Microsystems Engineering Centre, Institute of Sensors, Signals and Systems, Heriot-Watt University, Edinburgh, United Kingdom.
Nanotechnology. 2019 Jan 4;30(1):015302. doi: 10.1088/1361-6528/aae795. Epub 2018 Oct 30.
In this work we present a general method for the selective synthesis by photolithography of localised nanostructures in planar geometries. The methodology relies on the previous concept of photo-patternable metallic nanoparticle (NP)/polymer nanocomposites, which can provide a range of NP sizes, polydispersity and densities. First, a photoresist containing metallic ions is patterned by photolithography. Silver NPs are synthesised in situ after the exposure and development of the patterned thin film via the thermal-induced reduction of ions embedded in its structure. Gentle plasma ashing is used to selectively remove the polymer, which leaves NPs on the patterned areas. These NPs are used as seeds for subsequent processes. In order to demonstrate the flexibility of the method, its use to selectively produce localised nanostructures through different processes is shown here. Following a top-down approach, high aspect-ratio silicon nanograss has been produced by reactive ion etching and masking by the NPs. In a bottom-up approach, 280 nm copper clusters have been selectively grown in arrays. This method can be easily extrapolated to other metals and it provides a quick way to selectively generate hierarchical nanostructures in large planar areas that can be used for different applications, such as the fabrication of nanostructured sensor arrays.
在这项工作中，我们提出了一种通过光刻选择性合成平面结构中局部纳米结构的通用方法。该方法依赖于先前提出的光可图案化金属纳米粒子（NP）/聚合物纳米复合材料的概念，该概念可以提供一系列 NP 尺寸、多分散性和密度。首先，通过光刻对含有金属离子的光致抗蚀剂进行图案化。在曝光和显影图案化薄膜后，通过嵌入其结构中的离子的热诱导还原原位合成银 NPs。使用温和的等离子体灰化选择性地去除聚合物，从而在图案化区域留下 NPs。这些 NPs 可用作后续过程的种子。为了展示该方法的灵活性，本文展示了其通过不同的工艺选择性地制备局部纳米结构的用途。通过自上而下的方法，通过 NPs 进行反应离子刻蚀和掩蔽来制备高纵横比的硅纳米草。通过自下而上的方法，在阵列中选择性地生长了 280nm 的铜簇。这种方法可以很容易地推广到其他金属，并为在大平面区域中快速选择性地生成分层纳米结构提供了一种方法，这些结构可用于各种应用，例如制造纳米结构传感器阵列。
