非揮發性電阻式記憶體因具備操作電壓低、操作速度快、耐久性佳、記憶元件面積小、及結構簡單化等優點，在目前的研究中備受矚目。近期以過渡金屬的二元氧化物為材料的這方面研究中，如氧化鋅和二氧化鉿等，已得到相當不錯的成果，然而要實際應用於記憶體的開發上，需要對電阻轉換機制更深入瞭解。
本實驗成功以原子層化學氣相沉積法於TiN/Ti/SiO2/Si基板上鍍製HfO2薄膜，再鍍製Pt上電極形成金屬/電阻層/金屬(MIM)結構的電阻式記憶體元件。進一步針對Pt/HfO2/TiN結構，嘗試於上或下電極介面加入TiO2薄膜，形成HfO2‐TiO2的疊層薄膜結構，在所設計的Type 1 : Pt/HfO2/TiN、Type 2 : Pt/HfO2/TiO2/TiN、Type 3 : Pt/TiO2/HfO2/TiN、Type 4 : Pt/TiO2/HfO2/TiO2/TiN等四種結構中，皆觀察到雙極性電阻轉換效應。利用材料分析、空間電荷限制電流理論分析、電極面積效應分析，並綜合電性量測的結果，嘗試探討TiO2薄膜於不同介面位置對電阻轉換的影響，試圖從中歸納出可能的電阻轉換機制。

第一章 緒論 1
第二章 文獻回顧 3
2.1 記憶體簡介 3
2.1.1 鐵電記憶體(FeRAM) 4
2.1.2 磁阻記憶體(MRAM) 4
2.1.3 相變化記憶體(PCRAM) 5
2.1.4 電阻式記憶體(RRAM) 5
2.1.4.1 過渡金屬氧化物型電阻式記憶體 6
2.3 電阻轉換機制簡介 8
2.4 漏電流傳導機制簡介 9
2.3.1 空間電荷限制電流 10
第三章 實驗流程 22
3.1 實驗動機 22
3.2 基板的製備 22
3.3 HfO2-TiO2薄膜的製備 22
3.4 Pt上電極的製備 23
3.5 薄膜分析與量測 23
3.5.1 薄膜結晶性分析 23
3.5.2 薄膜厚度及微結構分析 24
3.5.3 薄膜成份分析 24
3.5.4 電性分析 24
第四章 結果與討論 27
4.1 薄膜特性分析 27
4.1.1 薄膜結晶性分析 27
4.1.2 薄膜厚度及微結構分析 27
4.1.3 薄膜成份分析 28
4.2 薄膜電性分析 29
4.2.1基本IV特性 29
4.2.1.1 Type 1結構IV特性 29
4.2.2四種結構的電性比較 31
4.2.2.1 初始狀態比較 31
4.2.2.2 高低阻值分佈比較 32
4.2.2.3 操作電壓/電流比較 32
4.2.2.4 綜合比較 33
4.2.3 Type 1和Type 3的記憶時間測試比較 34
4.3 電阻轉換效應的探討 34
4.3.1空間電荷限制電流(SCLC)理論分析 34
4.3.2 改變電極面積對高低阻值的影響 35
4.3.3 電阻轉換效應的機制 37
4.3.3.1 由電阻轉換效應機制解釋電極面積效應 38
4.3.3.2 由電阻轉換效應機制解釋記憶時間測試結果 39
4.3.3.3 由電阻轉換效應機制解釋電性量測結果 40
第五章 結論 64
第六章 參考文獻 66

[1] H. Y. Lee, P. S. Chen, T. Y. Wu, Y. S. Chen, C. C. Wang, P. J. Tzeng, C. H. Lin,
F. Chen, C. H. Lien, and M.-J. Tsai, “Low power and high speed bipolar switching with a thin reactive Ti buffer layer in robust HfO2 based RRAM,” IEDM Tech. Dig., p.297, (2008)
[2] Gerhard Muller, Thomas Happ, Michael Kund, Gill Young Lee, Nicolas Nagel, and Recai Sezi, “Status and Outlook of Emerging Nonvolatile Memory Techologies,” IEEE, (2004)
[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,” 國研科技創刊號
[4] 劉志益、曾俊元, “電阻式非揮發記憶體之近期發展”
[5] http://www.pcmag.com/encyclopedia_term/0,2542,t=FeRAM&i=59446,00.asp
[6] 葉林秀、李佳謀、徐明豐、吳德和, “磁阻式隨機存取記憶體技術的發展
— 現在與未來,” 物理雙月刊(廿六卷四期) , (2004)
[7] 余昭倫, “綜觀新世代記憶體 ─ 相變化記憶 (PCRAM),” Digitimes 技術 IT, (2006)
[8] S.Q. Liu, N. J. Wu, and A. Ignatiev, “Electric-pulse-induced reversible resistance change effect in magnetoresistive films,” Appl. Phys. Lett. 76, 2749, (2000)
[9] 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, 4073, (2004)
[10] A. Beck, J. G. Bednorz, Ch. Gerber, C. Rossel and D. Widmer, “Reproducible switching effect in thin oxide films for memory applications,” Appl. Phys. Lett. 77, 139, (2000)
[11] C. Rossel, G. I. Meijer, D. Bre’maud, and D. Widmer, “Electrical current distribution across a metal-insulator-metal structure during bistable switching,” J. Appl. Phys. 90, 2892, (2001)
[12] Liping Ma, Jie Liu, Seungmoon Pyo, and Yang Yang, “Organic bistable light-emitting devices,” Appl. Phys. Lett. 80, 362, (2002)
[13] L. P. Ma, J, Liu and Y. Yang, “Organic electrical bistable devices and rewritable memory cells,” Appl. Phys. Lett. 80, 2997, (2002)
[14] 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.,p.587, (2004)
[15] 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,” Appl. Phys. Lett. 85, 5655, (2004)
[16] W. Y. Chang, Y. C. Lai, T. B. Wu, S. F. Wang, F. Chen, and M. J. Tsai, “Unipolar resistive switching characteristics of ZnO thin films for nonvolatile memory applications,” Appl. Phys. Lett. 92, 022110, (2008)
[17] K. M. Kim, B. J. Choi, Y. C. Shin, S. Choi, and C. S. Hwang, ”Anode-interface localized filamentary mechanism in resistive switching of TiO2 thin films,” Appl. Phys. Lett. 91, 012907, (2007)
[18] C. Y. Lin, C. Y. Wu, C. Y. Wu, T. Y. Tseng, and Chenming Hu, “Modified resistive switching behavior of ZrO2 memory films based on the interface layer formed by using Ti top electrode,” J. Appl. Phys. 102, 094101, (2007)
[19] C. Y. Lin, C. Y. Wu, C. Y. Wu, T. C. Lee, F. L. Yang, Chenming Hu, and T. Y. Tseng, “Effect of Top Electrode Material on Resistive Switching Properties of ZrO2 Film Memory Devices,” IEEE Electron Device lett. vol. 28, no. 5, p.366-368, (2007)
[20] Akihito Sawa, “Resistive switching in transition metal oxides,” materials today, 11, 28, (2008)
[21] Rainer Waser, and Masakazu Aono, “Nanoionics-based resistive switching memories,” Nat. Mater. 6, 833, (2007)
[22] 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,” Appl. Phys. Lett. 89, 103509, (2006)
[23] K. M. Kim, B. J. Choi, and C. S. Hwang, “Localized switching mechanism in resistive switching of atomic-layer-deposited TiO2 thin films,” Appl. Phys. Lett. 90, 242906, (2007)
[24] Krzysztof Szot, Wolfgang Speier, Gustav Bihlmayer, and Rainer Waser, “Switching the electrical resistance of individual dislocations in single- crystalline SrTiO3,” Nat. Mater. 5, 312, (2006)
[25] A. Baikalov, Y. Q. Wang, B. Shen, B. Lorenz, S. Tsui, Y. Y. Sun, Y. Y. Xue, and C. W. Chu, ” Field-driven hysteretic and reversible resistive switch at the Ag–Pr0.7Ca0.3MnO3 interface” Appl. Phys. Lett. 83, 957, (2003)
[26] 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,” Appl. Phys. Lett. 85, 317, (2004)
[27] X. Chen, N. J. Wu, J. Strozier, and A. Ignatiev, “Direct resistance profile for an electrical pulse induced resistance change device,” Appl. Phys. Lett. 87, 233506, (2005)
[28] A. Sawa, T. Fujii, M. Kawasaki, and Y. Tokurad, “Hysteretic current–voltage characteristics and resistance switching at a rectifying Ti/Pr0.7Ca0.3MnO3 interface,” Appl. Phys. Lett. 85, 4073, (2004)
[29] T. Fujii, M. Kawasaki, A. Sawa, H. Akoh, Y. Kawazoe, and Y. Tokura, “Hysteretic current–voltage characteristics and resistance switching at an epitaxial oxide Schottky junction SrRuO3 /SrTi0.99Nb0.01O3,” Appl. Phys. Lett. 86, 012107, (2005)
[30] Rickard Fors, Sergey I. Khartsev, and Alexander M. Grishin, “Giant resistance switching in metal-insulator-manganite junctions: Evidence for Mott transition,” Phys. Rev. B, 71, 045305, (2005)
[31] M. J. Rozenberg, I. H. Inoue, and M. J. Sánchez, “Strong electron correlation effects in nonvolatile electronic memory devices,” Appl. Phys. Lett. 88, 033510, (2006)
[32] Hyunjun Sim, Hyejung Choi, Dongsoo Lee, Man Chang, Dooho Choi, Yunik Son, Eun-Hong Lee, Wonjoo Kim, Yoondong Park, In-Kyeong Yoo, and Hyunsang Hwang, “Excellent Resistance Switching Characteristics of Pt/SrTiO3 Schottky Junction for Multi-bit Nonvolatile Memory Application,” IEDM Tech. Dig., p.758, (2005)
[33] 王琮鴻, “金屬/ 氧化鋯/ 半導體電容器與場效電晶體之製作與電性分析,” 清華大學碩士論文, (2004)
[34] T. Hori, Gate dielectrics and MOS ULSIs：principle, technologies, and applications, Springer, Berlin, p.8, 45, (1997)
[35] F. C. Chiu, “Electrical characterization and current transportation in metal/Dy2O3/Si structure,” J. Appl. Phys. 102, 044116, (2007)
[36] Nuo Xu, Lifeng Liu, Xiao Sun, Xiaoyan Liu, Dedong Han, Yi Wang, Ruqi Han, Jinfeng Kang, and Bin Yu, “Characteristics and mechanism of conduction/set process in TiN/ZnO/Pt resistance switching random-access memories,” Appl. Phys. Lett. 92, 232112, (2008)
[37] P. T. Hsieh, Y. C. Chen, K. S. Kao, and C. M. Wang, “Luminescence mechanism of ZnO thin film investigated by XPS measurement,” Appl. Phys. A 90, p.317, (2008)