A novel fabrication technique for high-aspect-ratio nanopillar arrays for SERS application
Tianli Duan, Chenjie Gu, D. S. Ang, Kang Xu, Zhi‐Hong Liu
Abstract
gas flow during ICP etching, we could achieve nanopillar arrays with sub-30 nm diameter, over 20 aspect ratio, and steep sidewall without collapse. The proposed technique may help break the limit of traditional nanopillar array fabrication, and be applied in many areas, such as Surface-Enhanced Raman Scattering (SERS). A series of SERS simulations performed on nanopillar arrays fabricated by this technique show an obvious Raman spectrum intensity enhancement. This enhancement becomes more obvious when the diameter of the nanopillar becomes smaller and the aspect ratio becomes higher, which may be explained by a high light absorption, the lightning-rod effect, and a greater number of free electrons available at the surface due to the higher density of the surface state.