CVD of boron and dichloroborane formation in a hot-wire fiber growth reactor

Date

2001-11-01

Author

Sezgi, Naime Aslı
Dogu, T
Ozbelge, HO

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Chemical vapor deposition (CVD) of boron by hydrogen reduction of BCl, on a hot tungsten substrate was investigated in a parallel flow reactor. Effect of substrate temperature (1100-1250 degreesC) on the relative rates of formation of BHCl2 and boron was observed by the on-line analysis of the reactor effluent stream composition using an FT-IR spectrophotometer. It was concluded that BHCl2 was majorly formed in the gas phase within the thermal boundary layer adjacent to the substrate with possible contribution of surface reactions at higher temperatures. Comparison of results obtained in the impinging jet and parallel flow reactors indicated the significance of diffusion resistance in the parallel flow system. Tubular flow reactor experiments indicated that BHCl2 formation reaction started at temperatures as low as 350 degreesC and reached equilibrium in less than a second at temperatures over 420 degreesC.

Subject Keywords

Boron fibers, CVD, Dichloroborane, Reaction kinetics

URI

https://hdl.handle.net/11511/32999

Journal

CHEMICAL ENGINEERING AND PROCESSING

DOI

https://doi.org/10.1016/s0255-2701(00)00150-1

Collections

Department of Chemical Engineering, Article

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Mechanism Studies on CVD of Boron Carbide from a Gas Mixture of BCl3, CH4, and H-2 in a Dual Impinging-jet Reactor Karaman, Mustafa; Sezgi, Naime Aslı; Doğu, Timur; Ozbelge, Hilmi Onder (2009-03-01) 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 su...
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BHCl2 formation during chemical vapor deposition of boron in a dual-impinging jet reactor Sezgi, Naime Aslı; Ozbelge, HO (1997-12-01) Chemical vapor deposition (CVD) of boron from BCl3 and Hz was investigated in a dual-impinging jet reactor which was connected to an FT-IR spectrometer for on-line chemical analysis of the reactor outlet stream. Formation of the intermediate, BHCl2, during CVD of boron on a hot tungsten substrate was experimentally verified, Boron deposition started at substrate temperatures of around 750 degrees C and showed a significant deposition rate increase with an increase in temperature. At a surface temperature of...
Kinetic studies for boron carbide formation in a dual impinging-jet reactor Noyan-Dilek, S; Ozbelge, HO; Sezgi, Naime Aslı; Dogu, T (2001-02-07) The chemical vapor deposition (CVD) of boron carbide was investigated on a tungsten substrate from a gas mixture of BCl3, H-2, and CH4 in a dual impinging-jet reactor that was connected to an FT-IR spectrometer for on-line analysis of the reactor effluent stream. During CVD of boron carbide, the formation of BHCl2 was experimentally verified, and beta -rhombohedral B4C was formed. Conversion to boron carbide was found to increase with an increase in the BCl3/CH4 ratio. However, conversion to dichloroborane ...

Citation Formats

N. A. Sezgi, T. Dogu, and H. Ozbelge, “CVD of boron and dichloroborane formation in a hot-wire fiber growth reactor,” CHEMICAL ENGINEERING AND PROCESSING, pp. 525–530, 2001, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/32999.