).
  55. 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).
  56. 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).
  57. 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).
  58. 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). https://doi.org/10.1039/C8FD00127H
  59. 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). https://doi.org/10.1021/acsami.2c12247
  60. 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). https://doi.org/10.1109/LED.2018.2821162
  61. 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). https://doi.org/10.1016/j.microrel.2015.04.002
  62. 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). https://doi.org/10.1021/acsami.0c06476
  63. 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). https://doi.org/10.1021/acsnano.9b02108
  64. 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).
  65. 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).
  66. 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).
  67. 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).
  68. 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).
  69. H. Lee, "The Latest Trend and Issues of Anion-based Memristor", J. Microelectron. Electron. Packag., 26(11), 1-7 (2019).
  70. 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).
  71. 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).
  72. 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).
  73. 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).
  74. 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).
  75. 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).
  76. 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).
  77. 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).
  78. 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).
  79. 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). https://doi.org/10.1002/adfm.201400064
  80. 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). https://doi.org/10.1016/j.sse.2013.06.011
  81. 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). https://doi.org/10.1021/acsami.2c03451
  82. 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).
  83. 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).
  84. A. Sawa, "Resistive switching in transition metal oxide", Mater Today., 11(6), 28 (2008).
  85. 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).
  86. 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).
  87. 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). https://doi.org/10.1021/acsami.2c12296
  88. 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).
  89. 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).
  90. 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). https://doi.org/10.1016/j.jallcom.2017.11.267
  91. 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). https://doi.org/10.1016/j.apsusc.2013.03.122
  92. 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). https://doi.org/10.1021/acsami.5b01080