The role of C2 in nanocrystalline diamond growth

Rabeau, James R.; Fan, Yong; John, P.; Wilson, J.I.B.

doi:10.1063/1.1810637

Cited by 94 publications

(63 citation statements)

References 46 publications

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“…However, their conclusion was based on the fact that for both noble gas containing plasmas the growth rates were similar. This along with the fact that nanocrystalline diamond film was grown in the presence of the He plasma, which contained undetectable C 2 levels, led them to the conclusion that C 2 dimer is not the key growth species [7]. Also, there was no correlation between the amount of C 2 and the growth rate in the Ar plasma [7].…”

Section: Introductionmentioning

confidence: 99%

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Synthesis and mechanical wear studies of ultra smooth nanostructured diamond (USND) coatings deposited by microwave plasma chemical vapor deposition with He/H2/CH4/N2 mixtures

Chowdhury

Borham

Catledge

et al. 2008

Diamond and Related Materials

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Ultra smooth nanostructured diamond (USND) coatings were deposited by microwave plasma chemical vapor deposition (MPCVD) technique using He/H 2 /CH 4 /N 2 gas mixture. The RMS surface roughness as low as 4 nm (2 micron square area) and grain size of 5-6 nm diamond coatings were achieved on medical grade titanium alloy. Previously it was demonstrated that the C 2 species in the plasma is responsible for the production of nanocrystalline diamond coatings in the Ar/H 2 /CH 4 gas mixture. In this work we have found that CN species is responsible for the production of USND coatings in He/H 2 /CH 4 /N 2 plasma. It was found that diamond coatings deposited with higher CN species concentration (normalized by Balmer H α line) in the plasma produced smoother and highly nanostructured diamond coatings. The correlation between CN/H α ratios with the coating roughness and grain size were also confirmed with different set of gas flows/plasma parameters. It is suggested that the presence of CN species could be responsible for producing nanocrystallinity in the growth of USND coatings using He/H 2 /CH 4 /N 2 gas mixture. The RMS roughness of 4 nm and grain size of 5-6 nm were calculated from the deposited diamond coatings using the gas mixture which produced the highest CN/H α species in the plasma. Wear tests were performed on the OrthoPOD ® , a six station pin-on-disk apparatus with ultra-high molecular weight polyethylene (UHMWPE) pins articulating on USND disks and CoCrMo alloy disk. Wear of the UHMWPE was found to be lower for the polyethylene on USND than that of polyethylene on CoCrMo alloy.

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Section: Introductionmentioning

confidence: 99%

“…However, later research was aimed at determining whether C 2 dimer was responsible for nanocrystalline diamond. Rabeau et al [7] grew nanocrystalline diamond films in Ar/H 2 /CH 4 and He/H 2 / CH 4 plasmas. They detected via OES strong C 2 emission in the Ar plasma, yet in the He plasma C 2 could not be detected.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and mechanical wear studies of ultra smooth nanostructured diamond (USND) coatings deposited by microwave plasma chemical vapor deposition with He/H2/CH4/N2 mixtures

Chowdhury

Borham

Catledge

et al. 2008

Diamond and Related Materials

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“…By applying DFT and tight binding (TB) DFT calculations, the C 2 radical when stuck to the diamond (100) surface was predicted to play a major role in the re-nucleation during UNCD growth, i.e., the formation of new diamond nuclei that evolve into diamond crystallites [112,113]. The latter was, however, disproved by Rabeau et al [60], as mentioned above. Besides the C 2 radical, also the methyl radical has been investigated extensively by means of DFT, that is, the carbon incorporation through CH 3 into dimers of the diamond (100) surface [108,109].…”

Section: Detailed Atomistic Simulations Of Nanostructure Growth Procementioning

confidence: 79%

“…One of the most striking findings considering the gas phase chemistry during diamond growth was accomplished by means of optical emission spectroscopy and cavity ring-down spectroscopy [60]. Indeed, Rabeau et al proved that the growth of both UNCD and NCD is independent of the C 2 radical, which was until then believed to be the major growth species of PE-CVD diamond [61].…”

Section: Modeling the Plasma Chemistry For The Growth Of Nanostructurmentioning

confidence: 99%

“…In order to unravel the growth mechanisms of UNCD and NCD, correlations between the composition of the plasma close to the surface and the resulting film properties have been considered [58][59][60]. One of the most striking findings considering the gas phase chemistry during diamond growth was accomplished by means of optical emission spectroscopy and cavity ring-down spectroscopy [60].…”

Section: Modeling the Plasma Chemistry For The Growth Of Nanostructurmentioning

confidence: 99%

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Computer modelling of the plasma chemistry and plasma-based growth mechanisms for nanostructured materials

Bogaerts¹,

Eckert²,

Mao³

et al. 2011

J. Phys. D: Appl. Phys.

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In this review paper, an overview is given of different modeling efforts for plasmas used for the formation and growth of nanostructured materials. This includes both the plasma chemistry, providing information on the precursors for nanostructure formation, as well as the growth processes itself. We limit ourselves to carbon (and silicon) nanostructures. Examples of the plasma modeling comprise nanoparticle formation in silane and hydrocarbon plasmas, as well as the plasma chemistry giving rise to carbon nanostructure formation, such as (ultra)nanocrystalline diamond ((U)NCD) and carbon nanotubes (CNTs). The second part of the paper deals with the simulation of the (plasma-based) growth mechanisms of the same carbon nanostructures, i.e., (U)NCD and CNTs, both by mechanistic modeling and detailed atomistic simulations. IntroductionLow temperature plasmas are playing an increasingly important role for the formation and growth of nanostructures and nanostructured materials (e.g., [1][2][3][4][5][6][7]). To improve the performance of these plasma growth processes, a good insight is desired in the plasma and in the interaction with the growing nanostructures. This insight can be obtained by experimental research, but the latter is not always straightforward, in view of the small dimensions of the nanomaterials and the possible disturbance of the plasma characteristics, e.g., when introducing a probe. Therefore, computer simulations can be very useful to assist in the experimental developments.In the present paper, we will give an overview of different modeling efforts that have been presented in the literature for plasmas used for nanostructure formation. This includes two different aspects. First, a thorough understanding of the plasma behavior is needed. This comprises background gas flow and heating (i.e., fluid dynamics), gas breakdown, transport and heating of the electrons and the so-called heavy particles, as well as the plasma chemistry, i.e., creation and destruction of the various plasma species by chemical reactions. Modeling of the plasma chemistry can give indications on which species are important precursors for the growth of nanostructured materials and how the plasma operating conditions can be tuned to optimize the growth process. Therefore, in this paper we will mainly focus on the plasma chemistry modeling. Several plasma modeling approaches exist in literature, such as analytical models, zero-dimensional (0D) chemical kinetics simulations, fluid models (describing the chemical kinetics as well as fluid dynamics), solving the Boltzmann transport equation, Monte Carlo (MC) and particle-in-cell (PIC)-MC simulations, as well as hybrid methods, combining the above (e.g., MC + fluid) models. For describing the plasma chemistry, the 0D chemical kinetics approach is often applied, as it can take into account a large number of different species and reactions without too much computational effort. However, it assumes a spatially uniform plasma composition and does not consider transport of the plasm...

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Plasma‐Enhanced Chemical Vapor Deposition

Lau

2016

Medical Coatings and Deposition Technologies

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The role of C2 in nanocrystalline diamond growth

Cited by 94 publications

References 46 publications

Synthesis and mechanical wear studies of ultra smooth nanostructured diamond (USND) coatings deposited by microwave plasma chemical vapor deposition with He/H2/CH4/N2 mixtures

Synthesis and mechanical wear studies of ultra smooth nanostructured diamond (USND) coatings deposited by microwave plasma chemical vapor deposition with He/H2/CH4/N2 mixtures

Computer modelling of the plasma chemistry and plasma-based growth mechanisms for nanostructured materials

Plasma‐Enhanced Chemical Vapor Deposition

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