Stress-driven formation of Si nanowires

Abstract

We present an alternate mechanism for the growth of Si nanowires directly from a silicon substrate, without the use of a metal catalyst, silicon vapor or chemical vapor deposition (CVD) gasses. Since the silicon wires grow directly from the silicon substrate, they do not need to be manipulated or aligned for subsequent applications. Wires in the 20–50 nm diameter range with lengths over 80μm can be easily grown by this technique. The critical parameters in the growth of these nanowires are the surface treatment and the carrier gas used. A model is proposed involving stress-driven wire growth, which is enhanced by surface Si atom diffusion due to the presence of hydrogen gas.