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研究生： 洪士哲
Hung, Shih-Che
論文名稱： 氧化鎳應用於電阻式記憶體特性之研究
Characteristics of nickel oxide thin films for resistance random access memory application
指導教授： 陳貞夙
Chen, Jen-Sue
學位類別： 碩士
Master
系所名稱： 工學院 - 材料科學及工程學系
Department of Materials Science and Engineering
論文出版年： 2008
畢業學年度： 96
語文別： 中文
論文頁數： 121
中文關鍵詞： 電阻式記憶體 、氧化鎳
外文關鍵詞： RRAM, NiO
相關次數： 點閱：70  下載：18 
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    • 　　本實驗利用鎳金屬靶進行反應性射頻磁控濺鍍製備結晶性氧化鎳薄膜，應用於電阻式記憶體。觀察不同的濺鍍時間、以及氧氣氛退火處理對氧化鎳之基本材料特性之影響，以及製備電阻式記憶體（RRAM）元件觀察不同膜厚氧化鎳層之Al/NiO/Pt結構和在電極與氧化鎳層之間夾進一鎳薄層（Al/Ni-NiO-Ni/Pt結構）對電阻轉換特性的影響，並進一步試圖了解電阻轉換效應的工作機制來源。
    　　在材料基本分析、以及對RRAM元件做電性量測方面，本實驗利用表面粗度儀來得知RRAM元件各層膜厚；利用電子微探儀進行氧化鎳薄膜成份分析；利用低掠角X光繞射分析儀進行氧化鎳薄膜結晶結構分析；利用四點探針以及霍爾量測系統進行氧化鎳薄膜導電性質量測；最後，利用精密半導體參數分析儀進行RRAM元件之電性量測分析。
    　　實驗結果顯示，利用鎳金屬靶進行反應性射頻磁控濺鍍所製備之氧化鎳薄膜，不論為初鍍膜或經過退火處理，皆具有結晶性，屬於P-type半導體，且其氧原子對鎳原子比值皆大於一。經過氧氣氛500℃退火處理後，其比值會較接近一，且其電阻率和載子遷移率皆上升，而載子濃度會下降。推論這是由於退火時氧化鎳薄膜中原本在格隙位置上的氧原子釋出，氧化鎳薄膜趨於緻密化，此現象使缺陷減少，然後造成載子濃度下降，電阻率上升。
    　　而將氧化鎳薄膜應用於RRAM元件上，不論為何種條件，皆可以觀察到電阻轉換的現象。在電阻轉換成功率方面，退火前之試片似乎優於退火後之試片。在記憶持久性測試方面，對上電極施予+0.1V的偏壓600秒後，其高電阻態和低電組態的電流值皆能維持。在Al/NiO/Pt結構中，比較不同氧化鎳膜厚之RRAM元件，可以發現氧化鎳膜厚128nm的RRAM其IRESET、VSET和on/off ratio會比膜厚53nm的RRAM為大。若將其低電阻態之電壓電流曲線做導電機制分析，其屬於歐姆效應；而高電阻態之導電機制屬於熱發射效應。而在Al/Ni-NiO-Ni/Pt結構中，未退火之試片之低電阻態導電機制會偏離歐姆效應而偏向空間電荷限制電流的行為，而退火後試片之低電阻態導電機制仍會遵守歐姆行為；而高電阻態之導電機制仍然屬於熱發射效應。

    In this study, thin films of nickel oxide (NiO) are applied in the resistance random access memory (RRAM) devices, and the NiO films were deposited by reactive sputtering from Ni target. Effects of spattering time and annealing in oxygen ambient on the material characteristic of NiO, and the resistive switching behaviors of Al/NiO/Pt RRAM devices are investigated. In addition, an ultra thin Ni layer is interposed between electrode layer and NiO (Al/Ni-NiO-Ni/Pt structure) to find its influences on the RRAM characteristics, in order to understand the mechanism of resistive switching.
    Regarding to material characteristics of NiO and the electrical properties of RRAM devices, thickness of each layer in RRAM devices was measured by using Alpha-step profilometer. Electron probe x-ray microanalyzer (EPMA) was utilized to determine the composition of NiO. The crystal structure of NiO films was identified by grazing incident angle x-ray diffraction (GIAXRD). Carrier concentration, mobility and resistivity of NiO films were determined by Hall measurement. Film resistivity of NiO films was also determined by four-point probe. The I-V curve and retention test of RRAM devices were measured by precision semiconductor parameter analyzer (Agilent 4156C).
    Experimental results reveal that all NiO films, before or after annealing, are polycrystalline, and the NiO is a P-type semiconductor. The oxygen/Ni atomic ratio of as-deposited films is larger than one. After annealing at 500℃ in oxygen ambient, the oxygen/Ni atomic ratio and carrier concentration are decreased, and the resistivity and carrier mobility are increased, possibly because the oxygen atoms may evaporate in form of O2 gas and the NiO films become denser. Therefore, annealy shall decrease the defects in NiO. As a result, the carrier concentration of NiO is decreased and the resistivity is increased.
    In RRAM devices, resistive switching phenomenon can be seen in all structures. However, the probability of successful resistive switching is greater for the non-annealed samples than the annealed samples. Current stress test indicates that the on-state and off-state maintain stable for 600 seconds with +0.1V bias on the top electrode. Using the Al/NiO/Pt structure, the IRESET, VSET and on/off ratio of RRAM devices with 128nm NiO are higher than those with 53nm NiO. The I-V conduction mechanism of on-state is ohmic, and that of off-state is thermionic emission. In Al/Ni-NiO-Ni/Pt structure, the conduction mechanism of on-state of is deviated from ohmic behavior but approaches to the space-charged-limited-current behavior. After annealing, the conduction mechanism of on-state again becomes ohmic. The conduction mechanisms of off-state of samples with and without annealing both follow thermionic emission principle.

    摘要 I Abstract III 誌謝 V 總目錄 VI 表目錄 IX 圖目錄 X 第1章 緒論 1 1-1 前言 1 1-2 研究目的與動機 3 第2章 理論基礎 4 2-1 次世代非揮發性記憶體 4 2-1-1 鐵電記憶體（FeRAM） 4 2-1-2 磁阻記憶體（MRAM） 5 2-1-3 相變化記憶體（PRAM） 6 2-1-4 電阻式記憶體（RRAM） 6 2-2 電阻式記憶體 11 2-2-1 鋯酸鍶（SrZrO3） 11 2-2-2 鐠鈣錳氧（Pr0.7Ca0.3MnO3, PCMO） 13 2-2-3 二氧化鈦（TiO2） 13 2-3 氧化鎳基本特性介紹 21 2-4 氧化鎳電阻式記憶體相關文獻回顧 26 2-5 介電層導電機制 33 2-5-1 穿隧（Tunneling） 33 2-5-2 熱發射（Thermionic emission）或蕭基發射（Schottky emission） 34 2-5-3 法蘭克－普爾發射（Frenkek-Poole emission） 36 2-5-4 歐姆效應（Ohmic） 37 2-5-5 離子電導（Ionic conduction） 37 2-5-6 空間電荷限制電流（space charge limited current, SCLC） 38 第3章 實驗方法與步驟 41 3-1 實驗材料 41 3-1-1 濺鍍靶材（sputtering target） 41 3-1-2 基材（Substrate） 42 3-1-3 製備薄膜所需氣體 42 3-1-4 實驗相關化學藥品與耗材 43 3-2 實驗設備 44 3-2-1 濺鍍系統 44 3-2-2 乾式熱氧化系統 46 3-2-3 氣氛退火系統 47 3-3 實驗流程 48 3-3-1 基材清洗 48 3-3-2 基本材料特性分析之氧化鎳薄膜的製備 49 3-3-3 電性量測之Al/NiO/Pt結構RRAM元件之製備 49 3-3-4 電性量測之Al/Ni-NiO-Ni/Pt結構RRAM元件之製備 51 3-3-5 退火處理 52 3-3-6 霍爾量測試片製備 52 3-4 分析儀器 58 3-4-1 表面粗度儀（Alpha-step） 58 3-4-2 穿透式電子顯微鏡（Transmission Electron Microscope, TEM） 58 3-4-3 電子微探儀（Electron Probe X-ray Microanalyzer, EPMA） 59 3-4-4 低掠角Ｘ光繞射分析儀（Glancing Incident Angle XRD, GIAXRD） 59 3-4-5 四點探針（4-point probe） 60 3-4-6 霍爾效應量測系統（Hall effect measurement） 61 3-4-7 精密半導體參數分析儀（Precision Semiconductor Parameter Analyzer） 61 第4章 結果與討論 63 4-1 試片編號命名法 63 4-2 氧化鎳層材料分析 66 4-2-1 厚度量測 66 4-2-2 氧化鎳薄膜成份分析 69 4-2-3 氧化鎳薄膜結晶結構分析 71 4-2-4 氧化鎳薄膜導電性質量測－四點探針電阻率量測 73 4-2-5 氧化鎳薄膜導電性質量測－霍爾效應分析 75 4-3 RRAM元件之電性量測分析 77 4-3-1 Al/NiO/Pt之電阻轉換性質量測 77 4-3-2 Al/Ni-NiO-Ni/Pt之電阻轉換性質量測 85 4-3-3 介電層導電機制之分析 94 4-4 電阻轉換機制之探討 109 第5章 結論 113 第6章 參考文獻 115

    1. 李修瑩， “韓國次世代非揮發性記憶體發展現況與策略”，拓墣產業研究所，(2007)。
    2. 高士， “非揮發性記憶體明日之星-快閃IC「RRAM」發展動向”，零組件雜誌，167，78-88，(2005)。
    3. 簡昭欣、呂正傑、陳志遠、張茂男、許世祿、趙天生， “先進記憶體簡介”，國研科技，1，31-36，(2004)。
    4. A. Beck, J. G. Bednorz, Ch. Gerber, C. Rossel, and D. Widmer, “Reproducible switching effect in thin oxide films for memory applications”, Applied Physics Letters, Vol. 77, No. 1, pp. 139-141, (2000).
    5. C. Rossel, G. I. Meijer, D. Bre´maud, and D. Widmer, “Electrical current distribution across a metal–insulator–metal structure during bistable switching”, Journal of Applied Physics, Vol. 90, No. 6, pp. 2892-2898, (2001).
    6. Chun-Chieh Lin, Bing-Chung Tu, Chao-Cheng Lin, Chen-Hsi Lin, “Resistive Switching Mechanisms of V-Doped SrZrO3 Memory Films”, IEEE Electron Device Letters, Vol. 27, No. 9, pp. 725-727, (2006).
    7. Jae-Wan Park, Kyooho Jung, Min Kyu Yang, Jeon-Kook Lee, Dal-Young Kim, and Jong-Wan Park, “Resistive switching characteristics and set-voltage dependence of low-resistance state in sputter-deposited SrZrO3:Cr memory films”, Journal of Applied Physics, 99, 124102, (2006).
    8. Chih-Yi Liu, Chun-Chieh Chuang, Jian-Shian Chen, Arthur Wang, Wen-Yueh Jang, Jien-Chen Young, Kuang-Yi Chiu, and Tseung-Yuen Tseng, “Memory effect of sol–gel derived V-doped SrZrO3 thin films”, Thin Solid Films, Vol. 494, pp. 287-290, (2006).
    9. R. Oligschlaeger, R. Waser, R. Meyer, S. Karthäuser, and R. Dittmann, “Resistive switching and data reliability of epitaxial (Ba,Sr)TiO3 thin films”, Applied Physics Letters, 88, 042901, (2006).
    10.S. Tsui, A. Baikalov, J. Cmaidalka, Y. Y. Sun, Y. Q. Wang, Y. Y. Xue, C. W. Chu, L. Chen and A. J. Jacobson, “Field-induced resistive switching in metal-oxide interfaces”, Applied Physics Letters, Vol. 85, No. 2, pp. 317-319, (2004).
    11.Akihiro Odagawa, Tsutomu Kanno, and Hideaki Adachi, “Transient response during resistance switching in Ag/Pr0.7Ca0.3MnO3/Pt thin films”, Journal of Applied Physics, 99, 016101, (2006).
    12.Dooho Choi, Dongsoo Lee, Hyunjun Sim, Man Chang, and Hyunsang Hwang, “Reversible resistive switching of SrTiOx thin films for nonvolatile memory applications”, Applied Physics Letters, 88, 082904, (2006).
    13.Markus Janousch, G. Ingmar Meijer, Urs Staub, Bernard Delley, Siegfried F. Karg, and Björn P. Andreasson, “Role of Oxygen Vacancies in Cr-Doped SrTiO3 for Resistance-Change Memory”, Advanced Materials, Vol. 0000, No. 00, pp. 1-5, (2007).
    14.B. J. Choi, D. S. Jeong, S. K. Kim, C. Rohde, S. Choi, J. H. Oh, H. J. Kim, C. S. Hwang, K. Szot, R. Waser, B. Reichenberg, and S. Tiedke, “Resistive switching mechanism of TiO2 thin films grown by atomic-layer deposition”, Journal of Applied Physics, 98, 033715, (2005).
    15.Christina Rohde, Byung Joon Choi, Doo Seok Jeong, Seol Choi, Jin-Shi Zhao, and Cheol Seong Hwang, “Identification of a determining parameter for resistive switching of TiO2 thin films”, Applied Physics Letters, 86, 262907, (2005).
    16.Byung Joon Choi, Seol Choi, Kyung Min Kim, Yong Cheol Shin, Cheol Seong Hwang, Sung-Yeon Hwang, Sung-sil Cho, Sanghyun Park, and Suk-Kyoung Hong, “Study on the resistive switching time of TiO2 thin films”, Applied Physics Letters, 89, 012906, (2006).
    17.Kyung Min Kim, Byung Joon Choi, Doo Seok Jeong, Cheol Seong Hwang, and Seungwu Han, “Influence of carrier injection on resistive switching of TiO2 thin films with Pt electrodes”, Applied Physics Letters, 89, 162912, (2006).
    18.Kyung Min Kim, Byung Joon Choi, Bon Wook Koo, Seol Choi, Doo Seok Jeong, and Cheol Seong Hwang, “Resistive Switching in Pt/Al2O3/TiO2/Ru Stacked Structures”, Electrochemical and Solid-State Letters, Vol. 9, No. 12, pp. G343-G346, (2006).
    19.Masayuki FUJIMOTO, Hiroshi KOYAMA, Yasunari HOSOI, Kazuya ISHIHARA, and Shinji KOBAYASHI, “High-Speed Resistive Switching of TiO2/TiN Nano-Crystalline Thin Film”, Japanese Journal of Applied Physics, Vol. 45, No. 11, pp. L310-L312, (2006).
    20.Doo Seok Jeong, Herbert Schroeder, and Rainer Waser, “Impedance spectroscopy of TiO2 thin films showing resistive switching”, Applied Physics Letters, 89, 082909, (2006).
    21.Doo Seok Jeong, Herbert Schroeder, and Rainer Waser, “Coexistence of Bipolar and Unipolar Resistive Switching Behaviors in a Pt/TiO2/Pt Stack”, Electrochemical and Solid-State Letters, Vol. 10, No. 8, pp. G51-G53, (2007).
    22.Herbert Schroeder, and Doo Seok Jeong, “Resistive switching in a Pt/TiO2/Pt thin film stack- a candidate for a non-volatile ReRAM”, Microelectronic Engineering, Vol. 84, pp. 1982-1985, (2007).
    23.S. Seo, M. J. Lee, D. H. Seo, E. J. Jeoung, D.-S. Suh, Y. S. Joung, I. K. Yoo, I. R. Hwang, S. H. Kim, I. S. Byun, J.-S. Kim, J. S. Choi, and B. H. Park, “Reproducible resistance switching in polycrystalline NiO films”, Applied Physics Letters, Vol. 85, No. 23, pp. 5655-5657, (2004).
    24.Ming-Daou Lee, Chia-Hua Ho, Chi-Kuen Lo, Tai-Yen Peng, and Yeong-Der Yao, “Effect of Oxygen Concentration on Characteristics of NiOx-Based Resistance Random Access Memory”, IEEE Transactions On Magnetics, Vol. 43, No. 2, pp. 939-942, (2007).
    25.Yil-Hwan You, Byung-Soo So, Jin-Ha Hwang, Wontae Cho, Sun Sook Lee, Taek-Mo Chung, Chang Gyoun Kim, and Ki-Seok An, “Impedance spectroscopy characterization of resistance switching NiO thin films prepared through atomic layer deposition”, Applied Physics Letters 89, 222105, (2006).
    26.K. Kinoshita, T. Tamura, M. Aoki, Y. Sugiyama, and H. Tanaka, “Bias polarity dependent data retention of resistive random access memory consisting of binary transition metal oxide”, Applied Physics Letters, 89, 103509, (2006).
    27.Jae-Wan Park, Jong-Wan Park, Dal-Young Kim, and Jeon-Kook Lee, “Reproducible resistive switching in nonstoichiometric nickel oxide films grown by rf reactive sputtering for resistive random access memory applications”, J. Vac. Sci. Technol. A, Vol. 23, No. 5, pp. 1309-1313, (2005).
    28.S. Seo, M. J. Lee, D. H. Seo, S. K. Choi, D.-S. Suh, Y. S. Joung, I. K. Yoo, I. S. Byun, I. R. Hwang, S. H. Kim, and B. H. Park, “Conductivity switching characteristics and reset currents in NiO films”, Applied Physics Letters, 86, 093509, (2005).
    29.D. C. Kim, M. J. Lee, S. E. Ahn, S. Seo, J. C. Park, I. K. Yoo, I. G. Baek, H. J. Kim, E. K. Yim, J. E. Lee, S. O. Park, H. S. Kim, U-In Chung, J. T. Moon, and B. I. Ryu, “Improvement of resistive memory switching in NiO using IrO2”, Applied Physics Letters, 88, 232106, (2006).
    30.Dong-Wook KIM, Bae Ho PARK, Ranju JUNG, and Sunae SEO, “Reversible Resistance Switching Behaviors of Pt/NiO/Pt Structures”, Japanese Journal of Applied Physics, Vol. 46, No. 8A, pp. 5205-5207, (2007).
    31.M.D. Leea, C.K. Lo, T.Y. Peng, S.Y. Chen, Y.D. Yao, “Endurance study of switching characteristics in NiO films”, Journal of Magnetism and Magnetic Materials, Vol. 310, pp. e1030-e1031, (2007).
    32.D. C. Kim, S. Seo, S. E. Ahn, D.-S. Suh, M. J. Lee, B.-H. Park, I. K. Yoo, I. G. Baek, H.-J. Kim, E. K. Yim, J. E. Lee, S. O. Park, H. S. Kim, U-In Chung, J. T. Moon, and B. I. Ryu, “Electrical observations of filamentary conductions for the resistive memory switching in NiO films”, Applied Physics Letters, 88, 202102, (2006).
    33.S. Seo, M. J. Lee, D. C. Kim, S. E. Ahn, B.-H Park, Y. S. Kim, I. K. Yoo, I. S. Byun, I. R. Hwang, S. H. Kim, J.-S. Kim, J. S. Choi, J. H. Lee, S. H. Jeon, S. H. Hong, and B. H. Park, “Electrode dependence of resistance switching in polycrystalline NiO films”, Applied Physics Letters, 87, 263507, (2005).
    34.Min Gyu KIM, Sun Man KIM, Eun Jip CHOI, Seung Eon MOON, Jonghyurk PARK, Hyoung Chan KIM, Bae Ho PARK, Myoung Jae LEE, Sunae SEO, David H. SEO, Seung Eun AHN, and In Kyeong YOO, “Study of Transport and Dielectric of Resistive Memory States in NiO Thin Film”, Japanese Journal of Applied Physics, Vol. 44, No. 42, pp. L1301-L1303, (2005).
    35.Myoung-Jae Lee, Sunae Seo, Dong-Chirl Kim, Seung-Eon Ahn, David H. Seo, In-Kyeong Yoo, In-Gyu Baek, Dong-Sik Kim, Ik-Su Byun, Soo-Hong Kim, In-Rok Hwang, Jin-Soo Kim, Sang-Ho Jeon, and Bae Ho Park, “A Low-Temperature-Grown Oxide Diode as a New Switch Element for High-Density, Nonvolatile Memories”, Advanced Materials, Vol. 19, pp. 73-76, (2007).
    36.K.-C. Min, M. Kim, Y.-H. You, S.S. Lee, Y.K. Lee, T.-M. Chung, C.G. Kim, J.-H. Hwang, K.-S. An, N.-S. Lee, and Y. Kim, “NiO thin films by MOCVD of Ni(dmamb)2 and their resistance switching phenomena”, Surface & Coatings Technology, Vol. 201, pp. 9252-9255, (2007).
    37.Chih-Yang Lin, Chen-Yu Wu, Chung-Yi Wu, Tzyh-Cheang Lee, Fu-Liang Yang, Chenming Hu, and Tseung-Yuen Tseng, “Effect of Top Electrode Material on Resistive Switching Properties of ZrO2 Film Memory Devices”, IEEE Electron Device Letters, Vol. 28, No. 5, pp.366-368, (2007).
    38.X. Wu, P. Zhou, J. Li, L. Y. Chen, H. B. Lv, Y. Y. Lin, and T. A. Tang, “Reproducible unipolar resistance switching in stoichiometric ZrO2 films”, Applied Physics Letters, 90, 183507, (2007).
    39.Seunghyup Lee, Wan-Gee Kim, Shi-Woo Rhee, and Kijung Yong, “Resistance Switching Behaviors of Hafnium Oxide Films Grown by MOCVD for Nonvolatile Memory Applications”, Journal of The Electrochemical Society, Vol. 155, No. 2, pp. H92-H96, (2008).
    40.H. B. Lv, M. Yin, X. F. Fu, Y. L. Song, L. Tang, P. Zhou, C. H. Zhao, T. A. Tang, B. A. Chen, and Y. Y. Lin, “Resistive Memory Switching of CuxO Films for a Nonvolatile Memory Application”, IEEE Electron Device Letters, Vol. 29, No. 4, pp.309-311, (2008).
    41.N. Ohshima, M. Nakada, Y. Tsukamoto, “Structural and magnetic properties of Ni-O/Ni-Fe bilayer films”, Japanese Journal of Applied Physics, Vol. 35, pp. L1585-L1588, (1996).
    42.O. Kohmoto, H. Nakagawa, F. Ono, A. Chayahara, “Ni-defective value and resistivity of sputtered NiO films”, Journal of Magnetism and Magnetic Materials, Vol. 226-230, pp. 1627-1628, (2001).
    43.Y. M. Chiang, D. P. Birnie III, W. D. Kingery, “Physical ceramics”, John Wiley & Sons, p. 24, p. 105, p. 129, p. 131, (1997).
    44.B. D. Cullity, S. R. Stock, “Elements of X-ray diffraction”, 3rd edition, Prentice Hall, p. 48, (2001).
    45.I. Hotový, D Búc, Š. Haščίk, and O. Nennewitz, “Characterization of NiO thin films deposited by reactive sputtering”, Vacuum, Vol.50, No. 1-2, pp. 41-44, (1998).
    46.T. B. Massalski, J. L. Murray, L. H. Bennett, H. Baker, “Binary alloy phase diagrams”, American Society for Metals, p. 1737, (1987).
    47.O. Kohmoto, H. Nakagawa, Y. Isagawa, and A. Chayahara, “Effect of heat treatment on the oxygen content and resistivity in sputtered NiO films”, Journal of Magnetism and Magnetic Materials, Vol. 226-230, pp. 1629-1630, (2001).
    48.David Adler, and Julius Feinleib, “Electrical and Optical Properties of Narrow-Band Materials”, Physical Review B, Vol. 2, No. 8, pp. 3112-3134, (1970).
    49.I.G. Baek, M.S. Lee, S. Seo, M.J. Lee, D.H. Seo, D.S. Suh, J.C. Park, S.O. Park, H. S. Kim, I.K. Yoo, U.I. Chung, and J.T. Moon, “Highly Scalable Non-volatile Resistive Memory using Simple Binary Oxide Driven by Asymmetric Unipolar Voltage Pulses”, IEDM Tech. Dig., (2004).
    50.S. M. Sze, Kwok K. Ng, “Physics of Semiconductor Devices”, 3rd edition, Wiley-interscience, p. 227, p. 228, (2007).
    51. Isao H. Inoue, M. J. Rozenberg, S. Yasuda, M. J. Sánchez, M. Yamazaki, T. Manago, H. Akinaga, H. Takagi, H. Akoh, and Y. Tokura, “Strong electron correlation effects in non-volatile electronic memory devices”, IEEE. Non-Volatile Memory Technology Symposium, pp. 131-136, (2005).

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