奈米球鏡微影術及孔洞遮罩微影術製作三維手性超穎材料之研究

Abstract

在此論文中，我將利用低成本的奈米製程技術，製作出大面積的三維手性超穎材料。首先，透過奈米球鏡微影術做出週期的金屬奈米孔洞於光阻上，以作為之後蒸鍍所需的遮罩。再依照孔洞遮罩微影術的概念，傾角斜向蒸鍍金屬及氧化層，成功把金屬層及氧化層相疊後，使其呈螺旋狀的奈米結構，此結構的手性近場會與不同手性的分子產生交互作用，得到在近紅外光波段的新圓二色性光譜，再透過此光譜分辨出分子的手性。 此外，我們也利用時域有限差分法(FDTD)來模擬計算我們的結構特性，和實驗相互驗證。最後，我們相信此技術，在未來的生化工業上，會有絕佳的應用。

In this study, we have demonstrated a cost effective nanofabrication method to fabricate three-dimensional (3D) chiral metamaterial arrays covering a large area. First, Nanospherical-Lens Lithography (NLL) is employed to fabricate periodic metal nanohole arrays on top of photoresist film. This sample configuration is ideal for the following angled metal or dielectric material evaporation, whose concept is very similar to Hole-Mask Lithography. Metal and dielectric materials are deposited sequentially and nanodisks stacked up in a spiral manor are successfully demonstrated. The fabricated 3D nanostructures exhibit optical chirality in the near-infrared and interact differently for chiral molecules with different handedness. The measured circular dichroism (CD) offers the possibility to distinguish chemical molecules with different handedness. Finite-difference time-domain method is also performed to confirm our experimental observation. We believe the proposed methods will very useful in future biological or chemical application.