Enhanced deposition rate of polycrystalline CVD diamond at high microwave power densities

Bolshakov, A. P.; Ralchenko, V.G.; Yurov, V. Yu.; Shu, Guoyang; Bushuev, E.V.; Хомич, А. А.; Ashkinazi, E. E.; Sovyk, D. N.; Antonova, I.A.; Savin, Sergey; Voronov, V. V.; Shevchenko, Mikhail; Dai, Bing; Zhu, Jiaqi

doi:10.1016/j.diamond.2019.107466

Cited by 24 publications

(13 citation statements)

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“…Figure (b) shows the I em (C 2 (d)) and I em (H β ) intensities measured at the respective z m values; the former increases steeply with p , while the latter changes little. Figure (c) compares the p -dependent I em (C 2 (d))/ I em (H β ) ratios (henceforth R (C 2 (d)/H β )) measured both in the present work and by Bolshakov et al, with the {C 2 (d)}/{H( n = 3)} ratios predicted by the current 2D modeling.…”

Section: Resultssupporting

confidence: 53%

“…We do not reprise the same analytical procedures (and the similar related challenges) for correctly determining T e but concentrate on exploring the behavior of C 2 (d) and C 2 (C) species and their production and loss mechanisms and explaining the observed trends in R (C/d). Having established the necessary plasma chemistry and physics, we then investigate plasma constriction effects at higher ( p > 300 Torr) pressures, experimentally and theoretically, by tracing trends in C 2 (d) and H Balmer emission intensities and by reference to recent observations in a bell-jar-type MWPACVD reactor …”

Section: Resultsmentioning

confidence: 99%

“…Emissions from C 2 radicals, particularly via the d 3 Π g –a 3 Π u (Swan band) transition, are also ubiquitous in MWPA C/H (and C/H/Ar and C/H/O) gas mixtures used for diamond CVD. ,,,− The present study applies OE imaging methods for two different C 2 emissions, the much-studied d–a Swan band system centered at wavelength λ ≈ 515 nm and the C 1 Π g –A 1 Π u Deslandres–D’Azambuja transition at λ ≈ 385 nm as functions of processing conditions. The d and C states of C 2 have significantly different energies (2.48 and 4.25 eV, respectively, defined relative to the ground (X) state).…”

Section: Introductionmentioning

confidence: 99%

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Imaging and Modeling C₂ Radical Emissions from Microwave Plasma-Activated Methane/Hydrogen Gas Mixtures: Contributions from Chemiluminescent Reactions and Investigations of Higher-Pressure Effects and Plasma Constriction

et al. 2021

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Wavelength and spatially resolved imaging and 2D plasma chemical modeling methods have been used to study the emission from electronically excited C2 radicals in microwave-activated dilute methane/hydrogen gas mixtures under processing conditions relevant to the chemical vapor deposition (CVD) of diamond. Obvious differences in the spatial distributions of the much-studied C2(d3Πg–a3Πu) Swan band emission and the little-studied, higher-energy C2(C1Πg–A1Πu) emission are rationalized by invoking a chemiluminescent (CL) reactive source, most probably involving collisions between H atoms and C2H radicals, that acts in tandem with the widely recognized electron impact excitation source term. The CL source is relatively much more important for forming C2(d) state radicals and is deduced to account for >40% of C2(d) production in the hot plasma core under base operating conditions, which should encourage caution when estimating electron or gas temperatures from C2 Swan band emission measurements. Studies at higher pressures (p ≈ 400 Torr) offer new insights into the plasma constriction that hampers efforts to achieve higher diamond CVD rates by using higher processing pressures. Plasma constriction is proposed as being inevitable in regions where the local electron density (n e) exceeds some critical value (n ec) and electron–electron collisions enhance the rates of H2 dissociation, H-atom excitation, and related associative ionization processes relative to those prevailing in the neighboring nonconstricted plasma region. The 2D modeling identifies a further challenge to high-p operation. The radial uniformities of the CH3 radical and H-atom concentrations above the growing diamond surface both decline with increasing p, which are likely to manifest as less spatially uniform diamond growth (in terms of both rate and quality).

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Section: Resultssupporting

confidence: 53%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Imaging and Modeling C₂ Radical Emissions from Microwave Plasma-Activated Methane/Hydrogen Gas Mixtures: Contributions from Chemiluminescent Reactions and Investigations of Higher-Pressure Effects and Plasma Constriction

et al. 2021

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“…Such PCD material can be synthesized with chemical vapor deposition (CVD) technique either directly on the substrate of the choice, or on the carrier substrate, which is chemically removed after the growth [22][23][24]. The CVD technique allows the formation of large-area layers of high-quality PCD material [21,23].…”

Section: Introductionmentioning

confidence: 99%

Effect of Substrate Holder Design on Stress and Uniformity of Large-Area Polycrystalline Diamond Films Grown by Microwave Plasma-Assisted CVD

et al. 2020

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In this work, the substrate holders of three principal geometries (flat, pocket, and pedestal) were designed based on E-field simulations. They were fabricated and then tested in microwave plasma-assisted chemical vapor deposition process with the purpose of the homogeneous growth of 100-μm-thick, low-stress polycrystalline diamond film over 2-inch Si substrates with a thickness of 0.35 mm. The effectiveness of each holder design was estimated by the criteria of the PCD film quality, its homogeneity, stress, and the curvature of the resulting “diamond-on-Si” plates. The structure and phase composition of the synthesized samples were studied with scanning electron microscopy and Raman spectroscopy, the curvature was measured using white light interferometry, and the thermal conductivity was measured using the laser flash technique. The proposed pedestal design of the substrate holder could reduce the stress of the thick PCD film down to 1.1–1.4 GPa, which resulted in an extremely low value of displacement for the resulting “diamond-on-Si” plate of Δh = 50 μm. The obtained results may be used for the improvement of already existing, and the design of the novel-type, MPCVD reactors aimed at the growth of large-area thick homogeneous PCD layers and plates for electronic applications.

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“…So for different industrial applications, they are not affordable. The necessity of diamond coated cutting tool with the same tool geometry is increasing to minimize the cost of the diamond tool [34][35][36]. The HFCVD coated diamond tool would be a better alternative.…”

Section: Introductionmentioning

confidence: 99%

Study of cutting force and tool wear during turning of aluminium with WC, PCD and HFCVD coated MCD tools

et al. 2020

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Enormous developmental work has been made in synthesis of metastable diamond by hot filament chemical vapor deposition (HFCVD) method. In this paper, micro-crystalline diamond (MCD) was deposited on WC–6 wt.% Co cutting tool inserts by HFCVD technique. The MCD coated tool was characterized by the scanning electron microscope (SEM), X-ray diffraction (XRD) and micro Raman spectroscopy (μ-RS). A comparison was made among the MCD tool, uncoated tungsten carbide (WC) tool and polycrystalline diamond (PCD) tool during the dry turning of rolled aluminum. The various major tests were conducted such as surface roughness, cutting force and tool wear, which were taken into consideration to establish a proper comparison among the advanced cutting tools. Surface roughness was measured during machining by Talysurf. The tool wear was studied by SEM after machining. The cutting forces were measured by Kistler 3D-dynamometer during the machining process. The test results indicate that, the CVD coated MCD tool and PCD tool produced almost similar results. But, the price of PCD tools are five times costlier than MCD tools. So, MCD tool would be a better alternative for machining of aluminium.

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Enhanced deposition rate of polycrystalline CVD diamond at high microwave power densities

Cited by 24 publications

References 50 publications

Imaging and Modeling C₂ Radical Emissions from Microwave Plasma-Activated Methane/Hydrogen Gas Mixtures: Contributions from Chemiluminescent Reactions and Investigations of Higher-Pressure Effects and Plasma Constriction

Imaging and Modeling C₂ Radical Emissions from Microwave Plasma-Activated Methane/Hydrogen Gas Mixtures: Contributions from Chemiluminescent Reactions and Investigations of Higher-Pressure Effects and Plasma Constriction

Effect of Substrate Holder Design on Stress and Uniformity of Large-Area Polycrystalline Diamond Films Grown by Microwave Plasma-Assisted CVD

Study of cutting force and tool wear during turning of aluminium with WC, PCD and HFCVD coated MCD tools

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Enhanced deposition rate of polycrystalline CVD diamond at high microwave power densities

Cited by 24 publications

References 50 publications

Imaging and Modeling C2 Radical Emissions from Microwave Plasma-Activated Methane/Hydrogen Gas Mixtures: Contributions from Chemiluminescent Reactions and Investigations of Higher-Pressure Effects and Plasma Constriction

Imaging and Modeling C2 Radical Emissions from Microwave Plasma-Activated Methane/Hydrogen Gas Mixtures: Contributions from Chemiluminescent Reactions and Investigations of Higher-Pressure Effects and Plasma Constriction

Effect of Substrate Holder Design on Stress and Uniformity of Large-Area Polycrystalline Diamond Films Grown by Microwave Plasma-Assisted CVD

Study of cutting force and tool wear during turning of aluminium with WC, PCD and HFCVD coated MCD tools

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Product

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Imaging and Modeling C₂ Radical Emissions from Microwave Plasma-Activated Methane/Hydrogen Gas Mixtures: Contributions from Chemiluminescent Reactions and Investigations of Higher-Pressure Effects and Plasma Constriction

Imaging and Modeling C₂ Radical Emissions from Microwave Plasma-Activated Methane/Hydrogen Gas Mixtures: Contributions from Chemiluminescent Reactions and Investigations of Higher-Pressure Effects and Plasma Constriction