臺灣博碩士論文加值系統

離子感測場效電晶體( Ion-sensitive Field Effect Transistor )是由Bergveld在1970年首先提出，由於它的尺寸小，反應速度快、可承受外部應力，且與現今的CMOS製程相容，所以在現在的感測元件開發中具有相當大的潛力。
但是由於缺乏一個穩定且微小化的固態參考電極，使得ISFET的應用受到很大的限制。為了要實現一個最簡單且小型結構的ISFET，在微小化的技術上，必須要整合一個固態參考電極在單一ISFET晶片上，不需要額外再使用到REFET或玻璃電極。
從過去的實驗結果可知道，NafionTM混合Polymer的結構具有使REFET的感測層維持在一個固定的電位且保護它不受離子的干擾的效果。在本篇論文中，我們成功地以Polyimide/ NafionTM的結構應用到固態參考電極的表面修飾上，使得固態參考電極因為金屬/溶液接面產生的不穩定電壓被消除。由實驗結果可看出，令人困擾的電壓不穩問題，大幅地獲得改善。一個單一的ISFET整合固態參考電極在不需搭配REFET或玻璃參考電極的情況下，對氫離子的靈敏度可達到56.5 mV/pH而且輸出電壓也展現相當優秀的重線性及線性度，且對鈉離子的靈敏度只有7.5 mV/pNa的低靈敏度。以Polyimide/ NafionTM塗佈的固態電極作為參考電極，在24小時下的量測結果顯示，飄移速率更可達到每小時1.05 mV的低程度飄移率。

ISFET( Ion-sensitive Field Effect Transistor ) was first developed by Bergveld in 1970s, and because of its small size, fast response, rigidity and compatibility with standard CMOS process, ISFET is an attractive candidate of modern sensor device.
Due to the lack of a stable and miniaturized solid-state reference electrode, the applications of ISFET will be restricted seriously. In order to realize the single ISFET integrated with the simple and compact structure solid-state reference electrode by miniaturized technology, the simple and compact structure of ISFET sensor was fabricated without the additional REFET or glass reference electrode.
From the previous experimental results, we can know the NafionTM mix PR structure can maintain a constant voltage for the sensing layer of REFET and prevent it from the disturbance of ions. In this thesis, we successfully apply the Polyimide/ NafionTM structure to modify the surface of the solid-state reference electrode. The unstable voltage generated from the thermodynamically undefined metal/electrolyte interface can be eliminated. From the experimental results, it is obviously that the troublesome and unstable problem can be greatly improved. Without REFET arrangement in differential measurement or glass reference electrode, the H+ sensitivity of single ZrO2-pH-ISFET integrated with solid-state reference electrode still can reach to 56.5 mV/pH and the output voltage also exhibit high reproducibility and linearity. Furthermore, the Na+ sensitivity can reduce to 7.5 mV/pNa. During a measurement period of 24 hours, the reference electrode with Polyimide/Nafion coating shows a low averaged drift rate of 1.05mV/h.

Chapter 1 Introduction
1.1 The Importance of pH detection 1
1.2 Techniques for pH detection 1
1.3 The pH glass electrodes 2
1.4 The ISFET-based pH sensors 3
1.5 The importance of reference electrode 5
1.6 Solid-state reference electrode integrated with ISFET 6
1.7 Motivation of this work and thesis organization 7
1.8 References 8
Chapter 2 Theory Description
2.1 Definition of pH 10
2.2 Fundamental principles of ISFET 10
2.2.1 From MOSFET to ISFET 11
2.2.2 The oxide-electrolyte interface 13
2.2.3 Theory for the pH sensitivity of ISFET 18
2.3 Non-ideal phenomena of ISFET 19
2.3.1 Hysteresis 20
2.3.2 Drift 20
2.3.3 Dispersive transport 21
2.3.4 Physical model for drift 23
2.4 Summary 25
2.5 References 26
Chapter 3 Experiment and Measurement
3.1 Introduction 29
3.2 The characteristics of the Polyimide and Nafion 29
3.2.1 Polyimide 29
3.2.2 Nafion 30
3.3 Fabrication process flow of ISFET 30
3.4 Key steps illustration 32
3.4.1 Gate region formation 32
3.4.2 Sensing layer deposition 32
3.4.3 Polyimide/Nafion membrane-based reference electrodes 33
3.5 Packing and measurement system 34
3.5.1 Current-Voltage (I-V) measurement set-up 34
3.5.2 Current-Voltage (I-V) measurement set-up with solid-state reference electrodes 35
3.5.3 Drift measurement set-up with solid-state reference electrodes 35
3.6 References 36
Chapter 4 Results and Discussions
4.1 Introduction 37
4.2 Solid-state reference electrode integrated with ISFET 37
4.2.1 Solid-state reference electrode 37
4.2.2 The glass reference electrode (GRE) 39
4.3 The experimental results and discussion of solid-state reference electrodes 39
4.3.1 Potential reproducibility and linearity 39
4.3.2 pH sensitivity 41
4.3.3 Drift characteristics 42
4.4 Conclusions 43
4.5 References 44
Chapter 5 Future Work 45

chapter 1
[1] Y. Q. Miao, J. R. Chen and K. M. Fang, “New technology for the detection of pH”, J. Biochem. Biophys. Methods, vol. 63, pp. 1-9, 2005.
[2] P. Bergveld, “ISFET, Theory and Practice”, in IEEE Sensor Conference, Toronto, Oct. 2003.
[3] P. Bergveld, “Development of an ion sensitive solid-state device for neurophysiological measurements”, IEEE Trans.Biomed. Eng.,vol. BME-17, p.70, 1970.
[4] Paul A. Hammond, Danish Ali, and David R. S. Cumming, ”Design of a Single-Chip pH Sensor Using a Conventional 0.6-um CMOS Process.”, IEEE Sensors Journal, vol. 4, no. 6, Dec, 2004.
[5] Kow-Ming Chang, Kuo-Yi Chao, Ting-Wei Chou, and Chin-Tien Chang, “Characteristics of Zirconium Oxide Gate Ion-Sensitive Field-Effect Transistors”, Jpn. J. Appl. Phys. 46, pp. 4333-4337, 2007.
[6] Lin, Y-S., Puthenkovilakam, R., and Chang, J. P., “Dielectric property and thermal reproducibility of HfO2 on silicon”, Applied Physics Letters, 81(11), pp. 2041-2043, 2002.
[7] A. Simonis, H. Luith, J. Wang, M.J. Sch¨oning, New concepts of miniaturized reference electrodes in silicon technology for potentiometric sensor systems, Sens. Actuators B 103, pp. 429-435, 2004.
[8] H. Suzuki, T. Hirakawa, S. Sasaki, I. Karube, “Micromachined liquidjunction Ag/AgCl reference electrode”, Sens. Actuators B 46, pp. 146-154A, 1998.
[9] Eine, et al., “Towards a Solid-State Reference Electrode,” Sensors and Actuators B, 44, pp. 381-388, 1997.

chapter 2
[1] Y. Q. Miao, J. R. Chen and K. M. Fang, “New technology for the detection of pH”,J. Biochem. Biophys. Methods, vol. 63, pp. 1-9, 2005.
[2] P. Bergveld, “Thirty years of ISFETOLOGY What happened in the past 30 years and what happen in the next 30 years”, Sensors and Actuators B, vol. 88, pp. 1-20, 2003.
[3] H.K. Liao, et al. ”Study on pHpzc and surface potential of tin oxide gate ISFET”, Materials Chemistry and Physics, vol. 59, pp.6-11, 1999.
[4] P. Bergveld, “ISFET, Theory and Practice”, in IEEE Sensor Conference, Toronto,Oct. 2003.
[5] R.E.G. van Hal et al. , “A general model to describe the electrostatic potential at electrolyte oxide interface”, Advance in Colloid and Interface Science, vol.69, pp.31-62, 1996.
[6] Miao Yuqing , Guan Jianguo, Chen Jianrong, “Ion sensitive field transducer-based biosensors”, Biotechnology Advances, vol. 21, pp.527-534, 2003.
[7] W. M. Siu, R. S. C. Cobbold, “Basic Properties of the Electrolyte-SiO2-Si System: Physical and Theoretical Aspects”, IEEE Transactions on Electron Device, vol. ED-26, NO. 11, Nov., 1979.
[8] R.E.G. van Hal, J.C.T. Eijkel, P.Bergveld, “A novel description of ISFET sensi- tivity with the buffer capacity and double layer capacitance as key parameters”, Sensors and Actuators B, vol. 24, pp.201-205, 1995.
[9] Tadayuki Matsuo, Masayoshi Esashi, ”Methods of ISFET Fabrication”, Sensors and Actuators, vol. 1, pp.77-96, 1981.
[10] Imants R. Lauks, Jay N. Zemel, “The Si3N4/Si Ion-Sensitive Semiconductor Electrode ”, IEEE Transactions on Electron Devices, vol. ED-26, no.12, pp. 1959- 1964, Dec., 1979.
[11] J.C. Chou, C.Y. Weng, “Sensitivity and hysteresis effect in Al2O3 gate pH- ISFET ”, Materials Chemistry and Physics, vol. 71, pp.120-124, 2001.
[12] P.D. van der Wal et al. ,”High-K Dielectrics for Use as ISFET Gate Oxide”, in Sensors, Proceedings of IEEE, 2004.
[13] H.K.Liao et al.,” Study of amorphous tin oxide thin films for ISFET applications”, Sensors and Actuators B, vol.50, pp.104-109, 1998.
[14] Luc Bousse, Piet Bergveld, “The Role Of Buried OH Sites In The Response Mechanism Of Inorganic-Gate pH-Sensitive ISFETs”, Sensors and Actuators, vol. 6, pp.65-78, 1984.
[15] P. Woias, L.Meixner, P. Frostl, ”Slow pH response effects of silicon nitride ISFET sensors”, Sensors and Actuators B, vol. 48, pp.501-504, 1998.
[16] J.C. Chou, K.Y. Huang, J.S. Lin, ”Simulation of time-dependent effects of pH-ISFETs ” Sensors and Actuators B, vol. 62, pp.88-91, 2000.
[17] Luc Bousse et al. , ”Comparison of the hysteresis of Ta2O5 and Si3N4 pH-sensing insulators”, Sensors and Actuators B, vol.17, pp. 157-164, 1994.
[18] J.C. Chou, Y.F. Wang, ”Preparation and study on the drift and hysteresis properties of the tin oxide gate ISFET by the sol-gel method”, Sensors and Actuators B, vol.86, pp.58-62, 2002.
[19] S. Jamasb, S. D. Collins, R. L. Smith, ”A Physical Model for Threshold Voltage Inreproducibility in Si3N4-Gate H+-Sensitive FET’S ( pH ISFET’s )”, IEEE Transactions on Electron Devices, vol. 45, no. 6, pp.1239-1245, Jun, 1998.
[20] H. Scher, Elliott W. Montroll, ”Anomalous transit-time dispersion in amorphous solid”, Physical Review B, vol. 12, no.6, pp.2455-2477, Sep., 1975.
[21] G. Pfister, H. Scher, ” Time-dependent electrical transport in amorphous solid: As2Se3”, Physical Review B, vol. 15, no. 4, pp.2062-2082, Feb., 1977.
[22] J. Kakalios, R. A. Street, W. B. Jackson, ”Stretched-Exponential Relaxation Arising from Dispersive Diffusion of Hydrogen in Amorphous Sillicon”, Physical Review Letters, vol. 59, no.9, pp.1037-1040, Aug. 1987.
[23] 吳浩青, 李永舫, ”電化學動力學”, 科技圖書公司, 2001年2月.
[24] S. Jamasb, S. D. Collins, R. L. Smith, ”A Physically-based Model for Drift in Al2O3-gate pH ISFETs ” in International Conference on Solid-State Sensors and Actuators Chicago, June, 1997.
[25] S. Jamasb, S. D. Collins, R. L. Smith, ”A physical model for drift in pH ISFET ”, Sensors and Actuators B, vol. 49, pp.146-155, 1998.
[26] George T. Yu, S.K. Yeh, ”Hydrogen ion diffusion coefficient of silicon nitride thin films”, Applied Surface Science, vol. 202, pp.68-72, 2002.

chapter 3
[1] M. Sato, T. Yamamoto, M. Takeuchi, K. Yamanouchi, Humidity sensitivity of Lamb waves on composite polyimide:ZnO:Si3N4 structure, Jpn. J. Appl. Phys. 32 Part 1,pp. 2380-2383, 1993.
[2] John Payne ”Nafion® - Perfluorosulfonate Ionomer”, April, 2005 from http://www.psrc.usm.edu/mauritz/nafion.html .
[3] Daivd T.V. Anh, W. Olthuis, P. Bergveld, ”Hydrogen peroxide detection with improved selectivity and sensitivity using constant current potentiometry”, Sensors and Actuators B, vol. 91, pp. 1-4, 2003.
[4] Patrick J. Kinlen, John E. Heider, David E. Hubbard, ”A solid-state pH sensors based on a Nafion-coated iridium oxide indicator electrode and a polymer-based silver chloride reference electrode” Sensors and Actuators B, vol. 22, pp. 13-25, 1994.
[5] J.P. Tsao, C.W. Lin, ”Preparations and Characterizations of the Nafion/SiO2 Proton Exchange Composite Membrane”, Journal of Materials Science and Engineering, vol. 34, No. 1, pp. 17-26, 2002.
[6] K. M. Chang, K. Y. Chao, T. W. Chou, and C. T. Chang, ”Characteristics of Zirconium Oxide Gate Ion-sensitive Field-Effect Transistors” Japanese Journal of Applied Physics Vol. 46 No. 7A pp. 4334-4338, 2007.
[7] Paik-Kyun Shin, ”The pH-sensing and light-induced drift properties of titanium dioxide thin films deposited by MOCVD”, Applied Surface Science, vol. 214, pp. 214-221, 2003.

chapter 4
[1] I-Yu Huang, Ruey-Shing Huang, “Fabrication and characterization of a new planar solid-state reference electrode for ISFET sensors”, Thin Solid Films, vol. 406, pp.255-261, 2002.
[2] I-Yu Huang, Ruey-Shing Huang, Lieh-Hsi Lo, “Improvement of integrated Ag/AgCl thin-film electrodes by KCl-gel coating for ISFET applications”, Sensors and Actuators B, vol. 94, pp.53-64, 2003.
[3] Chen Dong-chu, et al., ”Preparation of Nafion Coated Ag/AgCl Reference Electrode and Its Application in the pH Electrochemical Sensor”, Journal of Analysis Science, vol. 21, pp. 432-434, Aug., 2005.
[4] Z. Yule, Z. Shouan and L. Tao, “Drift characteristic of pH-ISFET output”, Chin. J. Semicond. 15, pp. 838-843, 1994.
[5] K. M. Chang, K. Y. Chao, T. W. Chou, and C. T. Chang, ”Characteristics of Zirconium Oxide Gate Ion-sensitive Field-Effect Transistors” Japanese Journal of Applied Physics Vol. 46 No. 7A pp. 4334-4338, 2007.