Effects of argon and oxygen addition to the CH4-H2 feed gas on diamond synthesis by microwave plasma enhanced chemical vapor deposition

Han, Young‐Soo; Kim, Yoon-Kee; Lee, Jun Young

doi:10.1016/s0040-6090(97)00339-8

Cited by 29 publications

(12 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Concerning the deposition of carbon, we observe a transition from a chemistry dominated by CH 3 when methane is used, to one governed by C 2 when highly diluted methane in argon is employed. This finding is coherent with recent experimental observations indicating that high fractions of argon in H 2 /Ar/CH 4 plasmas result in an increase in the C 2 concentration [20,21]. While the role of the methyl radical as a growth specie is known, only recently C 2 has been suggested as a precursor of diamond-like films in CH 4 /Ar and C 60 /Ar plasmas [3,8,22].…”

Section: Resultssupporting

confidence: 90%

Ar doping of CH4 plasmas for carbon film deposition

et al. 2000

View full text Add to dashboard Cite

We have modeled the gas-phase chemistry of a typical radio frequency CH4/Ar plasma used for the deposition of diamond and diamond-like carbon films. Our simulations show that the most abundant carbon containing radical is CH3 in pure methane discharges, but it is the carbon dimer C2 in discharges of methane highly diluted by argon. Thus we propose that the gaseous precursor of the film is CH3 in methane plasmas, and C2 in CH4/Ar plasmas. This proposal resolves outstanding discrepancies and is consistent with recent experiments demonstrating the deposition of diamond from hydrogen deficient plasmas.

show abstract

Section: Resultssupporting

confidence: 90%

Ar doping of CH4 plasmas for carbon film deposition

et al. 2000

View full text Add to dashboard Cite

show abstract

“…Microwave (MW) plasma-enhanced chemical vapor deposition (PE CVD) is a favored route for growing diamond films from gas mixtures comprising hydrogen and a small amount of a hydrocarbon precursor (typically methane). 1−4 Adding Ar to the CH 4 /H 2 plasma has variously been reported to influence the film growth rate, 5,6 its surface morphology, and the average crystallite size. 7−9 Synthesis of (ultra)nanocrystalline diamond films has even been reported from MW-activated gas mixtures involving just CH 4 and Ar as process gases.…”

Section: Introductionmentioning

confidence: 99%

Combined Spatially Resolved Optical Emission Imaging and Modeling Studies of Microwave-Activated H₂/Ar and H₂/Kr Plasmas Operating at Powers and Pressures Relevant for Diamond Chemical Vapor Deposition

et al. 2019

View full text Add to dashboard Cite

Microwave (MW) activated H2/Ar (and H2/Kr) plasmas operating under powers and pressures relevant to diamond chemical vapor deposition have been investigated experimentally and by 2-D modeling. The experiments return spatially and wavelength resolved optical emission spectra of electronically excited H2 molecules and H and Ar(/Kr) atoms for a range of H2/noble gas mixing ratios. The self-consistent 2-D(r, z) modeling of different H2/Ar gas mixtures includes calculations of the MW electromagnetic fields, the plasma chemistry and electron kinetics, heat and species transfer and gas−surface interactions. Comparison with the trends revealed by the spatially resolved optical emission measurements and their variations with changes in process conditions help guide identification and refinement of the dominant plasma (and plasma emission) generation mechanisms and the more important ArH, ArH2 and HH2 coupling reactions. Noble gas addition is shown to encourage radial expansion of the plasma, and thus to improve the uniformity of the H atom concentration and the gas temperature just above the substrate. Noble gas addition in the current experiments is also found to enhance (unwanted) sputtering of the copper base plate of the reactor; the experimentally observed increase in gas phase Cu* emission is shown to correlate with the near substrate ArH + (and KrH +) ion concentrations returned by the modelling, rather than with the relatively more abundant H3 + (and H3O +) ions.

show abstract

“…In this study we focus our attention to oxygen impurity in diamond. Previous investigations showed [1][2][3][4] that addition of oxygen precursors in the diamond chemical vapor deposition (CVD) synthesis process improves the growth speed and the quality of diamond. The formation of diamond from carbon and hydrogen precursors in the presence of oxygen occurs when the number of oxygen and carbon atoms is about the same according to the C, H, O phase diagram 5 .…”

Section: Introductionmentioning

confidence: 99%

“…It has been not yet understood whether these ESR and PL centers have no common origin or they have common origin but the spinpolarization effect in OV center is negligible for other reasons. The other oxygen-related OVH ESR center has S = 1/2 spin state with a characteristic 1 H hyperfine signal of A || =±13.6(1) MHz, A ⊥ =∓9.0(1) MHz and gtensor of g || =2.0034(1), g ⊥ =2.0029 (1) 7 . This ESR center was very analogous with the negatively charged NVH(−) ESR center 15 , thus it was proposed that the OVH ESR center should originate from the neutral OVH(0) defect because these two defects are isovalent.…”

Section: Introductionmentioning

confidence: 99%

“…Diamonds synthesized in Na 2 CO 3 −CO 2 −H 2 O−C filament with the same temperature and pressure conditions a new S = 1/2 ESR center was found that was labeled as VOH 27 . This ESR center was fitted with g || =2.0023(1), g ⊥ =2.0030 (1), and A || 35(1) MHz, A ⊥ =32(1) MHz spinHamiltonian parameters where the hyperfine coupling originates from an I = 1/2 nuclear spin with ≈100% abundance that was associated with a single 1 H 27 . This ESR center clearly differs from the one measured in CVD samples which is labeled as OVH 7 .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Characterization of oxygen defects in diamond by means of density functional theory calculations

Thiering¹,

Gali²

2016

Phys. Rev. B

View full text Add to dashboard Cite

Point defects in diamond are of high interest as candidates for realizing solid state quantum bits, bioimaging agents, or ultrasensitive electric or magnetic field sensors. Various artificial diamond synthesis methods should introduce oxygen contamination in diamond, however, the incorporation of oxygen into diamond crystal and the nature of oxygen-related point defects are largely unknown. Oxygen may be potentially interesting as a source of quantum bits or it may interact with other point defects which are well established solid state qubits. Here we employ plane-wave supercell calculations within density functional theory, in order to characterize the electronic and magneto-optical properties of various oxygen-related defects. Beside the trivial single interstitial and substitutional oxygen defects we also consider their complexes with vacancies and hydrogen atoms. We find that oxygen defects are mostly electrically active and introduce highly correlated orbitals that pose a challenge for density functional theory modeling. Nevertheless, we are able to identify the fingerprints of substitutional oxygen defect, the oxygen-vacancy and oxygen-vacancy-hydrogen complexes in the electron paramagnetic resonance spectrum. We demonstrate that first principles calculations can predict the motional averaging of the electron paramagnetic resonance spectrum of defects that are subject to Jahn-Teller distortion. We show that the high-spin neutral oxygen-vacancy defect exhibits very fast non-radiative decay from its optical excited state that might hinder to apply it as a qubit.

show abstract

Effects of argon and oxygen addition to the CH4-H2 feed gas on diamond synthesis by microwave plasma enhanced chemical vapor deposition

Cited by 29 publications

References 25 publications

Ar doping of CH4 plasmas for carbon film deposition

Ar doping of CH4 plasmas for carbon film deposition

Combined Spatially Resolved Optical Emission Imaging and Modeling Studies of Microwave-Activated H₂/Ar and H₂/Kr Plasmas Operating at Powers and Pressures Relevant for Diamond Chemical Vapor Deposition

Characterization of oxygen defects in diamond by means of density functional theory calculations

Contact Info

Product

Resources

About

Effects of argon and oxygen addition to the CH4-H2 feed gas on diamond synthesis by microwave plasma enhanced chemical vapor deposition

Cited by 29 publications

References 25 publications

Ar doping of CH4 plasmas for carbon film deposition

Ar doping of CH4 plasmas for carbon film deposition

Combined Spatially Resolved Optical Emission Imaging and Modeling Studies of Microwave-Activated H2/Ar and H2/Kr Plasmas Operating at Powers and Pressures Relevant for Diamond Chemical Vapor Deposition

Characterization of oxygen defects in diamond by means of density functional theory calculations

Contact Info

Product

Resources

About

Combined Spatially Resolved Optical Emission Imaging and Modeling Studies of Microwave-Activated H₂/Ar and H₂/Kr Plasmas Operating at Powers and Pressures Relevant for Diamond Chemical Vapor Deposition