Morphology Transformation of Au Nanoparticles for Vertically Aligned Si Nanowire Arrays

Abstract

The controllable vertically aligned Si nanowire (SiNW) arrays were explored by morphology transformation of Au nanoparticles (AuNPs) from Au film during annealing at different annealing temperatures. The epitaxial growth of SiNW scan be achieved using SiCl4 as the Si precursor in chemical vapor deposition (CVD) via a vapor-liquid-solid (VLS) growth mechanism. The diameter and density of the SiNWs can be controlled by regulating the annealing temperatures, which are related with migration kinetics of Au atoms, during the formation of AuNPs. During the annealing process, uniform AuNPs are formed by Ostwald ripening and gold silicide is produced by diffusing Si atoms from Si(111) wafer into liquid-phase AuNPs at high annealing temperature, leading to uniform diameter and decreasing density of the SiNW.