Lithography-free fabrication of silicon nanowire and nanohole arrays by metal-assisted chemical etching
1 Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, 215123, People's Republic of China
2 Department of Electrical and Computer Engineering, University of Waterloo, 200 University Avenue, West Waterloo, Ontario, N2L3G1, Canada
Nanoscale Research Letters 2013, 8:155 doi:10.1186/1556-276X-8-155Published: 4 April 2013
We demonstrated a novel, simple, and low-cost method to fabricate silicon nanowire (SiNW) arrays and silicon nanohole (SiNH) arrays based on thin silver (Ag) film dewetting process combined with metal-assisted chemical etching. Ag mesh with holes and semispherical Ag nanoparticles can be prepared by simple thermal annealing of Ag thin film on a silicon substrate. Both the diameter and the distribution of mesh holes as well as the nanoparticles can be manipulated by the film thickness and the annealing temperature. The silicon underneath Ag coverage was etched off with the catalysis of metal in an aqueous solution containing HF and an oxidant, which form silicon nanostructures (either SiNW or SiNH arrays). The morphologies of the corresponding etched SiNW and SiNH arrays matched well with that of Ag holes and nanoparticles. This novel method allows lithography-free fabrication of the SiNW and SiNH arrays with control of the size and distribution.