A MEMS-based Benzene Gas Sensor with WO3 Sensing Layer and Integrated Micro-hotplate

整合氧化鎢感測層與加熱裝置之微型苯氣體感測器

柯明村(Ming-Tsun Ke) ； 江哲銘(Che-Ming Chiang) ； 李佳言(Chia-Yen Lee)

《先進工程學刊》 4卷2期 (2009/04) Pp. 119-125

https://doi.org/10.29948/JAE.200904.0004

摘要

本文乃製作一以微機電技術為基礎之苯氣體感測器，其中以石英材料作為基材，並以白金製作指叉電極與微加熱器，且透過沉積氧化鎢薄膜做為氣體感測層。當環境空氣中帶有苯氣體時，會於加熱之氧化鎢感測層表面產生氧化反應，進而改變氧化鎢薄膜之導電特性，故可經白金指叉電極量測其阻值變化量。而苯氣體濃度可經所量測之阻值推算而得。本文之氧化鎢薄膜可由已最佳化之濺鍍參數進行沉積而得，並且當感測器之工作溫度於300℃時可獲得最佳之感測特性。由實驗數據顯示，本文之感測器不僅具有高靈敏度之特性(9.86% ppm^(-1))，更擁有快速的反應時間(40 s)與回復時間(240 s)。

關鍵字

苯 ； 氣體感測器 ； 微加熱器 ； 微機電系統 ； 氧化鎢薄膜

並列摘要

This study develops a MEMS-based benzene gas sensor consisting of a quartz substrate, a thin-film WO3 sensing layer, an integrated Pt micro-hotplate, and Pt interdigitated electrodes (IDEs). When benzene is present in the atmosphere, oxidation occurs on the heated WO3 sensing layer. This causes a change in the electrical conductivity of the WO3 film, and hence changes the resistance between the IDEs. The benzene concentration is then computed from the change in the measured resistance. A specific orientation of the WO3 layer is obtained by optimizing the sputtering process parameters. It is found that the better sensitivity of the gas sensor is at a working temperature of 300℃. At the working temperature, the experimental results show that the sensor has a high degree of sensitivity (9.86 % ppm^(-1)), a rapid response time (40 s), and a quick recovery time (240 s).

並列關鍵字

benzene ； gas sensor ； micro-hotplate ； MEMS ； WO3 thin film