(503a) Cluster Formation and Particle Dynamic in Zinc Sulfide Cvd Reactor

Zinc sulfide has a large direct band gap and is widely used in optical devices. A popular method to produce high quality zinc sulfide is chemical vapor deposition (CVD). Operating conditions (e.g. high temperature) in a CVD are usually suitable to enhance adduct formation. The clusters formed may leave the reactor, settle, or deposit on the substrate creating defects on the deposited film. In this presentation we will discuss a two dimensional CFD model which predicts the particle growth and distribution inside the CVD reactor. We employed density functional theory to estimate unknown kinetic parameters (such as nucleation, and surface growth rates) and possible crystal morphology in the gas phase. Our results show that (a) particle diameter will increase with an increase in temperature, and (b) the average particle diameter is higher at the reactor exit. The axial distribution of particles shows larger particle formation rate closer to the reactor inlet which decreases towards the reactor outlet. The clusters morphology varies from bubble-like for small particles to BCT structure for large particles.