Mechanism and characterization studies on boron carbides deposited by chemical vapor deposition technique

2005-12-02
Karaman, Mustafa
Özbelge, Hilmi Önder
Sezgi, Naime Aslı
Doğu, Timur
Boron carbide was produced in an impinging jet CVD reactor from a gas mixture of BCl3, CH4 and H-2. The mass transfer limitations on the reaction kinetics were minimised by the jet impingement on the substrate surface. XPS characterization of the produced deposits revealed a nearly pure boron carbide phase containing small amounts of oxy-boron and oxy-carbon species. After a detailed kinetic study, a reaction model was proposed to predict the rates of boron carbide and dichloroborane formation reactions. In this model, boron trichloride is adsorbed on the surface non-dissociatively, whereas hydrogen and methane are adsorbed dissociatively. BC is formed on the solid surface through the reaction of adsorbed boron trichloride with adsorbed methane in the form of CH3(S) (adsorbed CH3 on the surface). Produced BC is reacted in successive series reactions including adsorbed boron trichloride and adsorbed hydrogen. In the proposed mechanism, dichloroborane is produced only through the gas phase reaction between boron trichloride and hydrogen. The simultaneous fit of the experimental data to the model expression gave good fits for the boron carbide and dichloroborane formation reactions with the high correlation coefficient values.
Symposium on Materials and Technologies for Direct Thermal-to-Electric Energy Conversion held at the 2005 MRS Fall Meeting

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Citation Formats
M. Karaman, H. Ö. Özbelge, N. A. Sezgi, and T. Doğu, “Mechanism and characterization studies on boron carbides deposited by chemical vapor deposition technique,” Boston, MA, 2005, vol. 886, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/53495.