多通道陣列延伸式閘極場效電晶體應用於氯離子感測器之研製

Study and Fabrication on Multi-Array Extended-Gate Field-Effect Transistor Chloride Ion Sensitive Sensors

洪大祐(Da-You Hong) ； 李習文(His-Wen Lee) ； 鍾文耀(Wen-Yaw Chung) ； 江榮隆(Jung-Lung Chiang) ； 鄭建業(Chean-Yeh Cheng)

《先進工程學刊》 5卷4期 (2010/10) Pp. 288-297

https://doi.org/10.29948/JAE.201010.0002

摘要

本研究係製備以銦錫氧化物(Indium Tin Oxide, ITO)玻璃及氮化鋁／銦錫氧化物(AlN/ITO)玻璃為基板之感測元件，並將此元件之氧化銦錫導電層藉由導線與金氧半場效電晶體(Metal-Oxide-Semicondcutor Field-Effect Transistor, MOSFET, CD4007UB)之閘極結合，以形成一分離結構之延伸式閘極場效電晶體(Separate Structure of Extended-Gate Field-Effect Transistor, SEGFET)；同時於此ITO與AlN/ITO基板表面設計接觸窗口製備一層對氯離子具有選擇性之薄膜，以形成氯離子感測器。此研究利用恆壓恆流(Constant Voltage Constant Current, CVCC)電路結合氯離子感測器進行各項特性分析及量測，並以陣列型式形成六通道讀出電路，進行元件效能量測與分析以比較兩種不同基板的優劣性。實驗證明兩種基板皆適用於氯離子感測，且線性度表現良好。
實驗結果顯示本文研製之氯離子感測器於NaCl待測溶液濃度pCl=1~5之範圍，可獲得電壓感測度與線性度分別為ITO/Glass: 51.8mV/pCl、98%與AlN/ITO: 54.3mV/pCl、97%。而於1000ppm之氯離子標準溶液實驗8小時可獲得之時漂變化量分別為ITO/Glass: 0.915mV/hr；AlN/ITO: 18mV/hr。整體平均遲滯量：ITO/Glass: 11.65mV; AlN/ITO: 8mV。本研究之氯離子感測元件檢測量範圍廣、線性度高且再現性佳，且因分離式元件架構，可製作成一低成本、可拋棄式氯離子感測器，適合應用於水質監測系統。

關鍵字

銦錫氧化物 ； 氮化鋁 ； 分離結構之延伸式閘極場效電晶體 ； 氯離子選擇薄膜 ； 恆壓恆流電路

並列摘要

This study presents a chloride ion sensor which was prepared by using separate structure of extended gate field effect transistor (SEGFET). Two substrates were employed: indium tin oxide on slide glass (ITO/Glass) and aluminum nitride deposited on ITO/Glass (AlN/ITO/Glass). Membrane sensitive to chloride ions was deposited onto windows of these substrates. Afterwards, the ITO layer in these sensor heads were connected to commercially available MOSFET transistors (CD4007UB) to complete two kinds of SEGFET chloride ion sensors.
The characterization of SEGFET chloride ion sensors utilized a constant voltage constant current (CVCC) interface circuitry. The sensitivity of sensors was evaluated using sodium chloride (NaCl) solutions with concentration from pCl 1 to pCl 5. Experiments on the sensitivity yielded: 51.8 mV/pCl of 98% linearity for the chloride ion sensor on ITO/Glass; and 54.3 mV/pCl of 97% linearity for the chloride ion sensor on AlN/ITO/Glass. The stability of sensors was also tested. After 8 hours in 1000 ppm NaCl solution, the time drift of sensors was determined: 0.915 mV/hr for the chloride ion sensor on ITO/Glass; and 18 mV/hr for the chloride ion sensor on AlN/ITO/Glass. Furthermore, the average hysteresis of sensors: around 11.65 mV for the chloride ion sensor on ITO/Glass; and around 8 mV for the chloride ion sensor on AlN/ITO/Glass. Based on experimental results, the SEGFET chloride ion sensors using ITO/Glass and AlN/ITO/Glass both exhibited wide range of pCl detection, good linearity, stable performance and acceptable reproducibility.
With the availability of chloride ion sensors suitable for pCl measurements of water, the low cost structure of SEGFET, this study successfully showed that a portable chloride ion measurement system for real-time water monitoring application is very possible.

並列關鍵字

Indium Tin Oxide ITO ； Aluminum Nitride AlN ； Separate Structure of Extended Gate Field Effect Transistor SEGFET ； chloride ion selective membrane ； Constant Voltage Constant Current CVCC