Department of Micro- and Nanotechnology, Technical University of Denmark (DTU) , Anker Engelunds Vej 1, Kongens Lyngby 2800, Denmark.
ACS Appl Mater Interfaces. 2016 Jun 22;8(24):15668-75. doi: 10.1021/acsami.6b05431. Epub 2016 Jun 9.
We report a novel nanofabrication process via block copolymer lithography using solvent vapor annealing. The nanolithography process is facile and scalable, enabling fabrication of highly ordered periodic patterns over entire wafers as substrates for surface-enhanced Raman spectroscopy (SERS). Direct silicon etching with high aspect ratio templated by the block copolymer mask is realized without any intermediate layer or external precursors. Uniquely, an atomic layer deposition (ALD)-assisted method is introduced to allow reversing of the morphology relative to the initial pattern. As a result, highly ordered silicon nanopillar arrays are fabricated with controlled aspect ratios. After metallization, the resulting nanopillar arrays are suitable for SERS applications. These structures readily exhibit an average SERS enhancement factor of above 10(8), SERS uniformities of 8.5% relative standard deviation across 4 cm, and 6.5% relative standard deviation over 5 × 5 mm(2) surface area, as well as a very low SERS background. The as-prepared SERS substrate, with a good enhancement and large-area uniformity, is promising for practical SERS sensing applications.
我们报告了一种通过使用溶剂蒸气退火的嵌段共聚物光刻技术的新型纳米制造工艺。该纳米光刻工艺简单且可扩展，可在整个晶圆衬底上制造高度有序的周期性图案，用于表面增强拉曼光谱（SERS）。通过嵌段共聚物掩模进行的直接硅蚀刻具有高纵横比，而无需任何中间层或外部前体。独特的是，引入了原子层沉积（ALD）辅助方法，以允许相对于初始图案反转形态。结果，制造出具有可控纵横比的高度有序的硅纳米柱阵列。经过金属化后，得到的纳米柱阵列适用于 SERS 应用。这些结构很容易表现出平均 SERS 增强因子大于 10（8），在 4 cm 范围内的 SERS 均匀性为 8.5%相对标准偏差，在 5×5 mm（2）表面积范围内的均匀性为 6.5%相对标准偏差，以及非常低的 SERS 背景。所制备的 SERS 衬底具有良好的增强效果和大面积均匀性，有望用于实际的 SERS 传感应用。
