Particulate contamination formed by homogeneous clustering reactions of silicon-hydrogen species within silicon chemical vapor deposition processes is an important source of yield loss during semiconductor processing. On the other hand, intentional synthesis of silicon nanoparticles is of great interest because of the unique optical and electronic properties of nanostructured silicon. Thus, fundamental understanding of the various interconnected mechanisms involved in the particle formation, such as gas phase and gas-surface phase kinetics and particle size/morphology evolution through nucleation, growth, coagulation and coalescence, is of critical importance in optimizing reactor designs and operation conditions in these processes.

In this work, silicon nanoparticle synthesis by silane decomposition in a six-way cross laser driven aerosol reactor was simulated. Because of the complexity of the problem at hand, the simulation was carried out via several sub-models. First, the chemically reacting flow inside the reactor was simulated with a single chemical reaction using MPSalsa, a finite element program developed by Sandia National Laboratories. Second, the reaction zone was simulated by an axisymmetric 2-D MPSalsa model, whose boundary conditions were obtained from the first step. Last, a 2-D aerosol dynamics model was used to study the silicon nanoparticle formation using more complicated silane decomposition chemistry, together with the temperature and velocities extracted from the reaction zone simulation.