Si nanowires grow rapidly by chemical vapor deposition on Ti-containing isl
ands on Si surfaces when an abundant supply of Si-containing gaseous precur
sor is available. The density of wires is approximately the same as the den
sity of the nucleating islands on the Si surface, although at least two dif
ferent types of islands appear to correlate with very different wire growth
rates. For the deposition conditions used, a minority of long, defect-free
wires form, along with more numerous wires containing defects. Energy-disp
ersive x-ray spectroscopy shows that the Ti-containing nanoparticles remain
at the tip of the growing wires. The estimated diffusion coefficient of Si
in TiSi2 is consistent with the catalyzing nanoparticle remaining in the s
olid phase during nanowire growth. (C) 2001 American Institute of Physics.