利用具有奈米孔徑的模板來製備低維度奈米材料是一個成本低而具有潛力的方法，且不需要利用昂貴地微影製程設備，即可成功地製備奈米陣列於基板上。而模板法中又以陽極氧化鋁 (anodic aluminum oxide；AAO) 模板，為較引人注目的材料，因為陽極氧化鋁模板為奈米孔洞材料，孔洞規則性佳以及孔洞密度高等優點，並可藉由改變製程參數改變孔洞大小和孔洞間距。 在此研究中，是利用電子束蒸鍍機台(electron-beam evaporator)，透過陽極氧化鋁模板，成功地製備出具有週期性排列的銀奈米結構於玻璃基板上，而此陽極氧化鋁模板，則是經由將高純度鋁片置於 0.3 M 的草酸電解液中，將反應溫度控制在 0－3 oC 範圍內，並施加固定外加電壓為 40 V的陽極處理環境下，經過兩次陽極處理 (two-step anodization) 後，則可獲得蒸鍍用的模板，另外並可藉由調整二次陽極處理的時間來調控陽極氧化鋁模板的長寬比 (aspect ratio)，以及控制擴大孔洞 (pore-widening) 的時間，改變其孔洞直徑和孔洞與孔洞之間距。 由於在蒸鍍金屬時，具有孔洞遮蔽效應的因素影響，因此可藉由改變沉積時，銀的蒸鍍厚度，製備出不同形貌的銀奈米結構，如：奈米圓盤狀、奈米半橢圓狀、和奈米圓錐狀等。並利用可見光紫外光光譜儀，觀察其沉積於玻璃基板上之銀奈米結構的長寬比對於表面電漿共振的特性的影響，當銀的奈米結構長寬比從 0.25 增加至 1 時，產生了藍位移的現象，而其表面電漿共振特徵峰則從波長 454 nm 位移至 434 nm。 Nanosize templates are a low-cost and promising approach for deposition of low-dimensional nanomaterials or transfer of nanopatterns onto a substrate without using costly lithography equipments. Among the nanosize templates, anodic aluminum oxide (AAO) membrane is one of the most attractive nanopore materials due to its highly ordered structure, high pore density and tunable pore size. In this study, periodic silver (Ag) nanostructures on glass substrates were fabricated by depositing Ag through AAO templates using an electron-beam evaporator. The AAO membranes were prepared by the two-step anodization electrochemical procedure of aluminum sheet in 0.3 M oxalic acid solution under a constant applied voltage of 40 V, and their aspect ratio and pore size could be well-controlled by adjusting the second anodization time and pore-widening time. Due to the closure effect during the deposition process, various shapes of Ag nanostructures (such as, nano-disks, nano-hemispheres and nano-cones) could be obtained by changing the amount of Ag deposited through the AAO templates. The effect of the aspect ratios on surface plasmon resonance (SPR) properties of Ag nanostructure arrays on the glass substrates were investigated using a UV-visible spectrophotometer. As the aspect ratio increases from 0.25 to 1, the absorption peak position (λSPR) undergoes a blue shift from 454 nm to 434 nm.
