近年來隨著工業高度發展，二氧化碳的高排放量除了造成空氣汙染以及溫室效應外，亦導致水質酸化及養殖漁業魚苗存活率下降等問題，因此開發一種高品質之感測系統以即時檢測水中二氧化碳濃度是一個非常重要之研究課題。目前市面上傳統量測水中之氣體感測器在量測時因必頇伴隨商用參考電極(長為 10 cm，直徑為 3 mm 且價格約為4000元)，故具有體積龐大、價格昂貴以及無法即時監控等缺點，因此本論文致力於開發一種可以整合微型固態參考電極之二氧化碳微型感測器，以有效改善上述三種缺點。
首先，本論文利用微機電系統技術開發微型參考電極晶片，該晶片包含電極晶片與封裝晶片兩部分。電極晶片是在矽晶片上沉積鈦/銀金屬薄膜，再利用電化學方式將銀氯化而形成氯化銀薄膜，進而完成銀/氯化銀微型準參考電極晶片之製作；至於封裝晶片則設計有兩個不同尺寸之微矽蝕刻腔體結構，其中一個矽腔體用以填充氯化鉀洋菜膠以作為準參考電極之鹽橋，另一個矽腔體則提供導線與電極晶片之連接通道。本論文利用一般半導體製程設計製作延伸式閘極場效電晶體(Extended Gate Field Effect Transistor, EGFET)，並結合氣體滲透薄膜與固態電解質薄膜製備開發具有高感測靈敏度、元件體積小、低製造成本之二氧化碳微型感測器，相關製程步驟總共包含六道黃光微影製程及九道薄膜沉積。最後，本研究中將探討分析微型參考電極注膠面積尺寸、電晶體之通道寬長比對二氧化碳微型感測器之特性影響，進而獲得最佳特性表現之元件尺寸設計。
本論文所開發之微型參考電極尺寸為 9 mm×6 mm×0.5 mm，經量測結果證實其補償電位(Offset Voltage)在 30,000 秒測詴時間下呈現非常低且穩定之值(-3.0 mV)、以及可呈現與商用參考電極幾乎一樣穩定的 CV 曲線；而製作完成之EGFET 二氧化碳微型感測器(含微型參考電極晶片)之尺寸為 3 cm×2 cm×2 mm(感測區域之面積為 1 mm×1 mm)，根據量測結果顯示，於 0.25~50 mM濃度量測範圍下，元件之感測靈敏度與線性度最高分別可達 44.4 mV/dec 與 98.37%，感測響應時間約為100 sec，以上三種特性表現皆比國際上其他研究還高，故可證明具積體化微型參考電極之 EGFET 二氧化碳微型感測器，具有體積小、性能佳及可即時監控之優點。

　　In recent years, high carbon dioxide emissions not only result in serious air pollution and greenhouse effect, but also cause water acidification and decrease the survival rate of fry in aquaculture. Therefore, to develop a high-quality sensing system for real-time detecting the concentration of carbon dioxide in water is a very important research topic. The conventional carbon dioxide detectors in water have caused the detection inconvenient because of their large dimension, high fabrication cost and without real-time monitoring function. To improve these disadvantages, this thesis aims to develop a carbon dioxide microsensor integrated with an all-solid-state micro reference electrode.
　　This thesis utilizes micro electro mechanical systems (MEMS) technology to develop micro reference electrode including electrode chip and packaging chip. One wafer of this module is defined as electrode chip. It has titanium/silver membranes deposited on the silicon wafer and then chloridizes the silver membrane by using electrochemical method. So it is namely silver/silver chloride quasi-reference electrode. Another wafer is called as packaging chip and it has two bulk micromachined silicon cavities for filling potassium chloride agarose as a quasi-reference electrode salt bridge and another for external conductors connection. Next, the thesis implements an extended gate field effect transistor (EGFET) with gas permeable membrane and solid electrolyte membrane for development of a high sensitivity, small size and low cost carbon dioxide microsensor. The total main processing steps of the proposed microsensor includes six photolithography and nine thin-film deposition processes. In addition, the influences of the filling cavity size of micro reference electrode and the channel width/length ratio of EGFET on the sensing performances of presented microsensor are also investigated in this study.
　　The chip size of the implemented micro reference electrode is 9 mm×6 mm×0.5 mm. It has a very low and stable offset voltage (-3.0 mV in 30,000 seconds). Furthermore, a CV curve of the packaged reference electrode is same stable with commercial reference electrode. Also, the chip size of the implemented carbon dioxide microsensor with micro reference electrode is 3 cm×2 cm×2 mm and the sensing area is 1 mm×1 mm. As the carbon dioxide concentration varies from 0.25 mM to 50 mM, a very high sensitivity (44.4 mV/dec) and sensing linearity (98.37%) of the proposed EGFET microsensor can be demonstrated. In addition, the response time of the presented carbon dioxide microsensor is only about 100 seconds. Therefore, this thesis proves a carbon dioxide micro gas sensor with integrated micro reference electrode has three advantages such as small dimension, low fabrication cost and real-time monitoring function.

誌謝............................................................................................................................... i
摘要................................................................................................................................ii
Abstract ........................................................................................................................ iv
目錄.............................................................................................................................. vi
圖目錄.......................................................................................................................... ix
表目錄....................................................................................................................... xiii
第 1 章 緒論................................................................................................................ 1
1-1 前言................................................................................................................... 1
1-2 研究動機........................................................................................................... 2
1-3 實驗方法及論文架構....................................................................................... 5
第 2 章 原理介紹........................................................................................................ 7
2-1 電化學簡介....................................................................................................... 7
2-1-1 電極反應.................................................................................................... 8
2-1-2 質量傳遞.................................................................................................... 9
2-2 交流阻抗分析................................................................................................... 9
2-2-1 電化學系統等效電路.............................................................................. 11
2-2-2 擴散阻抗.................................................................................................. 15
2-2-3 擬電路元件之電化學性質...................................................................... 17
2-3 循環伏安法..................................................................................................... 19
2-4 感測器種類..................................................................................................... 21
2-4-1 離子選擇電極.......................................................................................... 21
2-4-2 離子感測場效電晶體.............................................................................. 22
2-4-3 延伸式閘極感測場效電晶體.................................................................. 24
2-5 延伸式閘極感測場效電晶體原理介紹......................................................... 25
2-5-1 吸附鍵結模型............................................................................................ 26
2-5-2 延伸式閘極感測場效電晶體工作原理.................................................... 27
第 3 章 元件設計與製作.......................................................................................... 30
3-1 微型參考電極元件......................................................................................... 30
3-1-1 氯化銀電極晶片的設計與製作流程...................................................... 30
3-1-2 KCl-gel 封裝晶片的光罩設計 ................................................................ 35
3-1-3 KCl-gel 封裝晶片的製作流程 ................................................................ 36
3-1-4 微型參考電極之封裝與電性連接.......................................................... 42
3-2 延伸式閘極感測場效電晶體元件................................................................. 44
3-2-1 延伸式閘極場效電晶體結構與光罩佈局設計...................................... 44
3-2-2 延伸式閘極場效電晶體製程整合設計 .................................................. 47
3-2-3 詳細製程步驟與參數 .............................................................................. 48
3-3 固態電解質薄膜配製 ..................................................................................... 54
3-4 氣體滲透薄膜配製 ......................................................................................... 55
第 4 章 結果與討論.................................................................................................. 58
4-1 微型參考電極電化學分析............................................................................. 58
4-1-1 電位穩定度與補償電位.......................................................................... 58
4-1-2 交流阻抗分析.......................................................................................... 61
4-1-3 循環伏安曲線.......................................................................................... 63
4-2 延伸式閘極場效電晶體................................................................................. 71
4-2-1 延伸式閘極場效電晶體量測分析.......................................................... 72
4-3 二氧化碳微型感測器特性量測分析............................................................. 74
4-3-1 感測靈敏度與線性度分析...................................................................... 75
4-3-2 感測遲滯電壓分析.................................................................................. 80
第 5 章 結論與未來展望.......................................................................................... 83
5-1 結論................................................................................................................. 83
5-2 未來展望......................................................................................................... 84
參考文獻...................................................................................................................... 85

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