Computational Study of Surface Deposition and Gas Phase Powder Formation during Spinel Chemical Vapor Deposition Processes

2013 ◽  
Vol 52 (44) ◽  
pp. 15270-15280 ◽  
Author(s):  
Hangyao Wang ◽  
Heather A. G. Stern ◽  
Debashis Chakraborty ◽  
Hua Bai ◽  
Vincent DiFilippo ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Gas Phase ◽  
Vapor Deposition ◽  
Computational Study ◽  
Chemical Vapor ◽  
Surface Deposition ◽  
Powder Formation ◽  
Deposition Processes

Computational Study of Reactive Flow in Halide Chemical Vapor Deposition of Silicon Carbide Epitaxial Film

2008 ◽  
Author(s):  
Rong Wang ◽  
Ronghui Ma
Keyword(s):  
Chemical Vapor Deposition ◽  
Gas Phase ◽  
Deposition Rate ◽  
Vapor Deposition ◽  
Computational Study ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Large Temperature ◽  
Processing Conditions ◽  
Wide Range

In this study, a comprehensive transport model is developed for Halide Chemical Vapor Deposition (HCVD) system which includes gas dynamics, heat and mass transfer, gas-phase and surface chemistry, and radio-frequency induction heating. This model addresses transport of multiple chemical species in high temperature environment with large temperature difference and complex chemical reactions in gas-phase and on the deposition surface. Numerical modeling of the deposition process in a horizontal hot-wall reactor using SiCl4/C3H8/H2 as precursors has been performed over a wide range of operational parameters to quantify the effects of processing parameters on the film growth. The simulations of the deposition process provide detailed information on the gas-phase composition as well as the distributions of gas velocity and temperature in the reactor. The deposition rate on the substrate surface is also predicted. The results illustrate that deposition temperature and the flow rate of carrier gas play an important role in determining the processing conditions and deposition rate. A high concentration of HCl exists in the growth chamber and the etching of the SiC films by HCl has significant effect on the deposition rate. The modeling approach can be further used to improve reactor design and optimization of processing conditions.

Effects of Feed Gas Composition and Catalyst Thickness on Carbon Nanotube and Nanofiber Synthesis by Plasma Enhanced Chemical Vapor Deposition

2008 ◽  
Vol 8 (6) ◽  
pp. 3068-3076 ◽  
Author(s):  
R. K. Garg ◽  
S. S. Kim ◽  
D. B. Hash ◽  
J. P. Gore ◽  
T. S. Fisher
Keyword(s):  
Carbon Nanotubes ◽  
Phase Composition ◽  
Chemical Vapor Deposition ◽  
Carbon Nanotube ◽  
Gas Phase ◽  
Vapor Deposition ◽  
Computational Study ◽  
Chemical Vapor ◽  
Gas Composition ◽  
Hydrogen Mixture

Many engineering applications require carbon nanotubes with specific characteristics such as wall structure, chirality and alignment. However, precise control of nanotube properties grown to application specifications remains a significant challenge. Plasma-enhanced chemical vapor deposition (PECVD) offers a variety of advantages in the synthesis of carbon nanotubes in that several important synthesis parameters can be controlled independently. This paper reports an experimental study of the effects of reacting gas composition (percentage methane in hydrogen) and catalyst film thickness on carbon nanotube (CNT) growth and a computational study of gas-phase composition for the inlet conditions of experimentally observed carbon nanotube growth using different chemical reaction mechanisms. The simulations seek to explain the observed effects of reacting gas composition and to identify the precursors for CNT formation. The experimental results indicate that gas-phase composition significantly affects the synthesized material, which is shown to be randomly aligned nanotube and nanofiber mats for relatively methane-rich inlet gas mixtures and non-tubular carbon for methane-lean incoming mixtures. The simulation results suggest that inlet methane-hydrogen mixture coverts to an acetylene-methane-hydrogen mixture with minor amounts of ethylene, hydrogen atom, and methyl radical. Acetylene appears to be the indicator species for solid carbon formation. The simulations also show that inlet methane-hydrogen mixture does not produce enough gas-phase precursors needed to form quality CNTs below 5% CH4 concentrations in the inlet stream.

scholarly journals Gas Phase Chemistry of Trimethylboron in Thermal Chemical Vapor Deposition

2017 ◽  
Vol 121 (47) ◽  
pp. 26465-26471 ◽  
Author(s):  
Mewlude Imam ◽  
Laurent Souqui ◽  
Jan Herritsch ◽  
Andreas Stegmüller ◽  
Carina Höglund ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Gas Phase ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Thermal Chemical Vapor Deposition ◽  
Gas Phase Chemistry ◽  
Phase Chemistry
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