Quantitative measurements of atomic hydrogen during the deposition of diamond-like carbon films

Donnelly, Kevin; Dowling, Denis P.; O’Brien, Timothy P.; O’Leary, Austin J.; Kelly, T.C.; Cheshire, R.; Al-Assadi, Khalid F.; Graham, W. G.; Morrow, Tom; Kornas, V.; Gathen, Volker Schulz-von der; Döbele, H. F.

doi:10.1016/0925-9635(94)05304-9

Cited by 5 publications

(3 citation statements)

References 2 publications

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“…Another two‐photon LIF technique following excitation at 205.1 nm can be used to detect high‐density H atoms at more than 10 13 cm −3 21, 30, 50, 52, 54, 63–66, 70, 76, 82, 94, 103–119. In this case, H(1s 2 S) is excited to H(3s 2 S) and H(3d 2 D J ) states and Balmer‐α emission at 656.3 nm is monitored.…”

Section: Experimental Techniques For Detecting H Atoms In the Gas mentioning

confidence: 99%

Production and Detection of H Atoms and Vibrationally Excited H₂ Molecules in CVD Processes

Umemoto¹

2010

Chemical Vapor Deposition

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Radical species, including atomic hydrogen, play an important role in the CVD process to prepare high-quality thin solid films. Detailed information on the absolute densities of these radicals under various conditions is needed in order to understand the chemical kinetics involved and to control the deposition processes. This article reviews the production mechanisms and the gasphase diagnostic techniques for H atoms in catalytic CVD (also called hot-wire CVD) and plasma-enhanced (PE)CVD processes. Experimentally determined absolute H-atom densities in typical CVD processes are compiled in a table. Under suitable conditions, the steady-state H-atom density can be increased up to 10 17 cm À3. Procedures for producing and detecting vibrationally excited H 2 molecules, which can be another active species in CVD processes, are also discussed.

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Section: Experimental Techniques For Detecting H Atoms In the Gas mentioning

confidence: 99%

Production and Detection of H Atoms and Vibrationally Excited H₂ Molecules in CVD Processes

Umemoto¹

2010

Chemical Vapor Deposition

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“…In low pressure environments the collisional quenching of the fluorescence signal can be determined 37,40 and the H LIF signal can be quantified by comparison to measurements in a calibration reactor where the H concentration is known. 29,31,32 At atmospheric pressure, however, quantification of the signal is hampered by collisional quenching of the fluorescence, which not only depends on temperature and pressure, but also on the nature of the collision partners. Since at atmospheric pressure many collisions will take place during the fluorescence lifetime and a multitude of different species is available to collide with, quantitative measurements are not attempted and the results therefore will be interpreted in a more qualitative way.…”

Section: Introductionmentioning

confidence: 99%

“…25 Experimental investigations on the surface role of H have been carried out by Ohl et al 26 and Butler and co-workers, 27 among others. Studies on atomic hydrogen in the gas phase of CVD systems have been carried out in a hot filament reactor by resonance enhanced multi-photon ionization 28 and two-photon laser induced fluorescence ͑LIF͒, 29,30 which technique has also been used in a rf plasma reactor 31,32 and a microwave reactor. 33 In the present work the two-dimensional laser induced fluorescence ͑2D-LIF͒ technique is applied to measure the distributions of atomic hydrogen and C 2 in the oxyacetylene flame during diamond growth.…”

Section: Introductionmentioning

confidence: 99%

Spatial distributions of atomic hydrogen and C2 in an oxyacetylene flame in relation to diamond growth

Klein-Douwel

Meulen

1998

Journal of Applied Physics

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Two-dimensional laser induced fluorescence measurements are applied to the chemical vapour deposition of diamond by an oxyacetylene flame to visualize the distributions of atomic hydrogen and C 2 in the gas phase during diamond growth. Experiments are carried out in both laminar and turbulent flames and reveal that atomic hydrogen is ubiquitous at and beyond the flame front. Its presence extends to well outside the diamond deposition region, whereas the C 2 distribution is limited to the flame front and the acetylene feather. The diamond layers obtained are characterized by optical as well as scanning electron microscopy and Raman spectroscopy. Clear relations are observed between the local variations in growth rate and quality of the diamond layer and the distribution of H and C 2 in the boundary layer just above the substrate. These relations agree with theoretical models describing their importance in ͑flame͒ deposition processes of diamond. Three separate regions can be discerned in the flame and the diamond layer, where the gas phase and diamond growth are predominantly governed by the flame source gases, the ambient atmosphere, and the interaction of both, respectively.

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Temperature mapping of reactive gas layer in thermal plasma chemical vapor deposition

Larjo

Walewski

Hernberg

1997

Journal of Applied Physics

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Two-dimensional temperature maps of reactive gas layers were produced using pulsed laser Rayleigh scattering thermometry. The measurements were made in conditions of diamond film chemical vapor deposition (CVD) using a thermal inductively coupled plasma. In these conditions, the reactive gas layer is typically a few millimeters thick and the temperature drops across the layer from 4000 K at the free stream boundary to about 1200 K at the substrate. The reactive layer exhibits strong chemical nonequilibrium. Rayleigh scattering was induced using a pulsed laser sheet at 532 nm wavelength. The scattered radiation was detected and calibrated with an intensified charge coupled device camera. Temperature maps and axial profiles obtained under parametric variation of the gas flow conditions demonstrate how the technique can be employed to measure the reactive layer thickness and its radial distribution across the substrate. The results demonstrate that imaging Rayleigh scattering thermometry can be employed as a nonintrusive diagnostic tool to obtain useful experimental information pertinent to the gas phase chemistry in diamond CVD under conditions of extremely large temperature gradients.

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Quantitative measurements of atomic hydrogen during the deposition of diamond-like carbon films

Cited by 5 publications

References 2 publications

Production and Detection of H Atoms and Vibrationally Excited H₂ Molecules in CVD Processes

Production and Detection of H Atoms and Vibrationally Excited H₂ Molecules in CVD Processes

Spatial distributions of atomic hydrogen and C2 in an oxyacetylene flame in relation to diamond growth

Temperature mapping of reactive gas layer in thermal plasma chemical vapor deposition

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Quantitative measurements of atomic hydrogen during the deposition of diamond-like carbon films

Cited by 5 publications

References 2 publications

Production and Detection of H Atoms and Vibrationally Excited H2 Molecules in CVD Processes

Production and Detection of H Atoms and Vibrationally Excited H2 Molecules in CVD Processes

Spatial distributions of atomic hydrogen and C2 in an oxyacetylene flame in relation to diamond growth

Temperature mapping of reactive gas layer in thermal plasma chemical vapor deposition

Contact Info

Product

Resources

About

Production and Detection of H Atoms and Vibrationally Excited H₂ Molecules in CVD Processes

Production and Detection of H Atoms and Vibrationally Excited H₂ Molecules in CVD Processes