Vapor-liquid-solid growth of 〈110〉 silicon nanowire arrays

The epitaxial growth of 〈110〉 silicon nanowires on (110) Si substrates by the vapor-liquid-solid growth process was investigated using SiCl₄ as the source gas. A high percentage of 〈110〉 nanowires was obtained at high temperatures and reduced SiCl₄ partial pressures. Transmission electron microscopy characterization of the 〈110〉 Si nanowires revealed symmetric V-shaped {111} facets at the tip and large {111} facets on the sidewalls of the nanowires. The symmetric {111} tip faceting was explained as arising from low catalyst supersaturation during growth which is expected to occur given the near-equilibrium nature of the SiCl₄ process. The predominance of {111} facets obtained under these conditions promotes the growth of 〈110〉 SiNWs.