Patterned growth of silicon oxide nanowires from iron ion implanted SiO2 substrates

We demonstrate experimentally a simple and efficient approach for silicon oxide nanowire growth, by implanting Fe+ ions into thermally grown SiO2 layers on Si wafers and subsequently annealing in argon and hydrogen to nucleate the nanowires. We study the effect of implantation dose and energy, growth temperature, H-2 gas flow, and growth time on the silicon oxide nanowire growth. We find that sufficiently high implant dose, high growth temperature, and the presence of H-2 gas flow are crucial parameters for silicon oxide nanowire growth. We also demonstrate the patterned growth of silicon oxide nanowires in localized areas by lithographic patterning and etching of the implanted SiO2 substrates before growth. We propose a simple physical model to explain the growth results. This works opens up the possibility of growing silicon oxide nanowires directly from solid substrates, controlling the location of nanowires at the submicron scale, and integrating them into nonplanar three-dimensional nanoscale device structures.