日常生活中，大部份的氣體為無色無味，人類的嗅覺沒辦法準確分辨氣體的種類。當空氣中存在著一些對人體有害的氣體時，假若能以氣體感測器偵測，做適當的處理，則可確保人身安全。金屬氧化物半導體對氣體具備的良好檢測特性，隨著微機電製造技術的成熟，感測晶片能夠微小化，易於整合於攜帶式裝置上，並且能夠大量生產，具備結構簡單、低成本的特點。
本研究將開發一種電阻式半導體氣體感測器，使用三氧化鎢(Tungsten oxide, WO3)作為感測材料，將WO3材料研磨至奈米等級的顆粒尺寸，以點膠的方式附著於感測晶片上，製作出具有高表面積的多孔感測層。並將微加熱器製作於晶片中，量測時能夠由晶片上的加熱器加熱至所需的量測溫度，不須額外提供熱源。最終製作出的感測晶片能夠對低濃度(50-665ppb)的H2S有著優異的響應，並且在H2的重複量測實驗中驗證了感測器的穩定度。
在本篇論文最後，提出複合感測晶片的概念，將八個感測單元製作在一個晶片上，透過操作條件與感測材料的變化組合，量測時便能形成複合式的訊號，希望藉此方法能夠解決電阻式半導體氣體感測器選擇性較低的缺點，使其能有更多的應用。

In daily life, most of the gas is colorless and odorless, and human sense of smell cannot accurately distinguish the type of gas. When there are some gases harmful to the human body in the air, if it can be detected by the gas sensor and properly treated, that is able to ensure personal safety. Metal oxide semiconductors have good detection capabilities for gases. With the maturity of MEMS manufacturing technology, sensing chips can be miniaturized, easy to integrate on portable devices, and be mass-produced. It has the advantages of simple structure and low cost.
This study will develop a semiconductor gas sensor using tungsten oxide (WO3) as the sensing material. Mounted on the sensor chip in a dispensing approach to produce a porous sensing layer having a high surface area. The micro-heater is fabricated in the wafer and can be heated by the heater on the wafer to the desired measurement temperature without additional heat source. The resulting sensor was able to respond well to low concentrations (50-665 ppb) of H2S, and the stability of the sensor was verified in the repeated measurement experiment of H2.
At the end of this paper, the concept of a composite sensing wafer is proposed. The eight sensing units are fabricated on one chip, through the different combinations of operating con-ditions and sensing materials, a composite signal can be formed during the measurement. Hoping this approach can solve the disadvantage of the lower selectivity of the resistive sem-iconductor gas sensor, so that it can have more applications.

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