Imaging and Modeling C2 Radical Emissions from Microwave Plasma-Activated Methane/Hydrogen Gas Mixtures: Contributions from Chemiluminescent Reactions and Investigations of Higher-Pressure Effects and Plasma Constriction

2021 ◽  
Author(s):  
Joseph P. P. Gore ◽  
Edward J. D. Mahoney ◽  
James A. Smith ◽  
Michael N. R. Ashfold ◽  
Yuri A. Mankelevich
Keyword(s):  
Microwave Plasma ◽  
Gas Mixtures ◽  
Hydrogen Gas ◽  
Pressure Effects

Characterization of diamond thin films: Diamond phase identification, surface morphology, and defect structures

1989 ◽  
Vol 4 (2) ◽  
pp. 373-384 ◽  
Author(s):  
B. E. Williams ◽  
J. T. Glass
Keyword(s):  
Electron Microscopy ◽  
Surface Morphology ◽  
Methane Concentration ◽  
Microwave Plasma ◽  
Defect Density ◽  
Diamond Films ◽  
Hydrogen Gas ◽  
Phase Identification ◽  
Diamond Crystals ◽  
Thin Carbon

Thin carbon films grown from a low pressure methane-hydrogen gas mixture by microwave plasma enhanced CVD have been examined by Auger electron spectroscopy, secondary ion mass spectrometry, electron and x-ray diffraction, electron energy loss spectroscopy, and electron microscopy. They were determined to be similar to natural diamond in terms of composition, structure, and bonding. The surface morphology of the diamond films was a function of position on the sample surface and the methane concentration in the feedgas. Well-faceted diamond crystals were observed near the center of the sample whereas a less faceted, cauliflower texture was observed near the edge of the sample, presumably due to variations in temperature across the surface of the sample. Regarding methane concentration effects, threefold {111} faceted diamond crystals were predominant on a film grown at 0.3% CH4 in H2 while fourfold {100} facets were observed on films grown in 1.0% and 2.0% CH4 in H2. Transmission electron microscopy of the diamond films has shown that the majority of diamond crystals have a very high defect density comprised of {111} twins, {111} stacking faults, and dislocations. In addition, cross-sectional TEM has revealed a 50 Å epitaxial layer of β3–SiC at the diamond-silicon interface of a film grown with 0.3% CH4 in H2 while no such layer was observed on a diamond film grown in 2.0% CH4 in H2.

Synthesis of 3-dimensional porous graphene nanosheets using electron cyclotron resonance plasma enhanced chemical vapour deposition

RSC Advances ◽  
2015 ◽  
Vol 5 (103) ◽  
pp. 84927-84935 ◽  
Author(s):  
Rajesh Thomas ◽  
G. Mohan Rao
Keyword(s):  
Chemical Vapour Deposition ◽  
Vapour Deposition ◽  
Electron Cyclotron Resonance ◽  
Microwave Plasma ◽  
Graphene Nanosheets ◽  
Chemical Vapour ◽  
Hydrogen Gas ◽  
3 Dimensional ◽  
Gas Molecules ◽  
Resonance Plasma

Microwave plasma driven chemical vapour deposition was used to synthesize graphene nanosheets from a mixture of acetylene and hydrogen gas molecules.

Oxygen Effect in Diamond Deposition at Low Temperatures

1989 ◽  
Vol 162 ◽  
Author(s):  
Y. Liou ◽  
A. Inspektor ◽  
R. Weimer ◽  
D. Knight ◽  
R. Messier
Keyword(s):  
Thin Films ◽  
Low Temperatures ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Gas Mixtures ◽  
Diamond Growth ◽  
Oxygen Effect ◽  
Gas Mixture ◽  
Diamond Thin Films ◽  
Deposited Films

ABSTRACTDiamond thin films were deposited on different substrates at low temperatures (lowest temperature∼ 300°C, estimated) in a microwave plasma enhanced chemical vapor deposition (MPCVD) system. The deposited films were amorphous carbon or diamond films depending on the different gas mixtures used. The growth rate of diamond thin films was decreased by adding oxygen to the gas mixture. The addition of oxygen to the gas mixtures was found to be important for diamond growth at low temperatures. Different concentrations of oxygen have been added into the gas mixture. Without oxygen, the deposited films were white soots and easily scratched off. Increasing the oxygen input improved the quality of the Raman peaks and increased the film transpancy. The diamond films were also characterized by scanning electron microscopy (SEM).

Mechanism of microwave plasma etching of polyimides in O2 and CF4 gas mixtures

1986 ◽  
Vol 5 (1-4) ◽  
pp. 375-386 ◽  
Author(s):  
N.J. Chou ◽  
J. Parazsczak ◽  
E. Babich ◽  
Y.S. Chaug ◽  
R. Goldblatt
Keyword(s):  
Plasma Etching ◽  
Microwave Plasma ◽  
Gas Mixtures

Influence of Electrode Argon-Hydrogen Co-Injection on Carbon Content in a Alternating Current Ladle Furnace

2011 ◽  
Vol 239-242 ◽  
pp. 2361-2364
Author(s):  
Dong Ping Zhan ◽  
Hui Shu Zhang ◽  
Zhou Hua Jiang ◽  
Wei Gong ◽  
Zhao Ping Chen
Keyword(s):  
Reaction Rate ◽  
Local Equilibrium ◽  
Low Carbon Steel ◽  
Alternating Current ◽  
Gas Mixtures ◽  
Electric Arc ◽  
Hydrogen Gas ◽  
Ladle Furnace ◽  
Low Carbon ◽  
Decarburization Rate

About 80 kg low carbon steel was refined in a multifunction ladle furnace (AC-LF) with alternating current supplying. The argon-hydrogen gas mixtures were injected into the electric arc zone through one hollow graphite electrode. The flow rate of the gas mixtures was 3 m3/h. Results of the tests and the calculation based on the plasma local equilibrium thermodynamics and metallurgical thermodynamics theories show that, when the argon-hydrogen gas mixtures are injected into the electric arc zone, the carburetion rate is 4.7×10-6per minute for the steel heated by conventional AC-LF, which is 1.26 and 1.51 times of the heats blown 90%Ar-10%H2and 80%Ar-20%H2, respectively. The carburetion rate is reduced by 20% at least when argon-hydrogen gas mixtures are blown into the furnace. When H2content in the gas mixtures reached 20% from 0, the decarburization rate increased but the total reaction rate decreases by 1.59×10-6per minute.

scholarly journals Catalyst-Less and Transfer-Less Synthesis of Graphene on Si(100) Using Direct Microwave Plasma Enhanced Chemical Vapor Deposition and Protective Enclosures

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5630
Author(s):  
Rimantas Gudaitis ◽  
Algirdas Lazauskas ◽  
Šarūnas Jankauskas ◽  
Šarūnas Meškinis
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Gas Flow ◽  
Microwave Plasma ◽  
Lattice Mismatch ◽  
Chemical Vapor ◽  
Hydrogen Gas ◽  
Synthesis Process ◽  
Synthesis Time ◽  
Graphene Layers

In this study, graphene was synthesized on the Si(100) substrates via the use of direct microwave plasma-enhanced chemical vapor deposition (PECVD). Protective enclosures were applied to prevent excessive plasma etching of the growing graphene. The properties of synthesized graphene were investigated using Raman scattering spectroscopy and atomic force microscopy. Synthesis time, methane and hydrogen gas flow ratio, temperature, and plasma power effects were considered. The synthesized graphene exhibited n-type self-doping due to the charge transfer from Si(100). The presence of compressive stress was revealed in the synthesized graphene. It was presumed that induction of thermal stress took place during the synthesis process due to the large lattice mismatch between the growing graphene and the substrate. Importantly, it was demonstrated that continuous horizontal graphene layers can be directly grown on the Si(100) substrates if appropriate configuration of the protective enclosure is used in the microwave PECVD process.

Co-deposition of diamond and β-SiC by microwave plasma CVD in H2-CH4-SiH4 gas mixtures

2019 ◽  
Vol 98 ◽  
pp. 107520 ◽  
Author(s):  
V.S. Sedov ◽  
A.K. Martyanov ◽  
A.A. Khomich ◽  
S.S. Savin ◽  
V.V. Voronov ◽  
...  
Keyword(s):  
Microwave Plasma ◽  
Gas Mixtures ◽  
Plasma Cvd ◽  
Microwave Plasma Cvd

EFFECTS OF HYDROGEN GAS FLOW RATIO ON THE QUALITY OF NANO-DIAMOND FILMS

2002 ◽  
Vol 16 (06n07) ◽  
pp. 876-880
Author(s):  
S. G. Wang ◽  
Q. Zhang ◽  
D. J. Yang ◽  
S. F. Yoon ◽  
J. Ahn ◽  
...  
Keyword(s):  
Grain Size ◽  
Gas Flow ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Gaseous Mixture ◽  
Hydrogen Gas ◽  
Chemical Vapor Deposition Method ◽  
Flow Ratio ◽  
Gas Flow Ratio

In this paper, we studied the effects of hydrogen gas flow ratio of [H2]/[N2 + CH4 + H2] on the quality of nanometer diamond (nano-diamond) films prepared by microwave plasma enhanced chemical vapor deposition method. Nano-diamond films were deposited on the silicon substrates from a gaseous mixture of nitrogen, methane and hydrogen. The experimental results show that if only using a gaseous mixture of nitrogen and methane, although we can obtain nano-diamond films with a grain size of about 5nm, the diamond films contain much non-diamond components. With hydrogen addition, and with increasing the hydrogen gas flow ratio from 1 to 10%, the non-diamond components in the films are significantly reduced and the grain size of the films increases from 5nm to 60nm. However optical transmittance of the films increases with increasing hydrogen gas flow ratio from 1 to 7% because of an improvement of film quality, and then decreases with further increasing hydrogen gas flow ratio owing to the increase of film roughness.

Structure And Stress Evaluation Of Diamond Films Deposited On Ti-6A1-4V Alloy At Low Temperature Using Ch4/O2/H2 And CO/H2 Gas Mixtures

1997 ◽  
Vol 505 ◽  
Author(s):  
Shane A. Catledge ◽  
Yogesh K. Vohra
Keyword(s):  
Low Temperature ◽  
Oxygen Concentration ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Onset Time ◽  
Film Surface ◽  
Chemical Vapor ◽  
Gas Mixtures ◽  
Average Growth ◽  
Plasma Chemical Vapor Deposition

ABSTRACTLow temperature diamond deposition on metal substrates is motivated by the need to reduce thermal stress so that the film adhesion is satisfactory. Although the use of oxygen-con- taining gas mixtures have been shown to extend the temperature range for which diamond can grow as well as to improve film quality, most studies have focused on the use of silicon as sub- strates and have neglected technologically important metallic systems. To this end, microwave plasma chemical vapor deposition (MPCVD) was used to grow diamond films on Ti-6A1-4V alloy at low temperature (615 to 780 C) using CH4/O2/H2 and CO/H2 gas mixtures. In-situ pyrometric interferometry (ISPI) shows that as the oxygen concentration increases, the onset time for dia- mond nucleation and subsequent film surface roughness increases while the average growth rate decreases. Micro-Raman spectroscopy shows improved film quality and suggests a trend toward increasing in-plane compressive stress with increasing oxygen concentration. Glancing-angle x- ray diffraction (XRD) was complimentary to the Raman data and indicates the presence of a TiC interfacial layer thickness which decreases with increasing oxygen concentration. We found that the CO/H2 mixture resulted in poorly adhered “white soot” films with low diamond content whereas the CH4/O2/H2 mixture yielded well adhered high quality diamond films.

Sign in / Sign up

Export Citation Format

Share Document