Growth of Diamond from Sputtered Atomic Carbon and Atomic Hydrogen

1992 ◽  
Vol 270 ◽  
Author(s):  
Darin S. Olson ◽  
Michael A. Kelly ◽  
Sanjiv Kapoor ◽  
Stig B. Hagstrom

ABSTRACTDiamond thin films were grown on a scratched silicon crystal surface by a novel CVD technique. The substrate was exposed to a bombardment of sputtered carbon atoms from a graphite target in a helium DC glow discharge, and subsequently exposed to atomic hydrogen generated by a hot tungsten filament. The resulting diamond films were characterized by Raman spectroscopy and SEM. Deposited film quality, and growth rate are presented as a function of carbon flux, and atomic hydrogen flux. The observed increase in growth rate with atomic hydrogen indicates that a surface reaction mechanism may be responsible for growth. The saturation of the utilization of carbon confirms that the diamond growth is probably a surface reaction. Based on this work we propose that the growth of diamond films in the sequential CVD reactor is most likely governed by surface reactions, and that the necessity of gas phase precursors can be precluded.

1992 ◽  
Vol 242 ◽  
Author(s):  
Michael A. Kelly ◽  
Sanjiv Kapoor ◽  
Darin S. Olson ◽  
Stig B. Hagstrom

ABSTRACTDiamond thin films were grown on a scratched silicon crystal surface by a novel CVD technique. The heated substrate, mounted on a rotating platform, was exposed to a bombardment of sputtered carbon atoms, from a graphite target in a helium plasma, and subsequently bombarded by atomic hydrogen generated by a hot tungsten filament. The resulting diamond films were characterized by Raman spectroscopy and SEM. The SEM images indicate highly faceted diamond crystals and the Raman spectra show a single narrow peak characteristic of pure diamond with no graphitic component. The effective growth rate is about 0.5 microns per hour of exposure time. The novel sequential CVD reactor is described and possible growth mechanisms are discussed.


1989 ◽  
Vol 4 (5) ◽  
pp. 1243-1245 ◽  
Author(s):  
P. H. Fang ◽  
J. H. Kinnier

In current processes of diamond growth, the substrate temperature is in general around 600–900 °C. In the case of diamond-like carbon, the substrate temperature is lower, around 25–200 °C. There are many superior properties of diamond compared with diamond-like carbon; however, the high temperature requirement to grow diamond precludes many technologically important substrate materials such as zinc sulfide for an infrared window or electronic devices on which protective diamond layers are to be coated. The present approach is a hot filament DC glow discharge of hydrocarbon gases. A graphite hot filament cathode is inserted in a discharge cylinder tube anode. The discharge voltage is in the range of 50 to 250 volts at a methane gas pressure of about 100 microns. A negative biased voltage of 100 volts is applied between the cathode and the substrate. A magnetic field of 1 kG is applied near the cathode-anode assembly. At a substrate temperature of 200–400 °C, the deposited film on silicon crystal is confirmed by an electron diffraction pattern to consist of microcrystalline diamond.


1997 ◽  
Vol 12 (5) ◽  
pp. 1237-1252 ◽  
Author(s):  
Lua'y A. Zeatoun ◽  
Philip W. Morrison

Diamond growth conditions for an atmospheric combustion flame have been optimized using statistical experimental design. Films are grown on a molybdenum bolt for 40 min at a distance of 1 mm from the flame cone. The diamond films have been characterized using Raman spectroscopy, x-ray diffraction, and scanning electron microscope. The input process variables are varied over a range of conditions: total gas flow rate Q = 2–4 standard liter/min, substrate surface temperature Ts = 800–1000 °C, and flow ratio of O2/C2H2 = R = 0.93–0.99. The experimental response outputs are growth rate, full width half maximum (FWHM) of the diamond Raman peak, Raman diamond fraction (β) in the film, ratio of luminescence to diamond peak height (LR), and the relative intensity of the {220}, {311}, {400}, and {331} orientations. The film quality indices FWHM, β, and LR improve by increasing the gas ratio (R), by increasing substrate surface temperature (Ts), and lowering the growth rate by decreasing total gas flow rate. Diamond film shows a small amount texturing in {220} and {400} orientation at low R and Ts. At high R and low Ts crystals are oriented with the {111} direction normal to the substrate surface. Jet and boundary layer theory have been applied to understand the growth rate, the thickness profile, and the morphological instability of the diamond films. Surface Damkühler calculation shows that the deposition process is marginally controlled by mass transfer. Growth rate of an open flame is higher than for an enclosed flame, while the Raman quality measurements of the enclosed flame are more uniform than open flame over the range of the comparison.


1999 ◽  
Vol 14 (9) ◽  
pp. 3720-3724 ◽  
Author(s):  
Naira M. Balzaretti ◽  
Albert Feldman ◽  
Edgar S. Etz ◽  
Roy Gat

The in-plane thermal diffusivity of chemical-vapor-deposited diamond films was measured as a function of diamond-growth rate. The films, 0.1–0.4 mm thick, were prepared in microwave-plasma reactor at growth rates ranging from 1 to 10 μm/h. A modification of Ångstöm's method was used to perform the diffusivity measurements. The thermal conductivity calculated from the thermal diffusivity shows an inverse relationship with growth rate. Analyses of Raman spectra indicate that both the line shifts and the line widths of the diamond Raman peak are practically independent of the deposition rate, except for the specimen grown at the highest growth rate.


1988 ◽  
Vol 53 (12) ◽  
pp. 2995-3013
Author(s):  
Emerich Erdös ◽  
Jindřich Leitner ◽  
Petr Voňka ◽  
Josef Stejskal ◽  
Přemysl Klíma

For a quantitative description of the epitaxial growth rate of gallium arsenide, two models are proposed including two rate controlling steps, namely the diffusion of components in the gas phase and the surface reaction. In the models considered, the surface reaction involves a reaction triple - or quadruple centre. In both models three mechanisms are considered which differ one from the other by different adsorption - and impact interaction of reacting particles. In every of the six cases, the pertinent rate equations were derived, and the models have been confronted with the experimentally found dependences of the growth rate on partial pressures of components in the feed. The results are discussed with regard to the plausibility of individual mechanisms and of both models, and also with respect to their applicability and the direction of further investigations.


Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 426
Author(s):  
Byeong-Kwan Song ◽  
Hwan-Young Kim ◽  
Kun-Su Kim ◽  
Jeong-Woo Yang ◽  
Nong-Moon Hwang

Although the growth rate of diamond increased with increasing methane concentration at the filament temperature of 2100 °C during a hot filament chemical vapor deposition (HFCVD), it decreased with increasing methane concentration from 1% CH4 –99% H2 to 3% CH4 –97% H2 at 1900 °C. We investigated this unusual dependence of the growth rate on the methane concentration, which might give insight into the growth mechanism of a diamond. One possibility would be that the high methane concentration increases the non-diamond phase, which is then etched faster by atomic hydrogen, resulting in a decrease in the growth rate with increasing methane concentration. At 3% CH4 –97% H2, the graphite was coated on the hot filament both at 1900 °C and 2100 °C. The graphite coating on the filament decreased the number of electrons emitted from the hot filament. The electron emission at 3% CH4 –97% H2 was 13 times less than that at 1% CH4 –99% H2 at the filament temperature of 1900 °C. The lower number of electrons at 3% CH4 –97% H2 was attributed to the formation of the non-diamond phase, which etched faster than diamond, resulting in a lower growth rate.


1998 ◽  
Vol 527 ◽  
Author(s):  
Armando Netto ◽  
Michael Frenklach

ABSTRACTDiamond films are of interest in many practical applications but the technology of producing high-quality, low-cost diamond is still lacking. To reach this goal, it is necessary to understand the mechanism underlying diamond deposition. Most reaction models advanced thus far do not consider surface diffusion, but recent theoretical results, founded on quantum-mechanical calculations and localized kinetic analysis, highlight the critical role that surface migration may play in growth of diamond films. In this paper we report a three-dimensional time-dependent Monte Carlo simulations of diamond growth which consider adsorption, desorption, lattice incorporation, and surface migration. The reaction mechanism includes seven gas-surface, four surface migration, and two surface-only reaction steps. The reaction probabilities are founded on the results of quantum-chemical and transition-state-theory calculations. The kinetic Monte Carlo simulations show that, starting with an ideal {100}-(2×1) reconstructed diamond surface, the model is able to produce a continuous film growth. The smoothness of the growing film and the developing morphology are shown to be influenced by rate parameter values and by deposition conditions such as temperature and gaseous species concentrations.


2016 ◽  
Vol 869 ◽  
pp. 721-726 ◽  
Author(s):  
Divani C. Barbosa ◽  
Ursula Andréia Mengui ◽  
Mauricio R. Baldan ◽  
Vladimir J. Trava-Airoldi ◽  
Evaldo José Corat

The effect of argon content upon the growth rate and the properties of diamond thin films grown with different grains sizes are explored. An argon-free and argon-rich gas mixture of methane and hydrogen is used in a hot filament chemical vapor deposition reactor. Characterization of the films is accomplished by scanning electron microscopy, Raman spectroscopy and high-resolution x-ray diffraction. An extensive comparison of the growth rate values and films morphologies obtained in this study with those found in the literature suggests that there are distinct common trends for microcrystalline and nanocrystalline diamond growth, despite a large variation in the gas mixture composition. Included is a discussion of the possible reasons for these observations.


1996 ◽  
Vol 37 (1) ◽  
pp. 18-23
Author(s):  
V. M. Pinchuk ◽  
A. N. Nazarov ◽  
V. S. Lysenko ◽  
V. M. Kovalev

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