Thermal Diffusion Effects in Chemical Vapor Deposition Reactors

Abstract

A mathematical model that describes the behavior of chemical vapor deposition reactors with well‐defined hydrodynamics has been extended to include the effects of multicomponent thermal diffusion. The influence of thermal diffusion on the deposition rate is dependent on the deposition system and on the operating conditions of the reactor. For production of silicon by reduction of silicon tetrachloride in excess hydrogen, deposition rates are typically lowered by 15–20%. However, for deposition of boron from boron trichloride and hydrogen, thermal diffusion can raise growth rates by approximately 7% when concentrated inlet gas mixtures are used.