TITLE:
Microwave Plasma Enhanced Chemical Vapor Deposition of Carbon Nanotubes
AUTHORS:
Ivaylo Hinkov, Samir Farhat, Cristian P. Lungu, Alix Gicquel, François Silva, Amine Mesbahi, Ovidiu Brinza, Cornel Porosnicu, Alexandru Anghel
KEYWORDS:
Nanotubes, Growth, CVD, Modeling, Kinetics
JOURNAL NAME:
Journal of Surface Engineered Materials and Advanced Technology,
Vol.4 No.4,
June
20,
2014
ABSTRACT: Multi-walled carbon
nanotubes (MWCNTs) were grown by plasma-enhanced chemical vapor deposition
(PECVD) in a bell jar reactor. A mixture of methane and hydrogen (CH4/H2)
was decomposed over Ni catalyst previously deposited on Si-wafer by thermionic
vacuum arc (TVA) technology. The growth parameters were optimized to obtain
dense arrays of nanotubes and were found to be: hydrogen flow rate of 90 sccm;
methane flow rate of 10 sccm; oxygen flow rate of 1 sccm; substrate temperature
of 1123 K; total pressure of 10 mbar and microwave power of 342 Watt. Results
are summarized and significant main factors and their interactions were
identified. In addition a computational study of nanotubes growth rate was
conducted using a gas phase reaction mechanism and surface nanotube formation
model. Simulations were performed to determine the gas phase fields for
temperature and species concentration as well as the surface-species coverage
and carbon nanotubes growth rate. A kinetic mechanism which consists of 13 gas
species, 43 gas reactions and 17 surface reactions has been used in the
commercial computational fluid dynamics (CFD) software ANSYS Fluent. A
comparison of simulated and experimental growth rate is presented in this
paper. Simulation results agreed favorably with experimental data.