傳統免疫分析儀器(如ELISA、CLIA & FPIA)所須試劑用量較高(25 μL/well × 12 well )、檢測較耗時(1~2.5 hr)、儀器體積較大(>10,000 cm3)且價格很高(>10,000 USD)；所以有必要開發可即時檢測(<5 min)、試劑用量較少(<15 μL)且攜帶方便之微型免疫感測系統。有鑑於此，本論文利用微機電系統(MEMS)技術以開發一種具反射閘極(Reflection grating electrode, RGE)設計之彎曲平板波(Flexural plate wave, FPW)微型感測元件，以應用在各種生醫檢測微系統之研究與發展。與其他聲波元件相比，FPW元件具有較高的質量靈敏度與較低的操作頻率等優點，其缺點是較容易受雜訊影響。針對此點，本論文將加入RGE結構之設計，並探討其對抑制FPW元件之插入損失與雜訊的影響。
本論文運用面型與體型微加工之MEMS製程技術，完成一種具RGE設計之FPW質量感測元件的開發，該元件體積約為0.189 cm3，其主要製程步驟包括六次黃光微影(Photolithography)與九次薄膜沉積的製程。本論文是以反應式射頻磁控濺鍍法沉積高優質C軸(002)取向的氧化鋅(ZnO)壓電薄膜，並以電子蒸鍍方式沉積交指叉式鉻/金電極(Interdigital transducer, IDT)與RGE鋁電極。為了得到最佳化的設計規格，本論文調變輸入端與輸出端IDTs電極間距、IDT電極對數、延遲線間距(Delay line gap)長度與RGE結構，設計與製作出許多不同尺寸的FPW元件；本論文所設計之元件體積最大為0.189 cm3，最小為0.081 cm3，遠小於傳統免疫量測儀器體積。
在最佳化IDT設計規格下，有RGE結構的FPW感測器比沒有RGE結構的FPW元件，具有較低的中心頻率(2∼4 MHz)、較低的插入損失(-11 dB)以及較低的雜訊(<-30 dB)；另外，當測試液體為1 μL的去離子水時，其質量感測靈敏度達-48.3 cm2/g且反應時間僅僅只有5分鐘。以上特性顯示本研究之成果，未來在生醫檢測微系統之研究與發展上具有極高的可應用性。

The conventional medical immunoassays (ELISA/CLIA/FPIA) are not only costly (>10,000 USD), large in size (>10,000 cm3), but also require a vast number of sampling (25 μL/well × 12 well) and long detection time (1~2.5 hr). To develop a biomedical microsensor for the application of portable detecting microsystem, this thesis proposes a flexural plate wave (FPW) microsensor with a novel reflection grating electrode (RGE) microstructure. Comparing to the conventional acoustic microsensors, the FPW based device has higher mass sensitivity, lower operation frequency but higher noise level. To overcome this disadvantages, this study added the RGE microstructure into the design of FPW sensor and investigated its influences on the reduction of insertion loss and noise level.
By using the surface and bulk micromachining technologies, this thesis designed and fabricated FPW-based mass-sensing device with a small volume of 0.189 cm3 and a novel RGE microstructure. The main processing steps adopted in this research include six photolithoghaphies and nine thin-film depositions. In this work, a high figure-of-merit C-axial orientation ZnO piezoelectric thin-film was deposited by a commercial magnetic radio-frequency (RF) sputter system. On the other hand, the gold/chrome interdigital transducer (IDT) and RGE aluminum electrode were deposited utilizing a commercial E-beam evaporator system. For the optimization of design specifications of the FPW devices, the space of input and output IDTs, pair number of IDT, length of delay line gap and with/without RGE design were varied and investigated.
Under the optimized IDT specification, the FPW microstructure presents lower central frequency (2∼4 MHz), insertion loss (-11 dB) and noise level (<-30 dB) than that of the FPW based microsensor without RGE microstructure. In addition, as the sampling volume of the testing DI water is equal to 1 μL, a high mass sensitivity (-48.3 cm2/g) and short responding time (5 min) of the FPW microsensor with RGE design can be achieved in this work. The excellent characteristics mentioned above demonstrated the implemented FPW microsensor is very suitable for the applications of portable biomedical detecting microsystems.

目錄

摘要..……………………………………………………………………. I
Abstract.………………………………………………………...……… III
致謝..………………………………………………………………….... V
目錄..………………………………..………………………………. …VI
圖目錄..……………………………………………………………...… .X
表目錄..…………………………………..………...…...…………….XIV
第一章 緒論……………………………………………………………1
1-1前言………………………………………………………………..1
1-2 研究動機與目的……………………………………………….…4
1-3 文獻回顧……………………………………………………….…6
1-3-1 剪應力(Thickness shear mode, TSM)震盪器……………….6
1-3-2 表面聲波(Surface Acoustic Wave, SAW)感測器………...…7
1-3-3 剪力水平板波(Shear Horizontal Acoustic Plate
Mode, SH-APM)感測器……………………………………8
1-3-4 彎曲平板波(Flexural Plate Wave, FPW)感測器……………9
第二章 彎曲平板波感測器感測理論與反射閘極原理……………..15
2-1 彎曲平板波質量感測之理論推導……………………………...15
2-1-1 彎曲平板波無液體質量負載下之相速度理論推導……...16
2-1-2 彎曲平板波於非黏滯性液體質量負載下之平板波
相速度、質量敏感度以及頻率飄移量之理論推導………..18
2-1-3 彎曲平板波於黏滯性液體質量負載下相速度之理
論推導……………………..……………………………..…20
2-1-4 本論文之彎曲平板波感測器相速度與中心頻率之
計算…………………………………………………………20
2-1-5彎曲平板波感測器於負載去離子水之中心頻率偏
移量計算……………………………………………………23
2-2 壓電效應與壓電薄膜選擇…………………………………...…24
2-3 反射閘極理論………………………………………………...…27
2-3-1反射閘極電性…………………………………………….…27
2-3-2 反射閘極週期…………………………………………...…29
2-3-3 反射閘極對數………………………………………...……30
2-3-4 反射閘極與交指叉式電極間延遲距離之關係…………...30
第三章 具反射閘極之彎曲平板波感測器之設計與實驗方法………32
3-1具反射閘極彎曲平板波感測器之設計…………………………32
3-1-1 底電極圖形之設計規範…………………………………...34
3-1-2 氧化鋅薄膜圖形之設計規範……………………...………34
3-1-3 交指叉式電極圖形之設計規範…………………...………34
3-1-4 反射閘極圖形之設計規範……………………………...…39
3-1-5 背蝕刻孔圖形之設計規範………………………………...39
3-1-6 電化學蝕刻停止接觸電極圖形之設計規範……………...40
3-2 具反射閘極之彎曲平板波感測器製作流程…………………...41
3-2-1 製作流程………………………………………………...…41
3-2-2製作方法與製程參數…………………………………….…43
3-3 彎曲平板波感測器頻率擷取電路的設計……………………...55
3-3-1 混波降頻電路……………………………………………...56
3-3-2 中頻信號放大器…………………………………………...57
3-3-3 正弦波類比信號轉電晶體邏輯電路
(Transistor-transistor logic, TTL)位準電路……………......57
3-3-4 除頻電路…………………………………………………...57
第四章 實驗結果與討論…………………………………………..…59
4-1 具反射閘極之彎曲平板波感測器結構分析…………………...59
4-1-1 氧化鋅壓電薄膜表面結構……………………………...…59
4-1-2 交指叉式電極結構……………………………………...…61
4-1-3 反射閘極結構……………………………………………...63
4-1-4 背後矽蝕刻製程與晶片完成結果圖……………………...66
4-2 彎曲平板波感測器探針量測結果與分析…………………...…67
4-2-1 FPW感測器探針式量測平台簡介……………….……...…67
4-2-2 FPW感測器探針式量測平台結果比較與討論……………68
4-3 彎曲平板波感測器去離子水量測結果與分析……………...…74
4-4 頻率感測電路板的模擬結果…………………………………...79
第五章 結論及未來之展望………………………………………..…81
參考文獻………………………………………………………………..83
附錄……………………………………………………………………..86

[1] 「微機電系統技術與應用」，行政院國家科學委員會精密儀器發展中心，2003。
[2] T. Laurent, F. O. Bastien, J. C. Pommier, A. Cachard, D. Remiens, E. Cattan, “Lamb Wave and Plate Mode in ZnO/silicon and AlN/silicon Membrane Application to Sensors able to Operate in Contact with Liquid,” Sensor and Actuator A, Vol. 87, pp. 26-37, 2000.
[3] S. G. Joshi and B. D. Zaitsev, “Reflection of Ultrasonic Lamb Waves Propagating in Thin Piezoelectric Plates,” Ultrasonics Symposium, pp. 423-426, 1998.
[4] D. S. Ballantine and David Stephen, “Acoustic Wave Sensor:Theory, Design, and Physico-Chemical Applications,” San Diego, Academic Press, Inc., 1997.
[5] R. W. Cernosek, “An Overview of Acoustic Wave Devices for Chemical&Biological Sensing, Biological Detection, and Materials Characterization”, Solid-State Sensor Lecture, Auburn University, Auburn, AL, 2002.
[6] 李其源，蝕刻晶片厚度即時監控之新穎方法，國立台灣大學機械工程研究所博士論文，2004。
[7] 吳德春，薄膜式表面聲波元件之製作與分析，中原大學電子工程學系碩士論文，2002。
[8] D. W. Galipeau, P. R. Story, K. A. Vetelino and R. D.Mileham,“Surface Acoustic Wave Microsensors and Applications,”Smart Mater. Struct. 6, pp. 658-667, 1997.
[9] A. Pohl, “A review of wireless SAW sensors,” IEEE Trans. Ultras.Ferr. Freq. Contr. 47, pp. 317-332 , 2000.
[10] B. Drafts, “Acoustic Wave Technology Sensors,” IEEE Trans. On Microwave Theory and Techniques, Vol. 49, No. 4, 2001.
[11] M. J. Velekoop, “Acoustic Wave Sensors and Their Technology,”Ultrasonics, Vol. 36, pp. 7-14, 1998.
[12] M. E. Motamedi and R. M. White, “Acoustic Sensor in Semiconductor Sensor,” John Wiely & Sons, Inc., New York,1994.
[13] M. S. Weinberg, B. T. Cunningham, C. W. Clapp, “Modeling Flexural Plate Wave Device,” IEEE J. Microelectromechanical Systems, Vol. 9, No.3, pp. 370 – 379, 2000.
[14] 余嘉銘，壓電彎曲平板波生物感測器，國立中正大學電機工程研究所碩士論文，2003。
[15] J. W. Gardner, Vijay k. Varadan and Osama O. Awadelkarim,“Microsensors MEMS and Smart Devices,” John Wiely & Sons,Inc., 2001.
[16] C. K. Campbell, “Surface Acoustic Wave Devices for Mobile and Wireless Communication,” Academic Press, New York, 1998.
[17] 林俊甫，雙埠表面聲波濾波器的模擬與量測，國立成功大學機械工程學研究所碩士論文，2003。
[18] 張逸文，具有高優值C 軸選向氧化鋅壓電薄膜及交指式傳感電極之彎曲平板波元件的研究，國立中山大學電機工程學研究所碩士論文， 2006。
[19] 季君炎，表面聲波元件和積體電路整合之研究，國立台灣大學應用力學研究所碩士論文，2000。
[20] R. H. Tancrell and M. G. Holland, “Acoustic Surface Wave Filters,” Proc. IEEE, Vol. 59, No.3, pp. 393-409, 1971.
[21] 盧明智、黃敏祥，”Op Amp 應用+實驗模擬”，全華科技圖書股份有限公司，87年6月。