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研究生:謝嘉榮
研究生(外文):Chia-JungHsieh
論文名稱:利用聚焦離子束製作具侷限導通區域之氧化鈦電阻式記憶體
論文名稱(外文):Confined Resistive Switching in a Focus Ion Beam recessed nanopore of TiO2 Dielectrics Resistive Random Access Memory
指導教授:王水進
指導教授(外文):Shui-Jinn Wang
學位類別:碩士
校院名稱:國立成功大學
系所名稱:電機工程學系專班
學門:工程學門
學類:電資工程學類
論文種類:學術論文
論文出版年:2012
畢業學年度:100
語文別:中文
論文頁數:66
中文關鍵詞:氧化鈦侷限導通電阻式記憶體
外文關鍵詞:RRAMFIBNanopore
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本篇論文之主要架構是探討利用聚焦離子束機台(focus ion beam, FIB)於高介電材料二氧化鈦層進行局部蝕刻,以獲得直徑為20~40 nm深度約為20 nm之奈米孔洞(nanopores),再以dual beam FIB所擁有之CVD功能,利用其較佳之階梯覆蓋能力直接沉積上電極(Pt)之方式製作電阻式記憶體試片,期望能侷限電阻式記憶體之導通路徑於奈米尺寸範圍,進而觀察電阻式記憶體之導通行為。亦希望藉由侷限導通方式去改善電阻式記憶體的電性均勻度以及降低電致(forming)電壓與寫入訊號(set)電壓與拭除訊號(reset)電壓之準位(voltage),達到降低消耗功率及提昇穩定度的效果。
本篇論文以聚焦離子束(FIB)減少高介電金屬氧化層局部厚度而使得此電阻式記憶體之導通路徑有效被侷限在特定區域,再透過電性量測方式,以確認其主要導通機制以及擁有均勻電性結果之原因。我們亦嘗試進一步藉由Conductive AFM 方式去驗證導通路徑是否如預期被侷限在靠近FIB局部蝕刻的區域,以便與電性結果相呼應。
據厚度75 nm二氧化鈦試片之電性實驗量測數據顯示,未經蝕刻的試片與經過局部蝕刻(孔洞深度與面積分別為20 nm與314.1 nm2)的試片,其寫入訊號(set)電壓與拭除訊號(reset)電壓之準位(voltage)分別為-3.8 V/3.1 V與-1.5 V/1.8 V,呈現明顯差異。另一個經TEM確認孔洞深度約40 nm之試片,其操作電壓亦下降至-1.1 V/1.4 V。透過上述電性實驗量測資料分析,我們得以確認這些試片的導通行為因FIB的局部加工而有明顯的變化,即使與另一組原始厚度為50 nm且無奈米孔洞之試片比較(操作電壓為-3.4 V/2.2 V),經FIB局部蝕刻的試片(原始厚度75 nm,蝕刻深度20 nm,局部厚度接近50 nm)依然有明顯較低的操作電壓-1.5 V/1.8 V,與預期之侷限導通的結果相符。針對試片導通電流分布情況,本研究亦使用C-AFM進行進一步分析。於前後兩次導通之on-off-on current map中,可見到其元件於奈米孔洞導通之位置是一致的,此結果符合我們所預期之侷限導通現象。
The present thesis is devoted to the study of the conduction behavior of a resistive random access memory (RRAM) confined within a nanometer-sized pore (nanopore) recessed by focus ion beam (FIB). TiO2 high-k dielectric which is one of the most popular transition metal oxide[1]is employed in this study. Nanopores with diameter ranging from 20 to 40 nm and depth 20 nm were recessed on the TiO2 film and refilled with Pt (~1 m in thickness) top electrode using a CVD system equipped with the FIB system. A better step coverage is obtained from the process design.

The proposed device structure is expected to reduce both the set and reset voltage compared to conventional flate RRAM without nanopores and to reduce power consumption. With current conduction confined with the nanopore, the prepared RRAMs have comparatively lower forming/set/reset voltage than those of without nanopores on the dielectric layer. The current conduction behavior of the RRAM with nanopore is investigated. Conductive atomic focus microscopy (C-AFM) was used to monitor the locations of conduction spots during the switching of devices.

Based on the electrical I-V curves measurement data, the samples with and without nanopores show very different set and reset voltages at -3.8 V/3.1 V and -1.5 V/1.8 V, respectively. Significant operation voltage difference caused by the nanopores is observed. Samples with 75-nm-thick TiO2 film and 40-nm-deep nanopore (verified by TEM) showing set and reset voltage lower down to -1.1 V/1.4 V are also demonstrated. As compared to the one with 50-nm-thick TiO2 film but without nanopore, which has set/reset voltage of -3.4 V/2.2 V, the sample with nanopore (thickness 75 nm, nanopore depth 20nm) has a lower operation voltage (-1.5 V/1.8 V) as expected. Accodding to C-AFM analysis, the current mapping obtained from twice switching process (with the sequence on-off-on) confirms that the conduction path during switching is confined within the same location within the nanopore. It is expected that the introduction of FIB recessed nanopore on the high-k dielectric of RRRM have potential in clarifying the related transport mechanism and improving devcie performance.

目錄

中文摘要 I
英文摘要 III
誌 謝 V
目 錄 VII
表 目 錄 X
圖 目 錄 XI
第一章、緒論 1
1-1、前言 1
1-1-1、記憶體簡介 2
1-1-2、電阻式記憶體簡介 3
1-2、研究現況與動機 7
1-2-1、研究現況 7
1-2-2、研究動機 9
第二章、RRAM理論基礎與機制 14
2-1、電阻式記憶體的材料特性介紹 14
2-1-1、TiO2電阻式記憶體相關文獻回顧 14
2-1-2、二氧化鈦(Titanium dioxide)材料基本特性介紹 15
2-1-3、電極材料介紹 19
2-2、薄膜導通理論基礎與RRAM機制介紹 19
2-2-1、基本薄膜傳導機制介紹 (Condunction Mechanism) 19
2-2-2、RRAM 轉換機制 23
2-2-3、RRAM 之電致步驟及量測方式 28
第三章、實驗設備、流程及分析方法 31
3-1、實驗儀器設備 31
3-1-1、聚焦離子槍 (Focus Ion Beam,縮寫FIB) 31
3-1-2、射頻磁控濺鍍機 33
3-1-3、電子束蒸鍍機 33
3-2、薄膜結構分析儀器 34
3-2-1、光繞射分析(XRD) 34
3-2-2、掃描式電子顯微鏡 36
3-2-3、穿透式電子顯微鏡 38
3-2-4、導電式原子力顯微鏡(CAFM) 39
3-3、量測儀器 41
3-3-1、參數分析儀 41
3-3-2、Probe Station 41
第四章、運用FIB局部蝕刻及電極沉積之TiO2電阻式記憶體. 43
4-1、實驗流程與步驟 43
4-2、FIB Recessed TiO2電阻式記憶體製作流程圖 45
4-3、FIB Recessed TiO2電阻式記憶體之基本電性量測結果 47
4-3-1、電壓-電流之電致曲線 (I-V Curves of Forming) 47
4-3-2、Set與Reset電流-電壓曲線 48
4-3-3、高阻值與低阻值比 50
4-4、基本電性量測結果之探討 51
第五章、元件物理結構分析及導通機制探討 53
5-1、FIB Recess TiO2電阻式記憶體之TEM橫截面 53
5-2、TiO2局部厚度不同的實驗組別之I-V Curves特性討論 55
5-3、C-AFM偵測分析與結果探討 57
第六章、結論 59
6-1、結論 59
6-2、研究之建議與Future Works 62
參考文獻 63

參考文獻

[1]Yoshinori Tokura, “Correlated-Electron Physics in Transition-Metal Oxide,Physical today, pp. 50-54, 2003.
[2]Wade Xiong, “RRAM Materials Development at SEMATECH, SE-MATECH Symposium Taiwan, pp. 17-18, 2010.
[3]H. Sim, D.J.Seong, M. Chang, Excellent Resistance Switching Characteristics of Pt/Single-crystal Nb-Doped SrTiO3, IEEE, pp. 1-4, 2006.
[4]B. P. Andreasson, M. Janousch, U. Staub et al., Resistive switching in Cr-doped SrTiO3: An X-ray absorption spectroscopy study, Materials Science and Engineering B-Solid State Materials for Advanced Technology, IEEE Electron Device Letters, vol. 32, no. 3, pp. 1-3, 2011.
[5]R. Oligschlaeger, R. Waser, R. Meyer et al., Resistive switching and data reliability of epitaxial (Ba,Sr)TiO3 thin films, Applied Physics Letters 88, pp. 1-3, 2006.
[6]C.Y. Liu, C.C. Chuang, J.S. Chen et al., Memory effect of sol-gel de-rived V-doped SrZrO3 thin films, pp. 3-4, 2006.
[7]D. Hsu, J. G. Lin, and W. F. Wu, Resistive switch in effects in Nd0.7Ca0.3MnO3 manganite, Journal of Magnetism and Magnetic Materials, pp. 1-3, 2007.
[8]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, B. H. Park, “Reproducible Resistance Switching in polycrystalline NiO Films , Appl. Phys. Lett., vol. 85, no. 23, pp. 5655–5657, 2004.
[9]S. Zhang, S. B. Long, W. H. Guan, Q. Liu, Q. Wang, M. Liu, “Resistance switching of Au-implanted-ZrO2 film for nonvolatile memory application, J. Appl. Phys., pp. 1-3, 2009.
[10]W. Wang, S. Fujita, and S.S. Wong, “Elimination of forming process forTiOx nonvolatile memory devices, IEEE Electron Device Lett., vol. 30, no. 7, pp. 763–765, 2009.
[11]Rainer Waser and Masakazu Aono, ‘‘Nanoionics-based resistive switching memories., Nature materials, Vol. 6, pp. 833-840, 2007.
[12]Z. Fang, H. Y. Yu, X. Li, N. Singh, G.Q. Lo, and D. L. Kwong, “Multilayer-Based Forming-Free RRAM Devices With Excellent Uniformity, IEEE Electron Device Letters, Vol. 32, no. 4, pp. 566 –568, 2011.
[13]P.D. Kirsch and the Memory Team “SEMATECH 2011, Progress on RRAM as a future Non-Volatine Memory (NVM), pp. 3-4, 2011.

[14]David Gilmer, Hokyung Park, Chanro Park,Yongho Ha, Chang-Yong Kang, Melvin Cruz, Pat Lysaght, Dmitry Veksler, Gennadi Bersuker, Bill Taylor, Paul Kirsch, Raj Jammy “SEMATECH 2010, Progress in Metal Oxide RRAM p. 4, 2010.
[15]M.J. Rozenberg, I. H. Inoue, and M.J. Sanchez, “Nonvolatile memory with Multi-level Switching: A basic model, Journal of Semiconductor technology and science, vol.8, no.1, pp. 1-3, 2008
[16]Joe.james, data manual whitepaper SLC vs. MLC: An Analysis of FlashMemory, handbook, pp. 1-5, 2011.
[17]Jiwei Zhai and Haydn Chen, “Orientation Control and Dielectric Properties of Sol-gel Deposited (Ba,Sr)TiO3 Thin Films for Room-Temperature Tunable Element Applications, Journal of the Korean Ceramic Society, Vol. 40, No. 4, pp. 380-384, 2003.
[18]K Szot, M Rogala, WSpeier, Z Klusek, A Besmehn and R. Waser, “TiO2—a prototypical memristive material, Nanotechnology, pp. 1-6, 2011.
[19]R. Stanley Williams , “Emerging Non-Volatile Memory Technologies, 8th Annual Full Day Symposium presentation on IEEE Nanotechnology Concil , pp. 3-4, 2012.
[20]C. Nauenheim, C. Kuegeler, A. Ruediger, and R. Waser, “Investigation of the electroforming process in resistively switching TiO2 nanocross-point junctions, Applied Physics Letters, pp. 96-98, 2010.
[21]A. P. Alivisatos et al., J.Am “Chem. Soc, p. 122, 2000.
[22]T.C Wang, “Fabrication of TiO2 photoanode with compact layer and corallike nanowire integrated structure and its application on liquid electrolyte dye sensitized solar cell,vol. 2, p. 22-23, 2011.

[23]S.M. Sze (1999,8,10) basic book“Semiconductor Devices Physics and Technology3rd edition, John Wiley and Sons publish house, vol. 2, 1999,Available.
[24]S.J Wang,NCKU Melab,VLSI Introduction Course Materials, MS contacts, vol. 2-B, pp22-23, 2009.
[25]H. A. Fowler, J. E. Devaney, and J. G. Hagedorn, Growth model for filamentary streamers in an ambient field, IEEE Transactions on Dielectrics and Electrical Insulation, pp. 73-79, 2003.
[26]Ilia Valov, Rainer Waser, JohnR Jameson and Michael N Kozicki, “ Electrochemical metallization memories—fundamentals, applications, prospects, Nanotechnology, pp. 22-25, 2011.
[27]A. Sawa, T. Fujii, M. Kawasaki, Hysteretic current-voltage characteristics and resistance switching at a rectifying Ti/Pr0.7Ca0.3MnO3 interface, Applied Physics Letters 85, pp. 4073-4075, 2004.
[28]Byoungil Lee and H.-S. Philip W, “Fabrication and Characterization of Nanoscale NiO Resistance Change Memory (RRAM) Cells With Con-fined Conduction Paths, IEEE Transations on Eelectron Devices, vol. 58, no. 10, pp. 3270-3273, 2011.
[29]S. Q. Liu, N. J. Wu, and A. Ignatiev, “Electric-pulse-induced reversible resistance change effect in magnetoresistive films, Appl. Phys. Lett., vol. 76, no. 19, pp. 2749–2751, 2000.
[30]Melngalis.J, Critical Review: Focus ion beam technology and applications, Journal of Vacuum Science Technology, pp. 1374-1375, 1987.
[31]Lee, Ming-Kwei; Kuo, Kwei-Kuan, “Gas-assisted etiching of sapphire Using Focus Ion Beam, Japanese Journal of Applied Physics, Volume 45, No.4A, pp.2447-2450, 2006.
[32]P. Kuo, “2011 seminar of FA house in Hsin-Chu, Failure analsis tool introduction,,pp. 2-8, March 2011.
[33]D. Kajewski, R. Wrzalik, M. Wojtyniak , M. Pilch, J. Szade, K. Szot, Ch. Lenser, R. Dittmann & R. Waser, “Local conductivity of epitaxial Fe-doped SrTiO3 thin films, Phase Transitions, Vol. 84, No. 5, pp. 483–488, 2011.
[34]B.J Choi, D.S. Jeong, S.K Kim et al., “ Resistance Switching Mechansim of TiO2 thin films grown by atomic-layer deposition, Journal of Applied Physics 98, pp. 2-10, 2005

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