Role of microstructure on the oxidation behavior of microwave plasma synthesized diamond and diamond-like carbon films

1990 ◽  
Vol 5 (11) ◽  
pp. 2445-2450 ◽  
Author(s):  
Rao R. Nimmagadda ◽  
A. Joshi ◽  
W. L. Hsu
Keyword(s):  
Oxidation Behavior ◽  
Microwave Plasma ◽  
Natural Diamond ◽  
Diamond Films ◽  
Cvd Diamond ◽  
Carbon Films ◽  
Diamond Like Carbon ◽  
Gravimetric Analysis ◽  
Oxidation Rates

Oxidation kinetics of microwave plasma assisted CVD diamond and diamond-like carbon (DLC) films in flowing oxygen were evaluated in the temperature range of 500 to 750 °C and were compared with those of graphite and natural diamond. The diamond and DLC films were prepared using CH4/H2 ratios of 0.1, 0.25, 0.5, 1.0, and 2.0%. The films deposited at 0.1% ratio had a faceted crystalline structure with high sp3 content and as the ratio increased toward 2%, the films contained more and more fine crystalline sp2 bonded carbon. The oxidation rates were determined by thermal gravimetric analysis (TGA), which shows that the films deposited at ratios of 2, 1, and 0.5% oxidized at high rates and lie between the rates of natural diamond and graphite. The oxidation rate decreased with lower CH4/H2 ratio and the films deposited at 0.25 and 0.1% exhibited the lowest oxidation rates associated with the highest activation energies in the range of 293–285 kJ/mol · K. The oxidation behavior of microwave plasma assisted diamond films was similar to that of DC plasma assisted CVD diamond films. The results suggest that the same mechanism of oxidation is operational in both DC and microwave plasma assisted diamond films and is probably related to the microstructure and preferred orientation of the crystallites.

Thermogravimetric analysis of the oxidation of CVD diamond films

1990 ◽  
Vol 5 (11) ◽  
pp. 2320-2325 ◽  
Author(s):  
Curtis E. Johnson ◽  
Michael A.S. Hasting ◽  
Wayne A. Weimer
Keyword(s):  
Thermogravimetric Analysis ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Natural Diamond ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Oxidation Rates ◽  
Air Atmosphere ◽  
Highly Porous

Diamond films grown by microwave plasma assisted chemical vapor deposition (CVD) were studied by thermogravimetric analysis under an air atmosphere. Oxidation rates were measured between 600 and 750 °C to determine an activation energy of 213 kJ/mol which is similar to that reported for natural diamond. The rate of oxidation increases with increasing surface area and decreases with increasing humidity. The oxidation proceeds by etching pits into the film, creating a highly porous structure. Graphitization was not detected in partially oxidized samples by Raman or Auger electron spectroscopy. A film that was heated to 1170 °C under nitrogen remained IR transmissive.

The Role of Atomic Hydrogen and Oxygen in Low Temperature Growth of Diamond by Microwave Plasma Assisted Cvd

1992 ◽  
Vol 270 ◽  
Author(s):  
Y. Muranaka ◽  
H. Yamashita ◽  
H. Miyadera
Keyword(s):  
Low Temperature ◽  
Atomic Hydrogen ◽  
Microwave Plasma ◽  
Natural Diamond ◽  
Diamond Films ◽  
Microwave Plasmas ◽  
Temperature Growth ◽  
Low Temperature Growth ◽  
Good Crystallinity

ABSTRACTDiamond films grown in the microwave plasmas of CO(7–8%)-O2(0–2.2%)-H2 systems in the range of 130–750°C were characterized by scanning electron microscopy, Raman spectroscopy, and cathodoluminescence (CL) studies. The films grown in the CO-O2-H2 system had much better crystallinity than those grown in the CO-H2 system. This was because oxygen extremely purified diamond films by suppressing polyacetylene inclusion, and prohibited the vacancy formation in the crystallites. These oxygen functions have indicated the possibility that high quality diamond films (FWI-tM of the diamond Raman peak =4.0–4. lcm−1) close to natural diamond (FWHM=3.0cm−1) were obtained in the CO(8%)-O2(2.2%)-H2 system between 400 and 750°C. Though crystallinity deterioration occurred at 130°C, the obtained film (FWHM=10.2cm−1) in the CO(8%)-O2(2.2%)-H 2 system was of good crystallinity comparable to those (FWHM=7–21cm−1) grown by conventional CVD processes and gas systems between 590 and 1327°C. The CO-O2-H2 microwave plasma was concluded to be one of the best environment for the low temperature growth of highly purified diamond films of good crystallinity.

An Study of Influence of Imperfections on the Delamination of Diamond-Like Carbon Films

2002 ◽  
Vol 719 ◽  
Author(s):  
Myoung-Woon Moon ◽  
Kyang-Ryel Lee ◽  
Jin-Won Chung ◽  
Kyu Hwan Oh
Keyword(s):  
Cross Sections ◽  
Focused Ion Beam ◽  
Imaging System ◽  
Ion Beam ◽  
Carbon Films ◽  
Diamond Like Carbon ◽  
Glass Substrates ◽  
Atomic Force ◽  
Initiation And Propagation

AbstractThe role of imperfections on the initiation and propagation of interface delaminations in compressed thin films has been analyzed using experiments with diamond-like carbon (DLC) films deposited onto glass substrates. The surface topologies and interface separations have been characterized by using the Atomic Force Microscope (AFM) and the Focused Ion Beam (FIB) imaging system. The lengths and amplitudes of numerous imperfections have been measured by AFM and the interface separations characterized on cross sections made with the FIB. Chemical analysis of several sites, performed using Auger Electron Spectroscopy (AES), has revealed the origin of the imperfections. The incidence of buckles has been correlated with the imperfection length.

Crystalline perfection of chemical vapor deposited diamond films

1990 ◽  
Vol 5 (8) ◽  
pp. 1591-1594 ◽  
Author(s):  
A. V. Hetherington ◽  
C. J. H. Wort ◽  
P. Southworth
Keyword(s):  
Grain Boundaries ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Stacking Faults ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Growth Conditions ◽  
Crystalline Perfection ◽  
Planar Defects ◽  
Chemical Vapor Deposited

The crystalline perfection of microwave plasma assisted chemical vapor deposited (MPACVD) diamond films grown under various conditions has been examined by TEM. Most CVD diamond films thus far reported contain a high density of defects, predominantly twins and stacking faults on {111} planes. We show that under appropriate growth conditions, these planar defects are eliminated from the center of the crystallites, and occur only at grain boundaries where the growing crystallites meet.

The Control Of Intrinsic Stresses In Cvd Diamond Films With Multistep Processing

1995 ◽  
Vol 416 ◽  
Author(s):  
S. Nijhawan ◽  
S. M. Jankovsky ◽  
B. W. Sheldon
Keyword(s):  
Thermal Stresses ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Annealing Treatment ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Internal Stresses ◽  
Tensile Stresses ◽  
Si Substrates

ABSTRACTThe role of intrinsic stresses in diamond films is examined. The films were deposited on (100) Si substrates by microwave plasma-enhanced chemical vapor deposition. The total internal stresses (thermal and intrinsic) were measured at room temperature with the bending plate method. The thermal stresses are compressive and arise due to the mismatch in thermal expansion coefficient of film and substrate. The intinsic stresses were tensile and evolved during the deposition process. These stresses increased with increasing deposition time. A 12 hour intermediate annealing treatment was found to reduce the tensile stresses considerably. The annealing treatment is most effective when the diamond crystallites are undergoing impingement and coalescence. This is consistent with the theory that the maximum tensile stresses are associated with grain boundary energetics.

Structural and mechanical characterization of diamond like carbon films grown by microwave plasma CVD

2010 ◽  
Vol 204 (16-17) ◽  
pp. 2817-2821 ◽  
Author(s):  
Sambita Sahoo ◽  
Swati S. Pradhan ◽  
Venkateswarlu Bhavanasi ◽  
S.K. Pradhan
Keyword(s):  
Mechanical Characterization ◽  
Microwave Plasma ◽  
Carbon Films ◽  
Diamond Like Carbon ◽  
Plasma Cvd ◽  
Microwave Plasma Cvd

Diamond-like carbon films prepared from CH4-H2-H2O mixed gas using a microwave plasma

1989 ◽  
Vol 24 (1) ◽  
pp. 293-297 ◽  
Author(s):  
Yukio Saito ◽  
Kouji Sato ◽  
Hideaki Tanaka ◽  
Hiroshi Miyadera
Keyword(s):  
Microwave Plasma ◽  
Carbon Films ◽  
Diamond Like Carbon ◽  
Mixed Gas

Pretreatment Study on the Deposition of Diamond-Like Carbon Films on Quartz by Star-Shape MPCVD Reactor

2014 ◽  
Vol 912-914 ◽  
pp. 288-292
Author(s):  
Li Wei Xiong ◽  
Guo Hua Gong ◽  
Jian Hua Wang ◽  
Xiao Hui Cui ◽  
Wei Zou
Keyword(s):  
Microwave Plasma ◽  
Chemical Vapor ◽  
Diamond Powder ◽  
Carbon Films ◽  
Diamond Like Carbon ◽  
Pretreatment Time ◽  
Infrared Spectrometer ◽  
Optical Applications ◽  
The Fourier Transform ◽  
Quartz Substrates

Diamond-Like Carbon (DLC) films were deposited on quartz substrates by using a gas mixture of hydrogen-methane-oxygen in the Star-Shape Microwave Plasma enhanced Chemical Vapor Deposition (MPCVD) reactor. The pretreatment parameters include the pretreatment methods and the pretreatment time was optimized. Results showed that ultrasonically abrasive in the acetone solution with nanocrystalline diamond powder in it was an efficient pretreatment method to advance the deposition of DLC films, and 10 minute turned to be the most appropriate time for this pretreatment. The Fourier Transform Infrared spectrometer (FTIR) showed that the DLC films synthesized by the optimized technics have high transparence fit for optical applications. These indicated that the Star-Shape MPCVD reactor was the perfect equipment for the volume-produce of DLC films for its unique big reactive cavity.

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