Zahi, Ilyes and Vergnes, Hugues and Caussat, Brigitte and Estève, Alain and Djafari Rouhani, Mehdi and Mur, Pierre and Blaise, Philippe and Scheid, Emmanuel Modeling of Silicon Nanodots Nucleation and Growth Deposited by LPCVD on SiO2 : From Molecule/Surface Interactions to Reactor Scale Simulations. (2007) In: MRS Fall Meeting 2006, November - December 2006, Boston .
(Document in English)
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We present first results combining models at continuum and atomistic (DFT, Density Functional Theory) levels to improve understanding of key mechanisms involved in silicon nanodots (NDs) synthesis on SiO2 silicon dioxide surface, by Low Pressure Chemical Vapor Deposition (LPCVD) from silane SiH4. In particular, by simulating an industrial LPCVD reactor using the CFD (Computational Fluid Dynamics) code Fluent, we find that deposition time could be increased and then reproducibility and uniformity of NDs deposition could be improved by highly diluting silane in a carrier gas. A consequence of this high dilution seems to be that the contribution to deposition of unsaturated species such as silylene SiH2 highly increases. This result is important since our first DFT calculations have shown that silicon chemisorption on silanol Si-OH or siloxane Si-O-Si bonds present on SiO2 substrates could only proceed from silylene (and probably from other unsaturated species). The silane saturated molecule could only contribute to NDs growth, i.e. silicon chemisorption on already deposited silicon bonds. Increasing silylene contribution to deposition in highly diluting silane could then also exalt silicon nucleation on SiO substrates and then increase NDs density.
|Item Type:||Conference or Workshop Item (Paper)|
|Additional Information:||Published in Quantum Dots—Growth, Behavior and Applications edited E.A. Stach, C.R. Taylor, Z.M. Wang, Q-K. Xue (Materials Research Society Symposium Proceedings Vol. 959-M17-12, 2007).|
|Audience (conference):||International conference proceedings|
|Institution:||Université de Toulouse > Institut National Polytechnique de Toulouse - INPT|
French research institutions > Commissariat à l'Energie Atomique et aux énergies alternatives - CEA
Université de Toulouse > Université Paul Sabatier-Toulouse III - UPS
Université de Toulouse > Institut National des Sciences Appliquées de Toulouse - INSA
French research institutions > Centre National de la Recherche Scientifique - CNRS
|Deposited By:||Brigitte CAUSSAT-BONNANS|
|Deposited On:||28 Apr 2009 11:17|
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