Mechanism Studies on CVD of Boron Carbide from a Gas Mixture of BCl3, CH4, and H-2 in a Dual Impinging-jet Reactor

Date

2009-03-01

Author

Karaman, Mustafa
Sezgi, Naime Aslı
Doğu, Timur
Ozbelge, Hilmi Onder

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Nearly pure boron carbide free from impurities was produced on a tungsten substrate in a dual impinging-jet chemical vapor deposition reactor from a BCl3, CH4, and H-2 mixture. The Fourier Tran form Infrared (FTIR) analysis proved the formation Of reaction intermediate BHCl2, which is proposed to occur mainly in the gaseous boundary layer next to the substrate surface. Among a large number of reaction mechanisms proposed only the ones considering the molecular adsorption of boron carbide on the substrate surface gave reasonable fits. In the proposed mechanism dichloroborane is formed in the gas phase only as a by-product. Boron carbide, on the other hand, is formed through a series of surface reactions involving adsorbed boron trichloride, adsorbed methane and gas phase hydrogen. The simultaneous fit of the experimental rate data to the model expressions gave correlation coefficient values of 0.977 and 0.948, in predicting the B4C and BHCl2 formation rates, respectively. (c) 2009 American Institute of Chemical Engineers AIChE J, 55: 701-709, 2009

Subject Keywords

Adsorption/gas, Deposition methods (CVD, MOCVD), Reaction kinetics

URI

https://hdl.handle.net/11511/30131

Journal

AICHE JOURNAL

DOI

https://doi.org/10.1002/aic.11717

Collections

Graduate School of Natural and Applied Sciences, Article

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Chemical vapor deposition of boron carbide Karaman, Mustafa; Özbelge, Önder; Department of Chemical Engineering (2007) Boron carbide was produced on tungsten substrate in a dual impinging-jet CVD reactor from a gas mixture of BCl3, CH4, and H2. The experimental setup was designed to minimise the effect of mass transfer on reaction kinetics, which, together with the on-line analysis of the reactor effluent by FTIR, allowed a detailed kinetic investigation possible. The phase and morphology studies of the products were made by XPS, XRD,micro hardness and SEM methods. XPS analysis showed the existence of chemical states attrib...

Citation Formats

M. Karaman, N. A. Sezgi, T. Doğu, and H. O. Ozbelge, “Mechanism Studies on CVD of Boron Carbide from a Gas Mixture of BCl3, CH4, and H-2 in a Dual Impinging-jet Reactor,” AICHE JOURNAL, pp. 701–709, 2009, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/30131.