Control of the Morphology of Si Nanostructure Using Single-Step Metal Assisted Etching Method

Abstract

The morphological changes of etched Si surfaces on the concentration of AgNO3 using single-step metal assisted etching and their reflectance were investigated. We used aqueous mixture solution containing silver nitrate (AgNO3) and hydrofluoric acid (HF) as single-step metal assisted etching solution. With changing concentration of silver ions in the etching solution, three types of Si surface morphologies (“nanowire”, “wall”, “polished”) were prepared. Then, phase diagram is developed for these morphologies obtained as a function of AgNO3 concentration and resistivity of silicon substrates. The measurement of reflectance for etched surface indicates that the nanowire is the lowest reflectance of three types of morphologies.