在本研究中，我們透過多步驟貴金屬輔助化學蝕刻法，藉由調控蝕刻溶液的組成比例，以及改變在不同溶液中的浸泡時間，成功的在P-type(001)以及N-type(001)晶面之矽單晶基材上製備出高深寬比以及大面積準直排列之彎曲轉折型矽晶奈米線結構。氣體偵測性能則是透過丙酮、氧氣來驗證不同類型之矽晶氣體感測元件對於氧化性以及還原性氣體之電性趨勢變化以及其作用機制。此外，本研究為提升氣體感測元件之偵測能力，進一步導入酸性橫向蝕刻製程技術，製備出多孔隙彎曲轉折型矽晶奈米線結構，以提高偵測元件之比表面積；並在最佳條件之多孔隙彎曲轉折型矽晶奈米線結構上利用無電鍍銀法披覆銀奈米粒子，藉此來改善氣體偵測性能。銀/多孔隙彎曲轉折型矽單晶奈米線氣體感測元件，和一般常見之一維矽晶奈米結構之氣體感測元件相比，在定電壓下之偵測靈敏度有顯著的提升。 本研究使用一步驟金屬輔助化學蝕刻法，製備出厚度均勻之超薄可撓曲矽單晶基材，再將此基材和前述所開發出之銀/多孔隙彎曲轉折型矽晶奈米線結構進行結合，成功製備出可撓曲銀/多孔隙彎曲轉折型矽晶奈米線氣體感測元件。此元件展現出十分良好之彎曲能力，可分別於曲率半徑為2.5 cm、1.5 cm操作情況下進行氣體偵測。 最後，本研究針對大多數氣體感測元件中常見之恢復時間過長問題提出改善方式，利用金屬輔助化學蝕刻法結合鹼性蝕刻法，在可撓曲基材上，製備矽晶通道結構，並與上述製備之可撓曲銀/多孔隙彎曲轉折型矽晶奈米線結構結合，製備出可撓曲銀/多孔隙彎曲轉折型矽晶奈米線/矽晶通道異質結構氣體感測元件，藉由矽晶通道所提供之額外氣體脫附路徑，來縮短元件之恢復時間，以達到優化元件性能之目的。 ;In this study, the large-area, vertically-aligned single crystalline kinked silicon nanowires array(KSiNWs) was successfully fabricated on P-type(001) and N-type(001) substrate by a multiple steps noble metal assisted chemical etching(MACE)。The gas-sensing performance was evaluated by acetone and oxygen to investigate the detecting trend and mechanism. In order to increase the surface area to volume ratio, we used lateral etching technique to fabricate porous kinked silicon nanowire. In addition, so as to improve the gas-sensing performance, this study developed a electroless Ag deposition process which could uniformly decorate Ag nanoparticles on the porous KSiNWs. The Ag/Porous KSiNWs exhibited better gas–sensing performance than normally Si-based 1D nanostructure gas sensor. The one step noble metal assisted chemical etching method was used to prepare uniform ultra-thin Si substrate. Then, using the process we just mentioned above to fabricate Ag/Porous KSiNWs on ultra-thin Si substrate. The gas-sensing detection could be performed when the radius of curvature was 2.5 cm and 1.5 cm respectively. Finally, this study proposed a way to improve the long recovery time issues which was usually encounter in most of gas sensing devices. We used noble metal-assisted chemical etching to fabricate micro-nanoscale hole structures on flexible Si substrates. Then, using the process we mentioned above to fabricate Ag/Porous KSiNWs on the front side of ultra-thin Si substrate. This structure provided additional path for gas desorption. Therefore, we look forward to shorten recovery time and optimizing the performance of the gas-sensing device.
