Vapor-Liquid-Solid Growth of <110> Silicon Nanowire Arrays

摘要

The epitaxial growth of <110> silicon nanowires on (110) Si substrates by the vapor-liquid-solid growth process was investigated using SiCl_4 as the source gas. A high percentage of <110> nanowires was obtained at high temperatures and reduced SiCl_4 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 SiCl_4 process. The predominance of {111} facets obtained under these conditions promotes the growth of <110> SiNWs.