Plasmonic tooth-multilayer structure with high enhancement field for surface enhanced Raman spectroscopy
Plasmonic tooth-multilayer structure with high enhancement field for surface enhanced Raman spectroscopy
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DOI：
10.1088/1361-6528/aa5ebf
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发表时间：
2017-03-24
期刊：
影响因子：
3.5
通讯作者：
Delaunay, Jean-Jacques
中科院分区：
文献类型：
--
作者：
Huang, Li-Chung;Wang, Zhiyu;Delaunay, Jean-Jacques
在表面增强拉曼散射（Sers）中看到的显著增强在很大程度上依赖于等离子体结构强烈限制光的能力。用于制造等离子体纳米结构的当前技术在其自下而上技术的再现性或其自上而下技术的特征尺寸方面受到限制。在这里，我们提出了一种齿多层结构，可以通过使用物理气相沉积和选择性湿法蚀刻，实现极小的特征尺寸和高再现性。使用离子束溅射在平坦衬底上沉积由两种交替材料组成的多层结构，其厚度可以精确地控制在纳米范围内。随后的选择性湿法蚀刻用于在构成多层的材料之一中形成纳米间隙，其中纳米间隙的深度由湿法蚀刻时间控制。结合这两种技术可以允许纳米间隙尺寸被控制在10 nm以下的长度尺度，从而实现在宽范围内具有共振模式的高增强和可调谐性的牙齿多层结构，这对于Sers应用是理想的。
The significant enhancement seen in surface-enhanced Raman scattering (SERS) heavily relies on the ability of plasmonic structures to strongly confine light. Current techniques used to fabricate plasmonic nanostructures have been limited in their reproducibility for bottom-up techniques or their feature size for top-down techniques. Here, we propose a tooth multilayer structure that can be fabricated by using physical vapor deposition and selective wet etching, achieving extremely small feature sizes and high reproducibility. A multilayer structure composed of two alternating materials whose thicknesses can be controlled accurately in the nanometer range is deposited on a flat substrate using ion-beam sputtering. Subsequent selective wet etching is used to form nanogaps in one of the materials constituting the multilayer, with the depth of the nanogaps being controlled by the wet etching time. Combining both techniques can allow the nanogap dimensions to be controlled at sub 10 nm length scale, thus achieving a tooth multilayer structure with high enhancement and tunability of the resonance mode over a broad range, ideal for SERS applications.