Role of Chromium Intermediate Thin-Film on the Growth of Silicon Oxide (SiO_x) Nanowires

Abstract

In the present work, one-dimensional nanostructures of silicon oxide (SiO x ) have been synthesized by thermal annealing method with and without chromium thin film on silicon substrate. The synthesis was carried out at different process temperatures ranging from 1000°C to 1100°C by using gold/chromium (Au/Cr) catalysts stack layer on the Si substrate in nitrogen (N 2 ) ambience. The as-synthesized SiO x nanostructures have tetragonal rutile structure and show polycrystalline nature. The SEM images reveal wire-like nanostructures on the substrate with and without chromium thin film. Under the catalytic reaction of the gold/chromium metal, the density of SiO x nanowires is enhanced, since the Cr layer serves as a diffusion barrier for the diffusion of the gold downwards into the Si substrate. The vapor-liquid solid (VLS) growth mechanism is found to be dominant in the growth of SiO x nanowires. Furthermore, X-Ray diffraction microscopy (XRD) and Photoluminescence spectroscopy (PL) analysis conclude the defect free growth of the SiO x nanowires on gold/chrome/silicon substrate.