Porous silicon templates prepared by Cu-assisted chemical etching

• Microstructured template of silicon was successfully fabricated.
• Cu as a low-cost metal was utilized to catalyze the chemical etching.

Porous silicon templates have been prepared by the metal-assisted chemical etching approach with optimized (HF/H2O2) solutions and Cu nanoparticles as the catalyst agents. The effects of metallization time and the concentration of Cu ions on the surface density of Cu nanoparticles on silicon templates have been studied. Besides, the effects of illumination and the composition of etching solution on the morphologies of the obtained nanopores have been investigated. It is found that uniform, isolated and nearly spherical Cu nanoparticles on the silicon surface can be obtained with the metallization processes containing 0.15 mM copper nitrate and 25 ml HF at room temperature for 15 s. Subsequently, the porous silicon templates containing uniform pores with a mean diameter of 1.8 μm have been successfully fabricated under an optimized etching process. The porous silicon templates are believed to be potentially employed for fabrication nanowires (nanotubes) devices compatible with semiconducting industries.