Large-area fabrication of silicon nanostructures by templated nanoparticle arrays

An improved nanoscale processing technique by using polystyrene (PS) nanoparticles as a mask is successfully implemented to produce vertically aligned silicon nanowire (SiNW) arrays. Lithographic microstructures with different shapes and opening sizes were applied to determine the fabrication area followed by deposition of a PSS/ PDDA/PSS layer. Therefore, most of the substrate areas were covered and a large-range order of PS nanoparticles can be acquired by detailed investigation of spin-coating parameters and surface properties. Afterwards, the particle size was modulated resulting in feature diameters ranging from 459 +/- 9 nm down to 248 +/- 11 nm. Using this as a mask for inductively coupled plasma (ICP) cryogenic dry etching, a feature-size variation of high-density SiNWs from 225 +/- 18 nm to 146 +/- 7 nm can be achieved. Finally, a method with simple patterning steps has been developed and tested on more than 100 samples emerging as an alternative method for reliable nanostructure realization.