臺灣博碩士論文加值系統

利用塑膠基板搭配有機主動層與介電層製作而成的可撓式有機薄膜電晶體，在未來電子科技產業有非常好的前景。而有機薄膜電晶體具備可撓性、低溫製程、低成本和可大面積製作等優勢，因此在電子產品應用上相當多元，舉凡電子紙顯示器、無線射頻標籤、智慧服飾和大面積感測器等。
在本研究中，主要以探討元件在彎曲狀態下電特性之變化。首先，我們先建立一個可撓式有機薄膜電晶體的標準製程。將元件分別製作於厚度125 μm和25 μm的Polyimide (PI)塑膠基板上，並觀察在此二厚度基板之元件，彎曲4 mm曲率半徑下電特性的變化。接著，比較元件在厚度25 μm的PI塑膠基板上，彎曲不同曲率半徑(4、3、2、和1 mm)並量測其電特性的均勻度。最後，將元件長時間彎曲於曲率半徑1 mm狀態下，比較真空環境與大氣下電特性之差異。
研究結果顯示，厚度較薄之基板，在彎曲相同曲率半徑下，元件電特性的表現較為優秀，亦可承受較小之彎曲半徑；而在不同環境長時間撓曲的狀態下，發現長時間的彎曲狀態下，對元件本身並不會造成明顯劣化；但當大氣中的水氧與彎曲應力交互作用時，則會加速劣化元件的電特性。

Organic semiconductors and polymer dielectrics with plastic substrate recently have been an emerging technology for flexible electronic devices, such as organic thin-film transistors (OTFT). Organic thin-film transistors have the advantages of mechanical properties, low temperature processing, low cost, and large area capability and so have various potential applications such as paper-like displays, radio frequency identification tags, e-textiles, and large area sensors.
In our study, we investigated the transistors’ behavior during bending states, and not just only before and after bending. First, we established a standard manufacturing process of organic thin-film transistors, and chose thickness 125 μm and 25 μm polyimide for our flexible devices’ substrate to examine the electrical characteristics during the same bending radius of 4 mm. Next, we compared the uniformity of characteristics for the devices fabricated on 25 μm polyimide substrate with several bending radii of 4, 3, 2, and 1 mm. Eventually, the devices have stored separately in different environments, vacuum and atmosphere, with a long-term bending state to observe the variations in performance.
The experiment results indicate that thinner substrate could perform more excellent characteristics of OTFT with the same bending radius than that of thicker one, and better durability for smaller bending radii. While the device was in a long-term bending state in the vacuum, the performance wouldn’t deteriorate with time; however, when the device was placed in the air, the mechanical bending would accelerate the degradation of the electrical characteristics.

論文摘要 I
ABSTRACT II
誌謝 III
圖目錄 VII
表目錄 XI
第一章 序論 1
1.1 研究背景 1
1.2 研究動機 3
1.3 論文大綱 4
第二章 有機薄膜電晶體介紹 7
2.1 有機半導體介紹 7
2.1.1 有機半導體材料概論 7
2.1.2 有機半導體Pentacene之特性介紹 9
2.2 有機半導體之傳輸機制 9
2.2.1 Hopping Model 10
2.2.2 Multiple Trapping and Release 11
2.2.3 偏極子(Polaron)和雙偏極子(Bipolaron) 12
2.3 有機薄膜電晶體結構 13
2.4 有機薄膜電晶體之操作模式 14
2.5 電性參數與萃取方式 16
2.5.1 載子移動率(Mobility, μ) 16
2.5.2 臨界電壓(Threshold Voltage, V_th) 18
2.5.3 次臨界斜率(Subthreshold Swing, S.S.) 19
2.5.4 開關電流比(On/Off Current Ratio, I_on/I_Off) 19
第三章 可撓式有機薄膜電晶體之製作 30
3.1 元件製作 30
3.2 製作流程 31
3.2.1 塑膠基板(PI Substrate) 31
3.2.2 載片(holder) 31
3.2.3 閘極(Gate) 32
3.2.4 閘極絕緣層(Gate Insulator Layer) 33
3.2.4 主動層(Active Layer) 34
3.2.6 源極/汲極(Source/Drain) 34
3.3 分析設備介紹及製程機台 35
第四章 有機薄膜電晶體在不同彎曲半徑及環境下對電特性之影響 46
4.1 閘極金屬對有機薄膜電晶體特性的分析 46
4.1.1 閘極金屬(Gate) 47
4.1.2 閘極絕緣層(Gate Insulator Layer) 47
4.1.3 主動層(Active Layer) 47
4.1.4 源極/汲極(Source/Drain) 47
4.1.5 元件電特性分析 48
4.2 不同基板厚度對可撓式有機薄膜電晶體影響 50
4.2.1 有機薄膜電晶體製作在PI塑膠基板流程 50
4.2.2 有機薄膜電晶體基本電特性分析 51
4.2.3 彎曲固定曲率半徑4 mm時不同基板厚度的有機薄膜電晶體基本電特性分析 52
4.3 不同的彎曲半徑對於有機薄膜電晶體電特性之影響 54
4.3.1 有機薄膜電晶體在25 μm PI塑膠基板之製作 55
4.3.2 彎曲不同半徑時有機薄膜電晶體之電特性與分析 55
4.3.3 彎曲不同半徑時有機薄膜電晶體之電特性均勻度的探討 57
4.4 環境與長時間彎曲狀態下對有機薄膜電晶體電特性之影響 59
4.4.1 有機薄膜電晶體製作與量測 59
4.4.2 有機薄膜電晶體長時間在大氣中，平放與彎曲狀態下電特性之探討 59
4.4.3 有機薄膜電晶體長時間在真空下，平放與彎曲狀態下電特性之探討 61
第五章 結論與未來展望 100
5.1 結論 100
5.2 未來工作與展望 101

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