Experimental and Modeling Studies on the Nucleation and Growth of
Silicon Nanoparticles from the Vapor Phase
Mark
T. Swihart
Department of Chemical Engineering
University at Buffalo (SUNY), Buffalo, NY 14260, USA
Synthesis
of semiconductor nanoparticles is of great interest due to their unique,
size-dependent optical and electronic properties. Controllable production of nanoparticles of desired size and
composition would benefit from an improved understanding of particle nucleation
and growth, and from the ability to quantitatively model these processes. On the other hand, particulate contamination
due to particles nucleated within processing equipment is an important source
of yield loss in microelectronics manufacturing. To control this unwanted
homogeneous nucleation of particles, again, we must understand and be able to
quantitatively model the nucleation process.
We are developing chemical kinetic models for the nucleation of silicon
particles. These models allow us to identify key reaction pathways for
nucleation and to predict particle nucleation rates and incorporate them into
aerosol dynamics models of processing equipment that include descriptions of
particle growth, coagulation, and transport.
At the same time, we are conducting experiments on the vapor-phase
synthesis of semiconductor nanoparticles in a laser-driven reactor system. We have succeeded in producing sub-10-nm
diameter non-agglomerated crystalline silicon nanoparticles, as well as
agglomerates with comparable primary particle size in much higher
concentrations. This talk will present
a brief overview of our work in these areas, including:
(1) Manual and automated
construction of chemically detailed models of the nucleation of silicon
nanoparticles during gas-phase thermal decomposition of silane
(2) Incorporation of these
models into aerosol dynamics models to predict particle concentrations and size
distributions in simple reactor geometries;
(3) Production of silicon
nanoparticles in our laser-driven aerosol reactor system and dependence of
nanoparticle size and properties on reaction conditions; and
(4) Post-processing and
characterization of these silicon nanoparticles to achieve photoluminescence
properties useful for applications in microelectronics, nanophotonics, and
bio-imaging.