Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA.
Nanotechnology. 2016 Sep 30;27(39):395302. doi: 10.1088/0957-4484/27/39/395302. Epub 2016 Aug 25.
Nanosphere lithography (NSL) has been widely used as an inexpensive method to create periodic arrays of metallic nanoparticles or nanodiscs on substrates. However, most nanodisc arrays derived from a NSL template are restricted to hexagonally-ordered triangular arrays because the metal layer is deposited onto the interstices between the nanospheres. Metallic nanodisc arrays with the same arrangement as the original nanosphere array have been rarely reported. Here, we demonstrate a facile, low-cost method to fabricate large-area hexagonal arrays of metallic nanodiscs using an NSL template combined with a two-step lift-off process. We employ a bi-layer of two dissimilar metals to create a re-entrant sidewall profile to undercut the sacrificial layer and facilitate the final lift-off of the metallic nanodiscs. The quality of the nanodisc pattern and the array periodicity is determined using statistical image analysis and compared to the original nanosphere array in terms of size distribution, surface smoothness, and array pitch. This nanodisc array is used as an etch mask to create a vertically-aligned Si nanowire array. This combined approach is a scalable and inexpensive fabrication method for creating relatively large-area, ordered arrays of various nanostructures.
纳米球光刻（NSL）已被广泛用作在衬底上制造周期性金属纳米粒子或纳米盘阵列的廉价方法。然而，由于金属层沉积在纳米球之间的间隙上，大多数源自 NSL 模板的纳米盘阵列仅限于六边形有序的三角形阵列。具有与原始纳米球阵列相同排列的金属纳米盘阵列很少有报道。在这里，我们展示了一种使用 NSL 模板结合两步剥离工艺制造大面积六边形金属纳米盘阵列的简单、低成本方法。我们采用两层两种不同的金属来创建一个重新进入的侧壁轮廓，以切入牺牲层并促进金属纳米盘的最终剥离。使用统计图像分析来确定纳米盘图案的质量和阵列周期性，并根据尺寸分布、表面平整度和阵列间距与原始纳米球阵列进行比较。该纳米盘阵列用作刻蚀掩模，以制造垂直对齐的硅纳米线阵列。这种组合方法是一种可扩展且低成本的制造方法，可用于制造各种具有相对大面积和有序排列的纳米结构。
