Unravelling aspects of the gas phase chemistry involved in diamond chemical vapour deposition

Ashfold, Michael N. R.; May, Paul; Petherbridge, James R.; Rosser, KN; Smith, James A.; Mankelevich, Yu. A.; Suetin, N. V.

doi:10.1039/b104265n

Cited by 85 publications

(68 citation statements)

References 54 publications

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“…From a more applied point of view, acetylene is present in a number of processes of industrial interest: hot-filament-activated C 2 H 2 -H 2 gas mixtures are used to grow diamond carbon surfaces [7][8][9] or carbon nanotubes. [10] It is known that acetylene also plays a role as an intermediate species in the process of soot formation often observed in combustion research [11,12].…”

Section: Introductionmentioning

confidence: 99%

Linewidths of C2H2 perturbed by H2: experiments and calculations from an ab initio potential

Thibault

Corretja

Viel

et al. 2008

Phys. Chem. Chem. Phys.

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In this work we present a theoretical and experimental study of the acetylene -hydrogen system.A potential surface considering rigid monomers has been obtained by ab initio quantum chemistry methods. This 4-dimensional potential is further employed to compute using the close-clouping approach and the coupled-states approximation pressure broadening coefficients of C 2 H 2 isotropic Raman Q lines over a temperature range of 77 to 2000 K. Experimental data for the acetylene ν 2 Raman lines broadened by molecular hydrogen are obtained using stimulated Raman spectroscopy.The comparison at 143 K of theoretical values with experimental data is promising. Approximations to increase computational efficiency are proposed. *

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Section: Introductionmentioning

confidence: 99%

Linewidths of C2H2 perturbed by H2: experiments and calculations from an ab initio potential

Thibault

Corretja

Viel

et al. 2008

Phys. Chem. Chem. Phys.

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“…2000 K, which is considered to be representative of the gas temperature of a 51% CH 4 /49% CO 2 plasma in low power (<3 kW) microwave CVD chambers at $20 Torr, within the region from which gas was sampled during MBMS measurements. 36 2. The neglect of any electron impact dissociation, ionic reactions or surface chemistry.…”

Section: (B) Optical Emission Spectroscopymentioning

confidence: 99%

“…To mimic experiment, therefore, it is necessary to run the simulation for a finite (user selected) time, t. The calculations reported here employ t ¼ 5 s. This time was previously found to give the best agreement with MBMS measured trends in CO 2 /CH 4 plasma species counts. 36 Calculations were run repeatedly in order to determine plots of species mole fraction as functions of gas mixing ratio. The film grown at the lower T sub , using an H 2 S addition of 100 ppm ( Fig.…”

Section: (B) Optical Emission Spectroscopymentioning

confidence: 99%

Sulfur addition to microwave activated CH4/CO2 gas mixtures used for diamond CVD: growth studies and gas phase investigations

Petherbridge

May

Crichton

et al. 2002

Phys. Chem. Chem. Phys.

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Microwave plasma chemical vapour deposition (MPCVD) has been used to deposit diamond films with H 2 S additions of 0-5000 ppm to a 51% CH 4 /49% CO 2 plasma, with growth carried out for two different substrate temperatures (620 and 900 C). Film morphology, growth rate and quality are all observed to deteriorate with increased H 2 S addition, as investigated by scanning electron microscopy (SEM) and laser Raman spectroscopy (LRS). H 2 S addition also appears to alter the resistivity of films, as measured by the four-point probe method, however X-ray photoelectron spectroscopy (XPS) revealed little incorporation of sulfur. The plasma chemistry leading to film deposition has been investigated using optical emission spectroscopy (OES), in which H 2 S addition leads to a reduction in C 2 * and CH* intensities. Molecular beam mass spectrometry (MBMS) measurements have detected a build-up in CS, CS 2 , SO and SO 2 concentrations with addition of H 2 S. Experimental results have been compared to CHEMKIN simulations of plasma chemistry and S-incorporation has been investigated in terms of the product of CHEMKIN predicted mole fractions of CH 3 and CS, [CH 3

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“…Electron-driven chemistry of acetylene is important in key semiconductor and nanotechnology applications, e.g, acetylene is commonly used for carbon film deposition [1,2]. It is also of interest in astrophysics, e.g., acetylene has been identified in Titan's atmosphere [3][4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Ion-momentum imaging of dissociative-electron-attachment dynamics in acetylene

et al. 2014

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We present experimental results for dissociative electron attachment to acetylene near the 3 eV 2 Π g resonance. In particular, we use an ion-momentum imaging technique to investigate the dissociation channel leading to C 2 H − fragments. From our measured ion-momentum results we extract fragment kinetic energy and angular distributions. We directly observe a significant dissociation bending dynamic associated with the formation of the transitory negative ion. In modeling this bending dynamic with ab initio electronic structure and fixed-nuclei scattering calculations we obtain good agreement with the experiment.

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Unravelling aspects of the gas phase chemistry involved in diamond chemical vapour deposition

Cited by 85 publications

References 54 publications

Linewidths of C2H2 perturbed by H2: experiments and calculations from an ab initio potential

Linewidths of C2H2 perturbed by H2: experiments and calculations from an ab initio potential

Sulfur addition to microwave activated CH4/CO2 gas mixtures used for diamond CVD: growth studies and gas phase investigations

Ion-momentum imaging of dissociative-electron-attachment dynamics in acetylene

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