臺灣博碩士論文加值系統

微熱導感測器（μ－TCD）的技術雖己被成功的發展，惟它的精度仍不足以量測微小的變化。為了改善μ-TCD 之靈敏度及檢測精度，需重新探討設計熱阻線的形式、絕熱層的材質、及其氣體流道的結構等因素。
本論文主要是探討熱阻線形式、絕熱層材料及氣體流道對微熱導感測器性能之影響。在本實驗中，除將鎳加熱線之線寬縮小、長度加長外，亦在形狀上加以修改。並將絕熱層的材質改用高分子的polyimide、氮化矽(Si3N4)及更薄的Pyrex玻璃來取代原來40μm的Pyrex玻璃。且亦改變感測器之結構，來取代原設計之絕熱層下方鏤空之結構，讓下層氣體流道和上層具有同樣的結構。
在本研究內已利用陽極接合、曝光顯影技術、蝕刻技術、膠合技術及物理蒸鍍等多項技術，製造出五種具相異之熱阻線形式、絕熱層材料及氣體流道結構的微熱導感測器。實驗結果發現，較大的電阻值會有較靈敏的輸出值。高電阻值的電阻在同樣的溫差下，會有較大的電阻值變化，故新的熱阻線形式可以提高感測器輸出之靈敏度。在低電壓時，雖然達至熱平衡所需之時間較短，但電流的輸出相當不穩定。在高電壓下，達至熱平衡所需的時間較久，但只要達至熱平衡，輸出之電流值都相當穩定，顯示此三種材質的絕熱效果都不錯。但三種絕熱層材質中以Polyimide最快達到熱平衡，且電流輸出最為穩定，所以可斷定Polyimide之絕熱效果最佳，且材料又較易取得。量測結果亦顯示，上、下都有氣體流道結構者，較只有上層有氣體流道結構者，多熱傳導走的熱能約為 ，佔實際全部散失熱的 1/9左右，與理論值1/8只有些微差距，顯示上、下都有氣體流道結構者，較只有下方有氣體流道的結構者，提高了11%的檢測精度。

A Miniaturized Thermal Conductivity Detector (TCD) has been developed and commercially available, but the sensitivity in measurement is not enough for detecting a small concentration change in gases. The objective of this study is to improve the sensitivity and accuracy of Micro-TCD by changing the structural design and thermal insulator of the detection chamber. The effects of the configuration of sensing element, the thermally insulating materials and the position of sensing element inside the microchannel on the characteristics of μ-TCD were studied.
In this study, the configuration, the width, and the length of the heating element were changed to increase the electrical resistance of the heating element. Next, the thermal insulator layer, the 40μm thick Pyrex glass, is replaced by other insulating materials, Si3N4, the thinner Pyrex glass and KaptonR polyimide film, to make it more effective. Then the original gas channel was redesigned. The sensing element is suspended in the middle of a microchannel etched on silicon wafers. Carrier gas can flow through both sides of the sensing membrane.
Experimental results showed that sensitivity ofμ-TCD can be improved by making the sensing element having high resistance. Photolithography, wet-etching, PVD, anodic-bonding, and wire-bonding techniques were used to fabricate severalμ-TCDs having different configuration of sensing element, thermal insulator, and microchannel structure. For high driving voltage, the time required for μ-TCD to reach steady state is longer and the output signal is much more stable in compare with low driving voltage. Results also showed that the Polyimide has the best effect insulating effect among all the insulating materials used. Calculation based on the experimental data showed that more thermal energy about , was dissipated by a μ-TCD with the heating element suspended in the middle of a microchannel etched on silicon wafers. This increasing amount of thermal energy dissipation, account for one-ninth of total thermal energy dissipated, can improve the accuracy of measurement by 11%.

中文摘要…………………………………………………………………..Ⅰ
英文摘要……………………………………………………………………Ⅱ
誌 謝………………………………………………………………………Ⅳ
目 錄………………………………………………………………………Ⅴ
圖索引………………………………………………………………………Ⅷ
表索引………………………………………………………………………Ⅹ
第1章 緒論…………………………………………………………………1
第2章 原理…………………………………………………………………8
2.1感測原理…………………………………………………………8
2.2微熱導感測器之設計原理…………………………………….12
2.2 1 熱阻線材質及樣式之設計……………………………..12
2.2.2 絕熱層材質之選擇與感測室的設計………………….17
2.2.3 氣體流道的設計…………………………………… …19
2.2.4 惠斯登電橋…………………………………………….20
2.3 微熱導感測器之熱傳分析…………………………………….21
2.4 微型加工製造技術…………………………………………….27
2.4.1 晶片的清洗…………………………………………….28
2.4.2 曝光及顯影…………………………………………… 30
2.4.3蝕刻技術…………………………………………………31
2.4.3.1 溼式蝕刻…………………………………….31
2.4.3.2 乾式蝕刻…………………………………….36
2.4.4薄膜之生長………………………………………………37
2.4.4.1熱蒸鍍法(Thermal deposition)……………38
2.4.4.2 化學蒸鍍法(CVD)…………………………… 39
第3章 實驗方法…………………………………………………………..42
3.1 實驗設備…………………………………………………… … 42
3.2氣體流道的蝕刻………………………………………………. 45
3.3 不同絕熱層之微熱導感測器的製作步驟…………………….47
3.3.1 Polyimide………………………………………………47
3.3.2 氣化矽（Si3N4）……………………………………… 51
3.3.3 pyrex glass……………………………………………53
3.4 組裝…………………………………………………………….54
3.5 測試項目及步驟……………………………………………….54
3.5.1 電阻的測試…………………………………………….54
3.5.2 電流穩定之時間測試………………………………….55
3.5.3 絕熱層下方外殼之溫度測試………………………….56
第4章 製作結果與測試………………………………………………….57
4.1絕熱層為POLYIMIDE之微熱導感測器………………………….57
4.2 絕熱層為（SI3N4）之微熱導感測器………………………….63
4.3 絕熱層為PYREX GLASS之微熱導感測器……………………….65
4.4 組裝…………………………………………………………….66
4.5電阻測試……………………………………………………….67
4.6電流穩定之時間測試………………………………………….71
4.7絕熱層下方外殼之溫度測試………………………………….75
第5章 結論………………………………………………………………..80

1.柯賢文，「微氣相層析儀」，科儀新知，第十九卷，第六期，第26-35 頁，民國87年
2.Edward, S. and Kolesar, Jr., “Review and Summary of a Silicon Micromachined Gas Chromatography System”, IEEE Transactions On Components, Packaging, And Manufacturing Technology-Part B, Vol. 21, No.4, pp324-328 (1998).
3.Hobart, H. and Lynne, L., “Instrumental Methods of Analysis”, Wadsworth Publishing Company, California, pp.552-558 (1988)
4.Jerman, J. H., “A Miniature Thin-Film Thermal Conductivity Detector for an Integrated Gas Chromatograph”, Ph.D. Thesis, Department of Electrical Engineering, Stanford University, U.S.A. (1981).
5. Grob, R.L. “Modern Practice of GC”, pp.225-231 (1985)
6. 林東威，「微熱導感測器之研製」，碩士學位論文，台灣科技大學，
第7-16頁，民國88年
7.Sevcik, J., “Detectors in Gas Chromatography”, Elsevier Scientific Publishing Company, New York, PP.39-42 (1976)
8.Meijer, G.C.M. and Herwaarder, A.W., “Thermal Sensors”, Institute of
Physics Publishing, Bristol and Philadephia, pp.7-13 (1994)
9.Weast, R.C., “CRC Handbook of Chemistry and Physics”, Cleveland, CRC Press (1974)
10Chopra, K.L., “Thin Film Phenomena”, McGraw Hill, New York, pp.349-355 (1969)
11.Van Putten, A.F.P. “A Constant Voltage Constant Current Wheatstone Bridge Configuration”, Sensors and Actuators, Vol. 13, pp.103-109 (1988)
12.Rosie, D. M. “Quantitation of Thermal Conductivity Detectors”, Journal of Chromatographic Science, Vol. 11, pp.237~250 (1973)
13.林育生，「積體電路技術在矽基微機械加工之應用（一）」，機械工業雜誌，第201-210頁，民國八十六年
14.Madou, Mac., “Fundamentals of Microfabrication”, Boca Raton, New York, pp.1-11, pp.97-117, pp.163-177 (1997)
15.Williams, K. R. “Etch Rates for Micromachining Processing”, Journal of Microelectromechanical systems, Vol.5, No.4, pp.256~269 (1996)
16.Van Gelder, W. “The Etching of Silicon Nitride in Phosphoric Acid with Silicon Dioxide as a Mask”, Retention of Fluoride by Silicon, Vol.114, No.8, pp.869-875
17.Seidel, H., “Anisotropic Etching of Crystalline Silicon in Alkaline Sol-utions”, I. Orientation Dependence and Behavior of Passivation layers”, J. Electrochem. Soc., Vol. 137, No.11, pp.3612-3631 (1990)
18. 曾鴻輝，「單晶矽之非等向性化學蝕刻技術」，電子發展月刊，第140期，第1~12頁，第141期，第28~36頁，民國78年
19. Vossen, J. L. “Thin Film Process”, Harcourt Brace Jovanovich, New York (1991)
20.Robbins, H. and Schwartz, B., “Chemical Etching of Silicon; Part I.”, J. Electrochem. Soc., Vol. 106, pp.505-508 (1959)
21.吳東權等，「微機電系統之技術現況與發展」， 機械工業雜誌，第116-125頁，民國八十六年八月。
22.Cozma, A. and Puers, B., “Characterization of Electrostatic Bonding of Silicon and Pyrex Glass”, J. Micromech. Microeng., pp.98-102 (1995).
23.Kovacs, G.T.A. “Silicon Micromachining”, Analytical Chemistry News and Features, p.p.407~412 (1996)
24.陳克紹、曹永偉，薄膜技術，第153~196頁，台北，金文圖書有限公司，民國七十五年。
25.Despont, M., Gross, H., Arrouy, F., Stebler, C., and Staufer, U., "Fabrication of a Silicon-Pyrex-Silicon Stack by a.c. Anodic Bonding", Sensors and Actuators, Vol. A55, pp.219-224 (1996)