以互補式金氧半導體積體電路過取樣三角積分轉換器應用於生物感測器設計及實現

The Implantation and Design of CMOS Integrated Circuit Oversampling ΣΔ Converter for Biosensor System

陳鐘沅(Chung-Yuan Chen)

指導教授 ： 孫台平

國立暨南國際大學/科技學院/電機工程學系/博士(2010年)

https://doi.org/10.6837/NCNU.2010.00186

摘要

本論文以互補式金氧半導體設計並實現應用於生物感測器之過取樣三角積分轉換器，該過取樣三角積分轉換器可直接將氫離子濃度轉換至數字形式而不需要傳統之類比信號處理電路。延伸式閘極場效應晶體為本論文使用之感測元件，該元件可分為兩個部分：一是包含感測薄膜之感測端，另一為金屬氧化物場效電晶體。本論文以濺鍍機台將二氧化錫濺射於鍍銦錫氧化物玻璃上，並以二氧化錫/鍍銦錫氧化物玻璃作為延伸式閘極場效應晶體之感測端。
利用延伸式閘極場效應晶體製作運算放大器，並以該延伸式閘極場效應晶體之運算放大器配開關電容及三角積分轉換器技術實現互補式金氧半導體直接氫離子對數位轉換器。該晶片以0.18微米之互補式金氧半導體1P6M製程製作，該電路所需使用之電源電壓為1.8伏特，一般取樣頻率設為6.25MHz，並於氫離子濃度2及氫離子濃度10之緩衝液下，該轉換器之增益誤差在正負2個百分比內，並於該偵測濃度下，最低可檢出之氫離子值可達到正負0.02pH。

關鍵字

互補式金氧半導體 ； 二氧化錫 ； 鍍銦錫氧化物 ； 延伸式閘極場效應晶體 ； 過取樣 ； 三角積分轉換器 ； 開關電容

並列摘要

A CMOS oversampling sigma-delta converter has been developed for continuous monitoring of H+-ion concentrations. The sigma-delta converter transforms the H+-ion concentrations into digital format directly without any conventional analog signal processing circuit. Extended gate field effect transistor is separated into two parts. One is the sensing structure containing the sensitive membrane and the other is the metal oxide field effect transistor. The SnO2/ITO glass, fabricated by sputtering SnO2 on the conductive ITO glass, was used as a pH-sensitive membrane of extended gate field effect transistor. The CMOS oversampling sigma-delta converter, constructed using extended gate field effect transistor operational amplifier to realize switched-capacitor sigma-delta converter, converted the H+-ion concentration into digital form. This chip, fabricated in a 0.18-um CMOS 1P6M process, operated at a 1.8V supply voltage and normal sampling rate of 6.25MHz. The gain errors of the converter in the H+-ion concentration range between pH 2 and pH 10 is less than 2%, and the minimum detectable pH value can reach as small as ±0.02pH.

並列關鍵字

CMOS ； SnO2 ； ITO ； Extended Gate Field Effect Transistor ； Oversampling ； Sigma-Delta ； Switched-Capacitor

參考文獻

[1] J. N. Babanezhad, “A rail-to-rail CMOS Op amp.” IEEE Journal of Solid-Slate Circuit, vol. 23, pp. 1414-1417, 1988.

[2] W. C. S. Wu, “Digital-compatible high-performance operational amplifier with rail-to-rail input and output ranges,” IEEE Journal of Solid-State Circuits, vol. 29, no. 1, Jan. 1994.

[3] J. H. Huijsing and D. Linebarger, “Low-voltage operational amplifier with rail-to-rail input and output ranges,” IEEE Journal of Solid-State Circuits, vol. SC-20, pp. 1144-1150, Dec. 1985.

[4] R. Hogervorst et al., “CMOS low-voltage operational amplifiers with constant-gm rail-to-rail input stage,” Analog Integrated Circuit Signal Processing, vol. 5, no. 2, pp. 135-146, Mar. 1994.

[5] D. M. Montecelli, “A quad CMOS single-supply op amp with rail-to-rail output swing,” IEEE Journal of Solid-Stare Circuits, vol. SC-21, pp. 1026-1034, Dec. 1986.