現今在許多電子產品中，記憶體扮演著非常重要的角色，隨著電子產品逐漸變得輕薄短小，電子元件尺寸的微小化成為目前所面臨的挑戰。為了解決尺寸縮小的問題，以電阻轉換方式的新型記憶體越來越受到關注，其原因為具有簡單結構、快速的寫入電壓以及良好的尺寸可調性。在先前的研究上，DNA高分子聚合物在電阻式記憶體的應用上具有很好的發展潛力，因此為了更進一步的應用，了解DNA 元件在不同尺寸下的特性為重要的課題。
本篇論文中，我們研究以DNA高分子聚合物為主體的電阻式隨機儲存記憶體的特性。第一個部分，我們探討元件面積尺寸對電性的影響，製作出兩種面積差異900倍的元件並且進行特性分析，包含寫入及抹除電壓統計分析以及開關電流比，並探討兩種元件的電流傳導機制。第二個部分，我們探討不同DNA薄膜厚度對電性的影響，我們製作出4種不同DNA薄膜厚度的元件，其範圍從50nm到200nm，並且分析與比較數種電性。我們也藉由掃描式電子顯微鏡(SEM)觀察及討論電阻絲在DNA材料中的形成機制。我們的研究提供了DNA元件在不同尺寸下的特性探討，可用於DNA記憶體元件的設計與應用。

Memory devices play important roles in many electrons in the modern era. As the electronics have evolved to be smaller and lighter, down-scaling of devices becomes a challenging issue. To resolve the issue, new types of memory devices based on resistive switching has attracted increasing attention due to simpler structure, fast writing-speed and scalability. Previously deoxyribonucleic acid (DNA) biopolymer has been demonstrated as a promising material for resistive switching memory devices. It is important to study the properties at the different device scales for advanced applications.
In this study, we investigate properties of DNA biopolymer-based resistive random access memory(RRAM). In the first part, we study the effect of device area on the electrical properties. Two sizes of devices, with area difference by a factor of 900, are fabricated and measured. The statistics of set/reset voltages and On/Off current ratio are characterized and analyzed. Then the current conduction mechanisms are discussed for devices with different sizes. In the second part of this study, we examine the effect of film thickness on the electrical properties. DNA biopolymer layer with four different thickness, ranging from 50nm to 200nm, are fabricated and the IV characteristics are analyzed. The performances are evaluated and compared by many electrical properties and the mechanisms are discussed. The filament formation in the DNA biopolymer matrix is examined by scanning electronic microscope (SEM). Our study provides a systematic investigation on the scaling properties of DNA biopolymer-based memory devices, which can be used for design guidelines for more advanced implementation。

致謝 I
摘要 II
Abstract III
目錄 IV
圖目錄 VI
表目錄 IX
第一章 緒論 1
1.1 前言 1
1.2 電阻式記憶體簡介 2
1.2.1 電阻式記憶體的發展 2
1.2.2 電阻式記憶體的機制 3
1.3 電極與介電質傳導機制 5
1.3.1 電極限制傳導機制(electrode-limited conduction mechanisms) 5
1.3.2 塊材限制傳導機制(Bulk-limited conduction mechanism) 7
1.4 有機材料電阻式記憶體簡介 10
1.5 DNA高分子材料介紹與應用 10
1.6 研究動機 13
第二章 實驗方法 14
2.1 材料製備 14
2.1.1 DNA-CTMA合成製備 14
2.2 記憶體元件的製作 15
2.2.1 垂直式元件製成 15
2.2.2 平面式元件製成 16
2.2.3 量測儀器 18
第三章 元件特性量測 22
3.1 不同元件面積之特性分析 22
3.1.1 電流-電壓特性 22
3.1.2 開關電流比(On/Off Current Ratio)分析 25
3.1.3 寫入電壓(Vset)及抹除電壓(Vreset)分析 27
3.1.4 電流傳導機制分析 29
3.2 小面積元件之特性分析 31
3.2.1 開關電流比(On/Off Current Ratio)分析 31
3.2.2 寫入電壓(Vset)及抹除電壓(Vreset)分析 34
3.2.3 寫入限制電流分析 36
3.2.4 電流傳導機制分析 37
第四章 電阻轉換機制驗證及討論 39
4.1 電阻轉換機制假設模型 39
4.2 銀電阻絲在DNA-CTMA薄膜中之形貌 41
第五章 結果與未來展望 44
參考文獻 45

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