A One-Dimensional Stochastic Model of Diamond Growth

1995 ◽  
Vol 399 ◽  
Author(s):  
Michael Frenklach

ABSTRACT(1+1)-dimensional stochastic simulations were performed representing elementary processes underlying chemical vapor deposition of diamond films. The results exhibit different growth regimes, depending on the values assigned to kinetic rates, and generally support the critical role of surface migration suggested earlier for the growth of diamond.

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.


1995 ◽  
Vol 10 (11) ◽  
pp. 2685-2688 ◽  
Author(s):  
Qijin Chen ◽  
Zhangda Lin

Diamond film was synthesized on thin Ti wafers (as thin as 40 μm) via hot filament chemical vapor deposition (HFCVD). The hydrogen embrittlement of the titanium substrate and the formation of a thick TiC interlayer were suppressed. A very low pressure (133 Pa) was employed to achieve high-density rapid nucleation and thus to suppress the formation of TiC. Oxygen was added to source gases to lower the growth temperature and therefore to slow down the hydrogenation of the thin Ti substrate. The role of the very low pressure during nucleation is discussed, providing insight into the nucleation mechanism of diamond on a titanium substrate. The as-grown diamond films were characterized by scanning electron microscopy (SEM), Raman spectroscopy, and x-ray analysis.


1995 ◽  
Vol 416 ◽  
Author(s):  
S. Nijhawan ◽  
S. M. Jankovsky ◽  
B. W. Sheldon

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.


CrystEngComm ◽  
2020 ◽  
Vol 22 (12) ◽  
pp. 2138-2146 ◽  
Author(s):  
G. Shu ◽  
V. G. Ralchenko ◽  
A. P. Bolshakov ◽  
E. V. Zavedeev ◽  
A. A. Khomich ◽  
...  

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.


2020 ◽  
Vol 117 (19) ◽  
pp. 194001
Author(s):  
Simon A. Meynell ◽  
Claire A. McLellan ◽  
Lillian B. Hughes ◽  
Wenbo Wang ◽  
Tom E. Mates ◽  
...  

2005 ◽  
Vol 478 (1-2) ◽  
pp. 77-90 ◽  
Author(s):  
Randell Mills ◽  
Jayasree Sankar ◽  
Andreas Voigt ◽  
Jiliang He ◽  
Paresh Ray ◽  
...  

1993 ◽  
Vol 317 ◽  
Author(s):  
M.M. Waitew ◽  
S. Ismat Shah

ABSTRACTDiamond films were deposited in a microwave plasma chemical vapor deposition (MPCVD) system on Ta substrates using a mixture of hydrogen and methane gases. The films were grown for varying lengths of time to provide samples with no diamond growth to a continuous diamond film. These films were analyzed using X-ray photoelectron spectroscopy (XPS) in order to understand the time dependent interactions between the substrate and the incoming carbon flux. Photoelectron peaks in the Ta 4f, C Is and Ols regions have been analyzed. In the initial stages of growth, a layer of carbide forms on the substrate. As the substrate becomes supersaturated with carbon, graphite starts to form on the surface. A diamond peak begins to appear after about 30 Minutes of deposition.


1997 ◽  
Vol 12 (10) ◽  
pp. 2686-2698 ◽  
Author(s):  
L. Fayette ◽  
B. Marcus ◽  
M. Mermoux ◽  
N. Rosman ◽  
L. Abello ◽  
...  

A sequential analysis of the growth of diamond films on silicon substrates in a microwave plasma assisted chemical vapor deposition (CVD) reactor has been performed by Raman spectroscopy. The plasma was switched off during measurements, but the substrate heating was maintained to minimize thermoelastic stresses. The detectivity of the present experimental setup has been estimated to be about a few tens of μmg/cm2. From such a technique, one expects to analyze different aspects of diamond growth on a non-diamond substrate. The evolution of the signals arising from the substrate shows that the scratching treatment used to increase the nucleation density induces an amorphization of the silicon surface. This surface is annealed during the first step of deposition. The evolution of the line shape of the spectra indicates that the non-diamond phases are mainly located in the grain boundaries. The variation of the integrated intensity of the Raman signals has been interpreted using a simple absorption model. A special emphasis was given to the evolution of internal stresses during deposition. It was verified that compressive stresses were generated when coalescence of crystals took place.


1994 ◽  
Vol 339 ◽  
Author(s):  
Michael Frenklach

ABSTRACTIt is becoming increasingly apparent that future progress in diamond chemical vapor deposition depends on deeper understanding of the underlying mechanism of surface processes. Substantial efforts toward this goal have led to several conclusions on which consensus is beginning to emerge. Among them are the mediating role of hydrogen atoms, generic features of the growth kinetics, thermodynamic stability of reconstructed (100) surfaces, and the insertion reaction of methyl into (100)-(2×l) dimers. Despite these efforts, an overall picture of diamond growth in terms of elementary processes is still lacking. In this paper, the current state of mechanistic understanding is reviewed, emphasizing common themes, and new results are presented. Among the latter are the effect of reaction reversibility on surface morphology, surface migration, and a new mechanism for diamond growth from acetylene.


1994 ◽  
Vol 9 (8) ◽  
pp. 2154-2163 ◽  
Author(s):  
K.J. Grannen ◽  
R.P.H. Chang

Microwave plasma-enhanced chemical vapor deposition of diamond films on silicon carbide and tungsten carbide (with 6% cobalt) surfaces using fluorocarbon gases has been demonstrated. No diamond powder pretreatment is necessary to grow these films with a (100) faceted surface morphology. The diamond films are characterized by scanning electron microscopy and Raman spectroscopy. The proposed nucleation and growth mechanism involves etching of the noncarbon component of the carbide by atomic fluorine to expose surface carbon atoms and diamond nucleation and growth on these exposed carbon atoms. Hydrogen is necessary in the growth process to limit the rapid etching of the carbide substrates by corrosive fluorine atoms.


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