Silicon Nanostructures Formation by V2O5 and HF Stain Etching

Abstract

In this work we report the fabrication of silicon pillar array by a simple chemical etching of silicon in vanadium oxide/fluorhydric acid solution. Different etching parameters including the solution concentration, temperature and orientation of Si substrates and thin metal catalyst film deposition (Pd) on the Si surface were studied. The etched surfaces characterized by Scanning Electron Microscopy are shown below. It has been found that the morphology depends on both etching time and the presence of the catalyst. The attack, on the surfaces with a Palladium deposit, begins by creating circular pores on silicon in which we distinguish the formation of nanopillars of silicon. After several minutes of etching, silicon pillars appear, but the morphology seems strongly conditioned by drying, like in metal assisted etched SiNWs and highly porous silicon. Finally, taking into account the obtained results, a mechamism of the chemical etching is proposed