Kinetics of Individual Nucleation Events Observed in Nanoscale Vapor-Liquid-Solid Growth
B. J. Kim,1
J. Tersoff,2
S. Kodambaka,2*
M. C. Reuter,2
E. A. Stach,1
F. M. Ross2
We measured the nucleation and growth kinetics of solid silicon
(Si) from liquid gold-silicon (AuSi) catalyst particles as the
Si supersaturation increased, which is the first step of the
vapor-liquid-solid growth of nanowires. Quantitative measurements
agree well with a kinetic model, providing a unified picture
of the growth process. Nucleation is heterogeneous, occurring
consistently at the edge of the AuSi droplet, yet it is intrinsic
and highly reproducible. We studied the critical supersaturation
required for nucleation and found no observable size effects,
even for systems down to 12 nanometers in diameter. For applications
in nanoscale technology, the reproducibility is essential, heterogeneity
promises greater control of nucleation, and the absence of strong
size effects simplifies process design.
2 IBM Research Division T. J. Watson Research Center, Yorktown Heights, NY 10598, USA.
* Present address: Department of Materials Science and Engineering, University of California Los Angeles, Los Angeles, CA 90095, USA.
To whom correspondence should be addressed. E-mail: eastach{at}purdue.edu (E.A.S.); fmross{at}us.ibm.com (F.M.R.)
