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(Ta-Yu Hung)

指導教授 ： 鍾文耀

中原大學/工學院/電子工程研究所/碩士(2009年)

https://doi.org/10.6840/CYCU.2009.00910

摘要

由於近年來國民對於保健、養身與環境保護等生活健康議題日趨重視，其與自來水、飲用水等生活必需品習習相關，所以對於水資源中各式離子的即時監測儼然成為近年來熱門研究的課題。
本論文係製備以氧化銦錫(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透過導線與MOSFET(CD4007UB)之閘極結合，以形成一分離結構之延伸式閘極離子感測場效電晶體(Separate Structure of Extended-Gate Field-Effect Transistor, SEGFET)；同時於此ITO與AlN/ITO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，而其氯離子選擇膜成分由PVC、DOS、ETH9033、THF依特定比例調和而成，其中ETH9033為一可與氯離子反應之離子選擇物質(Ionophores)。之後利用半導體參數分析儀(Agilent B1500A Semiconductor Device Analyzer)對此感測元件進行各項特性分析及量測，此外亦利用恆壓恆流(Constant Voltage Constant Current, CVCC)電路應用於氯離子感測器以深入分析更多重要參數。有鑑於即時水質監測之目標，吾人設計一適合此氯離子感測元件之讀出電路，並朝可攜式、積體化之方向發展。
實驗結果顯示使用本研究之ITO Glass與AlN/ITO Glass結構作為氯離子感測元件，於NaCl待測溶液濃度pCl=1～5中，可獲得電壓感測度與線性度；ITO/Glass：51.8mV/pCl、98%；AlN/ITO：54.3mV/pCl、97%。時漂效應方面則於1000ppm之氯離子標準溶液內實驗8小時可獲得時漂變化量；ITO/Glass：0.915mV/ hr；AlN/ITO：18mV/ hr。而遲滯效應方面，在各種不同濃度之NaCl溶液中反覆地進行量測，順序如下：pCl3、pCl2、pCl1、pCl2、pCl3、pCl4、pCl5、pCl4、pCl3，每20分鐘改變一次濃度，可知在pCl3時之遲滯效應：ITO/Glass：15mV；AlN/ITO：16mV。
由上述結果發現，本研究使用氯離子選擇膜滴於ITO Glass與AlN/ITO之感測元件範圍廣、線性度佳且再現性佳，適合應用於水質監測系統。而且因為使用分離式元件架構，故可製作成一低成本可拋棄式離子感測場效電晶體，應用於氯離子檢測。而本研究之氯離子恆壓恆流讀出電路晶片下線所採用的製程是台灣積體電路公司提供之0.35um Mixed-Signal 2P4M Polycide製程。

關鍵字

讀出晶片 ； 水質監測 ； 半導體參數分析儀 ； 再現性 ； 恆壓恆流電路 ； 遲滯效應 ； 時漂效應 ； 離子選擇物質 ； 氧化銦錫 ； 氮化鋁 ； 延伸式閘極場效電晶體 ； 氯離子感測器 ； 分離結構之延伸式閘極場效電晶體

並列摘要

From recent years, people are becoming more and more conscious on health and environment protection issues. An instance in the field of research is real-time monitoring of water quality for safe human consumption having continued impact and significance.
This study presents ion sensors that define chlorine concentration (pCl) of aqueous solutions. Chloride ion (Cl-) sensors were prepared using separate extended gate field effect transistor (SEGFET) structure. 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. Such membrane was synthesized from PVC polymer, DOS plasticizer, ETH9033 ionophore, and THF additive. Afterwards, the ITO part in these sensor heads (PVC-DOS-ETH9033-THF/ITO/Glass, PVC-DOS-ETH9033-THF/AlN/ITO/Glass) 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 semiconductor device analyzer (Agilent B1500A) and 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 V/hr for the chloride ion sensor on ITO/Glass; and 0.018 V/hr for the chloride ion sensor on AlN/ITO/Glass. Furthermore, the hysteresis of sensors was verified using NaCl solution with pCl level altered every 20 minutes in the direction of pCl 3, pCl 2, pCl 1, pCl 2, to pCl 3, pCl 4, pCl 5, pCl 4, and to pCl 3 again. The hysteresis of sensors measured at pCl 3: around 15 mV for the chloride ion sensor on ITO/Glass; and around 16 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.
The CVCC interface of SEGFET chloride ion sensors was fabricated in integrated circuit using TSMC 2P4M 0.35 micron CMOS technology. The design, simulations and tests of this chip are also reported in this study.
With the availability of chloride ion sensors suitable for pCl measurements of water, the low cost structure of SEGFET, together with the readout chip implementation, 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

Readout chip ； Water monitoring. ； Semiconductor device analyzer ； Reproducibility ； Constant Voltage Constant Current (CVCC) ； Hysteresis ； Drift ； Ionophore ； Indium Tin Oxide (ITO) ； EGFET ； Separate Extended Gate Field Effect Transistor ； Aluminum Nitride(AlN) ； Chloride ion sensor

參考文獻

[4]劉康義, "離子感測場效電晶體巨集行為模型開發與感測陣列訊號處理電路設計", 中原大學電子工程學系碩士論文, 2004.

[33]劉泰村, "應用於電子舌系統之電位式感測電路設計", 中原大學電子工程學系碩士論文, 2008.

[50]何福順, "ISFET酸鹼感測器陣列補償校正與系統設計", 中原大學電子工程學系碩士論文, 2005.

[1]蔡侑霖, "晶圓層次之離子感測器效能分析與流體注入式分析", 中原大學電子工程學系碩士論文, 2007.

[2]P. Bergveld, "Development of an Ion-Sensitive Solid-State Device for Neurophysiological Measurements", Biomedical Engineering, IEEE Transactions on, vol. BME-17, pp. 70-71, 1970.