金屬氧化物半導體式氣體感測器具有成本低、壽命長、可微小化、可大量生產、易整合於 Si 製程等特色 與優點，故受到相當多的注目。常見的金屬氧化物半導體式氣體感測器形式為二維感測器由微加熱器所提 供熱能，因加熱與感測電極同一道製程設計，造成中間較低溫外圍較高溫狀況，進而溫度分佈不均產生， 所消耗功率也大。而這次製作的三維結構是將加熱與感測電極分開，且優化加熱電極的圖形，這樣有助於 加熱的均勻與功率的提升。

Metal oxide semiconductor gas sensors have attracted a lot of attention because of their low cost, long life, miniaturization, mass production, and easy integration into Si processes. A common metal oxide semiconductor gas sensor is in the form of a two-dimensional sensor provided by a micro-heater. The heating and sensing electrodes are designed in the same process, resulting in a relatively low temperature peripheral temperature and a temperature distribution. Both are generated and consume a lot of power. The three-dimensional structure produced this time is to separate the heating from the sensing electrode and optimize the pattern of the heating electrode, which contributes to the uniformity of heating and the improvement of power.