本研究是利用單晶矽經由電化學陽極氧化蝕刻來製造出多孔矽構造之薄膜，透過這種方法使非直接能隙的單晶矽轉變成直接能隙的多孔矽，試片製作完成後先以紫外燈、光激發光譜儀（ＰＬ）觀察其發光現象與光學性質並使用場發射掃描式電子顯微鏡（ＳＥＭ）對照表面結構，最後以ＩＶ測量電學性質來比較。此新穎且特殊之薄膜材料：具備高體表面積比、高阻抗特性、高絕熱特性以及高介電係數等，可以大幅提升元件及感測系統之測量品質和穩定度，利用多孔隙薄膜高反應性及靈敏度的優點，針對不同的液體甚至氣體及其不同濃度進行測量。試片以銅金屬當背金屬改善電化學蝕刻時矽與銅兩種不同導電性所出現的不均勻現象，增加導電度，再利用金在正面鍍上指叉狀的機構來增加準確性與靈敏度，此金屬與半導體結合成歐姆性質的接面並帶有電阻或電容的功能。最後以微波電漿在表面蝕刻出更多的孔洞，增加表面積進一步提高多孔矽薄膜感測的靈敏度。製作出的多孔矽薄膜感測試片期望不但可以提高使用度，並利用切割方式製作出拋棄式試片供各種檢體去做檢測達到降低成本並且大量生產，未來應用一定會更加的廣泛。
In this study‚ silicon is used for the electrochemical etching to produce porous silicon structure. The porous silicon sample is measured by UV, PL, SEM and I-V. The membrane material has the characteristics of high-surface area ratio, high impedance, high thermal insulation, and with a high dielectric coefficient. These characteristics can be significantly improve the quality and stability of Si-based systems in optical-electronic industry. Meanwhile such a membrane can be used these for the liquid and the gas sensing.
In the study, the sample back surface plated with copper is used to increase the conductivity. The gold plating is used on the front multi-finger to increase the accuracy and sensitivity. Finally microwave plasma etching is adopted to enhance the sensitivity. The results show,the high surface of porous silicon can provide a high sensitivity in the Si-based sensing systems.
