Size and density control of silicon oxide nanowires by rapid thermal annealing and their growth mechanism

Abstract

In this work, we demonstrate a fast approach to grow SiO2 nanowires by rapid thermal annealing (RTA). The material characteristics of SiO2 nanowires are investigated by field emission scanning electron microscopy, high-resolution transmission electron microscopy (HRTEM), high-angle annular dark-field (HAADF) imaging, electron energy loss spectroscopy (EELS), and energy-filtered TEM (EFTEM). The HAADF images show that the wire tip is predominantly composed of Pt with brighter contrast, while the elemental mappings in EFTEM and EELS spectra reveal that the wire consists of Si and O elements. The SiO2 nanowires are amorphous with featureless contrast in HRTEM images after RTA at 900°C. Furthermore, the nanowire length and diameter are found to be dependent on the initial Pt film thickness. It is suggested that a high SiO2 growth rate of >1 μm/min can be achieved by RTA, showing a promising way to enable large-area fabrication of nanowires.