Nanowires fine tunable fabrication by varying the concentration ratios, the etchant and the plating spices in metal-assisted chemical etching of silicon wafer.

The metal-assisted chemical etching (MACE) was used to synthesis silicon nanowires. The effect of etchant concentration, etching and chemical plating time and doping density on silicon nanowires length were investigated. It is held that the increasing of HF and H۲O۲ concentrations lead to etching rate increment and formation of wire-like structure. The results show that, the appropriate ratio of concentration to form the silicon nanowires obeyed the [HF]/[H۲O۲]  = R equation when R= ۲.۵, ۳ and ۳.۵ and any deviation of these ratio, cause to destruction of wire-like structure. Moreover, the critical etching rates to form the SiNWs are in the range of ۴nm/s to ۵nm/ s.

Keywords:

metal , assisted chemical etching , Silicon nanowires , Etching rate , Concentration ratios