Silicon Chemical Vapor Deposition on macro and submicron powders in a fluidized bed

Loïc Cadoret (1) , Nicolas Reuge (1) , S. Pannala (2) , Madhava Syamlal (3) , Cécile Rossignol (4) , Jeannette Dexpert-Ghys (4) , Carole Coufort-Saudejaud (1) , Brigitte Caussat (1)

1 LGC - Laboratoire de Génie Chimique
2 Computer Science and Mathematics Division [Oak Ridge]
3 National Energy Technology Laboratory
4 CEMES - Centre d'élaboration de matériaux et d'études structurales

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% consists of agglomerates in millimetre range found near the distributor 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 in order to achieve better predictability of the phenomena governing ultrafine particles.

Mots clés: Fluidized Bed; Chemical Vapor Deposition (CVD); Submicron powders; Silicon; Process modelling

Domaines: Matériaux

Loïc Cadoret, Nicolas Reuge, S. Pannala, Madhava Syamlal, Cécile Rossignol, et al.. Silicon Chemical Vapor Deposition on macro and submicron powders in a fluidized bed. Powder Technology, 2009, 190 (1-2), pp. 185-191. ⟨10.1016/j.powtec.2008.04.083⟩. ⟨hal-00417365⟩