High performance surface-enhanced Raman scattering substrates of Si-based Au film developed by focused ion beam nanofabrication.
High performance surface-enhanced Raman scattering substrates of Si-based Au film developed by focused ion beam nanofabrication.
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聚焦离子束纳米加工开发的硅基金薄膜高性能表面增强拉曼散射基底
DOI：
10.1186/1556-276x-7-399
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发表时间：
2012-07-17
影响因子：
--
通讯作者：
Xu X
中科院分区：
文献类型：
--
作者：
Gao T;Xu Z;Fang F;Gao W;Zhang Q;Xu X
利用聚焦离子束直写技术（fidw）在Si衬底上刻制纳米结构，并对衬底上的金膜进行精确热蒸发，提出了一种灵活高效的SERS衬底开发新方法。通过优化工艺参数和金膜厚度，系统地研究了SERS对衬底的影响。结果表明，较小的停留时间可以提高加工精度，获得较小的纳米间隙。在10−6mol/L罗丹明6g溶液中考察了底物的拉曼增强性能。结果表明，在Si衬底上包覆约15nm厚的金膜后，具有15nm间距的椭圆型纳米结构的性能得到了显著提高，但随着金膜厚度的增加，其性能出现了明显的下降，这很可能是由于纳米结构的椭圆尖端和间距等形貌发生了变化。为了有效避免金膜沉积后的形貌变化，提出了硅基fidw纳米结构的优化设计。此外，当金膜小于15nm时，由于衬底上残留的金很少，也发现了类似的现象。本文提出的方法对于高性能SERS基板的开发具有很大的潜力，可以进一步减小热点之间的间距。
A novel method with high flexibility and efficiency for developing SERS substrates is proposed by patterning nanostructures on Si substrates using focused ion beam direct writing (FIBDW) technology following with precise thermal evaporation of gold film on the substrate. The effect of SERS on the substrate was systematically investigated by optimizing the processing parameters and the gold film thickness. The results proved that small dwell time could improve the machining accuracy and obtain smaller nanogap. The Raman-enhanced performance of the substrate was investigated with 10−6mol/L Rhodamine 6 G solution. It was indicated that the elliptic nanostructures with 15-nm spacing on Si substrates, coated with approximately 15-nm thick gold film, have exhibited a high-enhanced performance, but dramatic performance degradation was found as the gold film thickness further increased, which most probably resulted from changes of the nanostructures’ morphology such as elliptical tip and spacing. To avoid the morphological changes effectively after depositing gold film, optimization design of the nanostructures for FIBDW on Si substrates was proposed. Besides, a similar phenomenon was found when the gold film was less than 15nm because there was little gold remaining on the substrate. The method proposed in this paper shows a great potential for the higher performance SERS substrates development, which can further reduce the spacing between hot spots.