Rapidly fabricating a large area nanotip microstructure for high-sensitivity SERS applications

Jing Ma; Wen Liu; Zhe Ma; Peishuai Song; Yongqiang Zhao; Fuhua Yang; Xiaodong Wang

doi:10.1039/c9nr05168f

Rapidly fabricating a large area nanotip microstructure for high-sensitivity SERS applications

Nanoscale. 2019 Nov 14;11(42):20194-20198. doi: 10.1039/c9nr05168f. Epub 2019 Oct 16.

Authors

Jing Ma¹, Wen Liu², Zhe Ma¹, Peishuai Song³, Yongqiang Zhao¹, Fuhua Yang⁴, Xiaodong Wang⁵

Affiliations

¹ Engineering Research Center for Semiconductor Integrated Technology, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China. xdwang@semi.ac.cn and Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
² Engineering Research Center for Semiconductor Integrated Technology, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China. xdwang@semi.ac.cn.
³ Engineering Research Center for Semiconductor Integrated Technology, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China. xdwang@semi.ac.cn and School of microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China.
⁴ Engineering Research Center for Semiconductor Integrated Technology, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China. xdwang@semi.ac.cn and State Key Laboratory for Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China.
⁵ Engineering Research Center for Semiconductor Integrated Technology, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China. xdwang@semi.ac.cn and Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China and School of microelectronics, University of Chinese Academy of Sciences, Beijing 100049, China and Beijing Academy of Quantum Information Science, Beijing 100193, China and Beijing Engineering Research Center of Semiconductor Micro-Nano Integrated Technology, Beijing 100083, China.

PMID: 31617548
DOI: 10.1039/c9nr05168f

Abstract

Here, we propose a novel nanotip microstructure which can be easily fabricated through a simply Reactive Ion Etching (RIE) process combined with anodic aluminum oxide (AAO) membranes. When combined with Ag coating and annealing on the surface of micro-sized nanotip arrays, the as-formed Ag-nanoparticles (Ag-NPs)/Si-nanotip hybrid structure exhibited a significantly high enhancement factor and highly sensitive surface enhanced Raman scattering (SERS) for rhodamine 6G molecules. The nanotip microstructure showed a sharp curvature with an apex diameter which significantly affected the SERS results. The Ag-NPs/Si-nanotip hybrid structure verified a very prominent "hot spot" effect that exists around the nanotip structures, which contributed mainly to an enhanced SERS signal with an enhancement factor (EF) of 1.6 × 10⁶. Moreover, the Ag-NPs/Si-nanotip hybrid structure demonstrated superior sensitivity, with obvious featured Raman peaks even when the concentration was as low as 10^-10 M. Our work demonstrated a feasible way to prepare a novel nanotip microstructure with a highly localized surface plasmon resonance response which could be feasibly applied for highly sensitive and reproducible SERS applications.