Silicon chemical vapor deposition on macro and submicron powders in a fluidized bed

Abstract

Titanium oxide (TiO2) submicron powders have been treated by Chemical Vapor Deposition (CVD) in a vibro fluidized bed in order to deposit silicon layers of nanometer scale on each individual grain from silane (SiH4). Experimental results show that for the conditions tested, the original granular structure of the powders is preserved for 90% of the initial bed weight while the remaining 10% consisted of agglomerates in millimetre range found near the grid of the reactor. A comparison between experimental and modelling results using the MFIX code shows that for Geldart’s group B alumina particles (Al2O3), the model represents both the bed hydrodynamics and silane conversion rates quite well. The future objective is to extend the simulation capability to cohesive submicron powders