人腦不同於現代電腦儲存記憶的方式，並非靠0和1的數位訊號來記憶，而是透過類比訊號來儲存記憶與傳遞訊息，本論文中製備鋰矽氧化物(LiSiOx)薄膜電阻式記憶體(RRAM)元件具有良好的多位元(multi-bit)儲存功能，並具有模擬神經元突觸的仿生特性，利用這種特性，仿效大腦學習的運作方式，未來有助於類神經網路的發展及大腦內類比訊號儲存與傳遞。
本論文以物理濺鍍方式沉積鋰矽氧化物薄膜，製作Pt/LiSiOx/TiN結構的鋰矽氧化物薄膜電阻式記憶體元件，藉由DC電流操作，可發現元件同時具有數位區及類比區的不同儲存方式，會出現具有兩段式劇烈的Reset行為，且Off State會大範圍的分布，使元件的讀取窗口在1~5個order分佈，並利用Current-Voltage Fitting提出之物理機制模型解釋，這部分研究成果已經發表在國際期刊。
透過不同電壓區間的掃描方式來觀測鋰離子在元件中所扮演的角色，元件可達到多位元儲存的功能，並利用陰陽離子移動使單層薄膜電阻式記憶體即可達到傳統互補式電阻開關(CRS)的功能，避免潛通道電流問題。
利用DC電流操作，使元件做連續性的Set跟Reset轉態行為，進一步以快速量測系統(Fast IV)驗證，證實元件具備類比訊號的資訊儲存功能，可在高低電阻態間連續性電阻值切換，透過模擬神經元中的突觸可塑性仿效神經元突觸的學習機制，顯現海伯學習法(Hebb's learning)中重要的尖峰時間依賴可塑性(STDP)及大腦記憶種類中的短期記憶(STM)、長期記憶(LTM)這些重要的仿生特性。
此外元件具有修復的功能，有別於一般電阻式記憶體會有阻絲形成過於完整造成元件無法在高低電阻態間切換的狀況，而此元件可透過定電壓方式修復，並可再次反覆操作，避免數位資訊的寫入抹除出現錯誤。

The information stored in human brain is different from computer, it storages and transmits messages through analog signal instead of digital signal. In this study, the lithium silicate resistive random access memory (RRAM) mimics synaptic-like biological behavior with multi-bit function. It is helpful for the development of artificial neural network and analog storage by emulating learning rules in the brain.
The lithium silicate thin film was prepared by RF sputtering, and it was fabricated the RRAM with Pt/LiSiOx/TiN structure. Though the electrical analysis, the lithium silicate RRAM shows abnormal resistive switching behaviors, especially the high resistance states distribute in a wide range. Based on the corroboration of conduction current fitting analysis, a model was proposed to explain the electrical resistive switching behaviors.
By controlling the stop-voltage, the device can achieve multi-bit function and perform complementary resistive switches (CRS). Generally, CRS consists of two anti-serial RRAMs to solve the sneak path problem. However, the lithium silicate RRAM can archive CRS in a single device due to the dual-ion effect (Li+ and O2-).
The lithium silicate RRAM device is demonstrated advanced synaptic function such as synaptic plasticity, a spike-timing-dependent plasticity (STDP), a short-term memory (STM) and long-term memory function (LTM), which is relying on the synaptic plasticity with a continuous transition between intermediate resistance states. Further, after a constant voltage applying, the irreversible switching from LRS to HRS is recovered, and the device reveals good endurance again.

致謝 i
中文摘要 ii
Abstract iii
目錄 iv
圖目錄 viii
表目錄 xii
第一章 緒論 1
1-1 前言 1
1-2 研究目的與動機 2
第二章 文獻回顧 3
2-1 次世代非揮發性記憶體 3
2-1-1 鐵電式記憶體(FeRAM) 3
2-1-2 磁阻式記憶體(MRAM) 4
2-1-3 相變化記憶體(PCRAM) 5
2-1-4 電阻式記憶體(RRAM) 6
2-2 電阻式記憶體切換機制 9
2-2-1 阻絲理論(Filament theory) 9
2-3 絕緣體載子傳導機制 10
2-3-1 歐姆傳導(Ohmic Conduction)[14] 11
2-3-2 蕭基發射(Schottky emission)[14] 12
2-3-3 普爾-法蘭克發射( Poole-Frenkel emission)[14] 13
2-3-4 跳躍傳導(Hopping Conduction)[14] 14
2-3-5 穿隧(Tunneling)[14] 15
2-4 互補式電阻切換(Complementary Resistive Switches，CRS) 16
2-5 神經系統構造 17
2-5-1 神經元(Neurons) 17
2-5-2 突觸(Synapse) 18
2-6 海伯學習法(Hebb's learning)[17] 18
2-7 尖峰時間依賴可塑性(Spike-Timing-Dependent Plasticity, STDP) 19
2-8 大腦的多位元儲存模型 20
2-9 巴甫洛夫的狗(Pavlov’s Dog) 21
第三章 實驗設備介紹 23
3-1 製程設備 23
3-1-1 多靶磁控濺鍍系統(Multi-Target Sputter)[23] 23
3-2 材料分析設備 24
3-2-1 傅立葉轉換紅外光譜儀(Fourier-Transform Infrared Spectrometer)[24] 24
3-2-2 X光電子能譜(XPS) 26
3-2-3 N&K薄膜特性分析儀(N & K analyzer) 27
3-3 電性量測設備 27
3-3-1 半導體精準電性量測系統 27
第四章 鋰矽氧化物薄膜電阻式記憶體(LiSiOx RRAM) 29
4-1 鋰矽氧化物薄膜電阻式記憶體製作流程 29
4-1-1 鋰矽氧化物薄膜備製 30
4-1-2 白金上電極備製 30
4-2 鋰矽氧化物薄膜材料分析 31
4-2-1 FTIR化學定性分析 31
4-2-2 XPS化學定量分析 32
4-3 鋰矽氧化物薄膜元件I-V特性 33
4-3-1 限制電流為1mA / 10mA下操作I-V特性比較 35
4-3-2 限制電流為10mA下連續操作 38
4-3-3 限制電流為10mA下操作不同Off State比較 40
4-3-4 模型建立 43
第五章 鋰矽氧化物薄膜電阻式記憶體於互補式電阻切換的應用 45
5-1 鋰離子效應 45
5-1-1 操作過程中的自限流(self-compliance current)現象 45
5-1-2 透過不同截止電壓操作多位元儲存(multi-bit storage) 47
5-2 雙離子型互補式電阻切換 49
5-2-1 雙離子型互補式電阻切換操作方式 49
5-2-2 傳統及雙離子型互補式電阻切換比較 50
第六章 鋰矽氧化物薄膜電阻式記憶體仿生特性 51
6-1 DC模式操作 51
6-1-1 固定截止電壓(Stop Voltage)連續操作 51
6-1-2 不同截止電壓(Stop Voltage) 53
6-2 Fast IV系統操作 55
6-2-1 連續Pulse Set、Pulse Reset操作 55
6-2-2 尖峰時間依賴可塑性(Spike-Timing-Dependent Plasticity, STDP) 57
6-2-3 學習效果曲線 60
6-3 記憶保存能力(Retention) 61
6-3-1 短時間升溫Retention測試 61
6-3-2 長時間常溫Retention測試 63
6-4 長時間常溫Retention結果分析 65
6-4-1 物理機制模型 65
第七章 鋰矽氧化物薄膜電阻式記憶體回復特性 68
7-1 不可回復性的操作造成判讀錯誤 68
7-1-1 元件回復特性 68
7-1-2 模型建立 69
第八章 鋰矽氧化物薄膜電阻式記憶體於電子皮膚上應用 74
8-1 鋰矽氧化物薄膜電阻式記憶體於電子皮膚製作流程 74
8-2 鋰矽氧化物薄膜電阻式記憶體於電子皮膚I-V特性 74
第九章 結論 76
參考文獻 77

[1] D. Kuzum, R. G. D. Jeyasingh, B. Lee, and H. S. P. Wong, "Nanoelectronic Programmable Synapses Based on Phase Change Materials for Brain-Inspired Computing," Nano Letters, vol. 12, pp. 2179-2186, May 2012.
[2] S. H. Jo, T. Chang, I. Ebong, B. B. Bhadviya, P. Mazumder, and W. Lu, "Nanoscale Memristor Device as Synapse in Neuromorphic Systems," Nano Letters, vol. 10, pp. 1297-1301, Apr 2010.
[3] M. N. Kozicki, C. Gopalan, M. Balakrishnan, and M. Mitkova, "A low-power nonvolatile switching element based on copper-tungsten oxide solid electrolyte," Ieee Transactions on Nanotechnology, vol. 5, pp. 535-544, Sep 2006.
[4] C. Schindler, S. P. Thermadam, R. Waser, and M. N. Kozicki, "Bipolar and Unipolar Resistive Switching in Cu-Doped SiO< sub> 2</sub>," Electron Devices, IEEE Transactions on, vol. 54, pp. 2762-2768, 2007.
[5] D. A. Buck, "Ferroelectrics for digital information storage and switching," MIT Digital Computer Laboratory1952.
[6] 鄭佩慈, "鐵電材料之特性與應用," 儀科中心簡訊, pp. 10-11, 2005.
[7] 葉林秀, 李佳謀, 徐明豐, and 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, vol. 26, pp. 607-619, 2004.
[8] 許峻銘, "氧化銅薄膜於非揮發電阻式記憶體特性之研究," 2009.
[9] K. Hsieh, "The Current progress of NVM," Macronix International Co, 2011.
[10] K. M. Kim, B. J. Choi, and C. S. Hwang, "Localized switching mechanism in resistive switching of atomic-layer-deposited TiO 2 thin films," Applied physics letters, vol. 90, pp. 242906-242906-3, 2007.
[11] A. Sawa, "Resistive switching in transition metal oxides," Materials today, vol. 11, pp. 28-36, 2008.
[12] J. Y. Chen, C. L. Hsin, C. W. Huang, C. H. Chiu, Y. T. Huang, S. J. Lin, et al., "Dynamic Evolution of Conducting Nanofilament in Resistive Switching Memories," Nano Letters, vol. 13, pp. 3671-3677, Aug 2013.
[13] H. S. P. Wong, H. Y. Lee, S. M. Yu, Y. S. Chen, Y. Wu, P. S. Chen, et al., "Metal-Oxide RRAM," Proceedings of the Ieee, vol. 100, pp. 1951-1970, Jun 2012.
[14] P. J. Kuekes, D. R. Stewart, and R. S. Williams, "The crossbar latch: Logic value storage, restoration, and inversion in crossbar circuits," Journal of Applied Physics, vol. 97, pp. -, 2005.
[15] E. Linn, R. Rosezin, C. Kügeler, and R. Waser, "Complementary resistive switches for passive nanocrossbar memories," Nature materials, vol. 9, pp. 403-406, 2010.
[16] S. I. Fox, Human physiology, 2008.
[17] D. O. Hebb, The organization of behavior: A neuropsychological theory: Psychology Press, 2005.
[18] G. Q. Bi and M. M. Poo, "Synaptic modifications in cultured hippocampal neurons: Dependence on spike timing, synaptic strength, and postsynaptic cell type," Journal of Neuroscience, vol. 18, pp. 10464-10472, Dec 1998.
[19] R. C. Atkinson and R. M. Shiffrin, "Human memory: A proposed system and its control processes," The psychology of learning and motivation, vol. 2, pp. 89-195, 1968.
[20] T. Ohno, T. Hasegawa, T. Tsuruoka, K. Terabe, J. K. Gimzewski, and M. Aono, "Short-term plasticity and long-term potentiation mimicked in single inorganic synapses," Nature Materials, vol. 10, pp. 591-595, Aug 2011.
[21] I. P. Pavlov, "Experimental psychology and psycho-pathology in animals," in International Congress of Medicine, Apr, 1903, Madrid, Spain, 1928.
[22] M. Ziegler, R. Soni, T. Patelczyk, M. Ignatov, T. Bartsch, P. Meuffels, et al., "An Electronic Version of Pavlov's Dog," Advanced Functional Materials, vol. 22, pp. 2744-2749, Jul 2012.
[23] H. Xiao, "Introduction to Semiconductor Manufacturing Technology," Prentice Hall, vol. 3rd Ed, 2007.
[24] Skoog, "Principles of Instrumental Analysis," Thomson Brooks, vol. Fifth Ed, pp. pp. 356-375, 2006.
[25] M. Q. Snyder, W. J. DeSisto, and C. P. Tripp, "An infrared study of the surface chemistry of lithium titanate spinel (Li4Ti5O12)," Applied Surface Science, vol. 253, pp. 9336-9341, Oct 15 2007.
[26] N. Yamamoto and H. Takai, "Visible luminescence from photo-chemically etched silicon," Thin Solid Films, vol. 359, pp. 184-187, Jan 2000.
[27] K.-C. Chang, C.-H. Pan, T.-C. Chang, T.-M. Tsai, R. Zhang, J.-C. Lou, et al., "Hopping effect of hydrogen-doped silicon oxide insert RRAM by supercritical CO2 fluid treatment," Ieee Electron Device Letters, 2013.
[28] T.-J. Chu, T.-M. Tsai, T.-C. Chang, K.-C. Chang, R. Zhang, K.-H. Chen, et al., "Tri-Resistive Switching Behavior of Hydrogen Induced Resistance Random Access Memory," Ieee Electron Device Letters, 2014.
[29] Y. Qiu, K. Yan, S. Yang, L. Jin, H. Deng, and W. Li, "Synthesis of Size-Tunable Anatase TiO2 Nanospindles and Their Assembly into Anatase@Titanium Oxynitride/Titanium Nitride-Graphene Nanocomposites for Rechargeable Lithium Ion Batteries with High Cycling Performance," Acs Nano, vol. 4, pp. 6515-6526, Nov 2010.
[30] M. Q. Snyder, S. A. Trebukhova, B. Ravdel, M. C. Wheeler, J. DiCarlo, C. P. Tripp, et al., "Synthesis and characterization of atomic layer deposited titanium nitride thin films on lithium titanate spinel powder as a lithium-ion battery anode," Journal of Power Sources, vol. 165, pp. 379-385, Feb 2007.
[31] Y. Yue, P. Han, X. He, K. Zhang, Z. Liu, C. Zhang, et al., "In situ synthesis of a graphene/titanium nitride hybrid material with highly improved performance for lithium storage," Journal of Materials Chemistry, vol. 22, pp. 4938-4943, 2012 2012.
[32] M. Kaltenbrunner, T. Sekitani, J. Reeder, T. Yokota, K. Kuribara, T. Tokuhara, et al., "An ultra-lightweight design for imperceptible plastic electronics," Nature, vol. 499, p. 458, Jul 2013.