Numerical Analysis of the Flowfields in a CVD Reactor

摘要

The uniformity of the electric field alone is not sufficient to guarantee the uniformity of the products of PECVD processing when the reactive gases are involved. Depending on their flow pattern in the reactor, the gases can be depleted of the reactive components along their path. Flow pattern produces gradients in concentration, velocity, and temperature throughout the reactor. As we can sec in reaction kinetics, local concentration gradients can produce local variations in reaction rates. And the important geometrical factors that affect flow patterns in a CVD reactor are a showerhead, an outlet and a substrate. In this study, a vertical thermal RF-PECVD reactor is modeled to investigate the flow patterns and the deposition rates with several reactor models. The governing equations are solved for the pressure, mass-flow rates and temperature distributions in a CVD reactor. The relative growth rate is also investigated to present the uniformity of the deposition on the substrate.