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.

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.

scholarly journals Low Temperature Growth of Ultra-Nanocrystalline Diamond on Glass Substrates for Field Emission Applications

1999 ◽  
Vol 593 ◽  
Author(s):  
T. D. Corrigan ◽  
A. R. Krauss ◽  
D. M. Gruen ◽  
O. Auciello ◽  
R. P. H. Chang
Keyword(s):  
Chemical Vapor Deposition ◽  
Field Emission ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Cost Effective ◽  
Cvd Diamond ◽  
Glass Substrates ◽  
Cvd Method

ABSTRACTRecent studies of field emission from diamond have focused on the feasibility of growing diamond films on glass substrates, which are the preferred choice for cost-effective, large area flat panel displays. However, diamond growth on glass requires temperatures < 500 °C, which is much lower than the temperature needed for growing conventional microwave plasma chemical vapor deposition (CVD) diamond films. In addition, it is desirable to minimize the deposition time for cost-effective processing. We have grown ultrananocrystalline diamond (UNCD) films using a unique microwave plasma technique that involves CH4-Ar gas mixtures, as opposed to the conventional CH4-H2 plasma CVD method. The growth species in the CH4-Ar CVD method are C2 dimers, resulting in lower activation energies and consequently the ability to grow diamond at lower temperatures than conventional CVD diamond processes. For the work discussed here, the UNCD films were grown with plasma-enhanced chemical vapor deposition (PECVD) at low temperatures on glass substrates coated with Ti thin films. The turn-on field was as low as 3 V/μm for a film grown at 500 °C with a gas chemistry of l%CH4/99%Ar at 100 Torr, and 7 V/μm for a film grown at 350 °C. UV Raman spectroscopy revealed the presence of high quality diamond in the films.

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.

Study of Undoped Nanocrystalline Diamond Films Grown by Microwave Plasma-Assisted Chemical Vapor Deposition

2021 ◽  
Vol 55 (1) ◽  
pp. 66-75
Author(s):  
A. L. Vikharev ◽  
S. A. Bogdanov ◽  
N. M. Ovechkin ◽  
O. A. Ivanov ◽  
D. B. Radishev ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Nanocrystalline Diamond ◽  
Nanocrystalline Diamond Films

Evolution of surface relief of epitaxial diamond films upon growth resumption by microwave plasma chemical vapor deposition

CrystEngComm ◽  
2020 ◽  
Vol 22 (12) ◽  
pp. 2138-2146 ◽  
Author(s):  
G. Shu ◽  
V. G. Ralchenko ◽  
A. P. Bolshakov ◽  
E. V. Zavedeev ◽  
A. A. Khomich ◽  
...  
Keyword(s):  
Vapor Deposition ◽  
Surface Relief ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Diamond Growth ◽  
Plasma Chemical ◽  
Plasma Chemical Vapor Deposition ◽  
Step Growth ◽  
Growth Features

Homoepitaxial diamond growth may proceed with stops and resumptions to produce thick crystals. We found the resumption procedure to take place in a complex way, via a disturbance of step growth features, followed by the recovery after a certain time.

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