HFCVD diamond grown with added nitrogen: film characterization and gas-phase composition studies

Afzal, A; Rego, C.A.; Ahmed, Waqar; Cherry, R.I.

doi:10.1016/s0925-9635(98)00148-4

Cited by 48 publications

(17 citation statements)

References 24 publications

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“…It has been proposed that higher levels of CN radicals reduce the CH 3 concentration and thus reduce the growth rate. 17,32 Moreover, other growth parameters can also influence the growth behavior of diamond films. Bohr et al 33 observed that there was decrease in the growth rate when increasing the N 2 concentration at low filament temperature in hot filament CVD process.…”

Section: Resultsmentioning

confidence: 99%

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Microstructural evolution of diamond films from CH4/H2/N2 plasma and their enhanced electrical properties

Sankaran

Tai

Lin

2015

Journal of Applied Physics

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The influence of N 2 concentration in CH 4 /H 2 /N 2 plasma on microstructural evolution and electrical properties of diamond films is systematically investigated. While the diamond films grown in CH 4 / H 2 plasma contain large diamond grains, for the diamond films grown using CH 4 /H 2 /(4%)N 2 plasma, the microstructure drastically changed, resulting in ultra-nanosized diamond grains with Fd3m structure and a 0 ¼ 0.356 nm, along with the formation of n-diamond (n-D), a metastable form of diamond with space group Fm3m and a 0 ¼ 0.356 nm, and i-carbon (i-C) clusters, the bcc structured carbon with a 0 ¼ 0.432 nm. In addition, these films contain wide grain boundaries containing amorphous carbon (a-C). The electron field emission (EFE) studies show the best EFE behavior for 4% N 2 films among the CH 4 /H 2 /N 2 grown diamond films. They possess the lowest turn-on field value of 14.3 V/lm and the highest EFE current density value of 0.37 mA/cm 2 at an applied field of 25.4 V/lm. The optical emission spectroscopy studies confirm that CN species are the major criterion to judge the changes in the microstructure of the films. It seems that the grain boundaries can provide electron conduction networks to transport efficiently the electrons to emission sites for field emission, as long as they have sufficient thickness. Whether the matrix nano-sized grains are 3C-diamond, n-D or i-C is immaterial. V C 2015 AIP Publishing LLC.

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Section: Resultsmentioning

confidence: 99%

“…Restated, the growth rate of the films is decreased when increasing the N 2 concentration in CH 4 /H 2 gas mixtures, which is wellsupported to the previous findings. 17,23,32 Fig. 3(a) shows the EFE plots of current density (J) versus applied field (E).…”

Section: Resultsmentioning

confidence: 99%

Microstructural evolution of diamond films from CH4/H2/N2 plasma and their enhanced electrical properties

Sankaran

Tai

Lin

2015

Journal of Applied Physics

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“…The growth rate dropped as the CN/H α ratios increased and it stayed constant with the increase of the CN concentrating in the plasma. Higher levels of CN radicals reduce the CH 3 concentration and thus reduce the growth rate [18]. Figure 3 shows the glancing angle XRD patterns for the nanostructured diamond films grown on Ti-6Al-4V alloy using the He/CH 4 /H 2 /N 2 feed gas mixture where CN/H α in the plasma is 7.6.…”

Section: Resultsmentioning

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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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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“…The orientation of the diamond grains is normally random, and the grain boundary compromises the extraordinary physical properties of diamond [14,16,17]. The major disadvantage of traditional MPCVD methods is that only low growth rates of ~ 1 μm for polycrystalline diamond [18][19][20][21] had been reached.…”

Section: Introductionmentioning

confidence: 99%

“…Nitrogen added to the gas chemistry also played significant role in enhancing the growth rate and promoting the formation of the {100} faces [6,7,15,20]. These studies led to the first fabrication of transparent, smooth single-crystal CVD diamond.…”

Section: Introductionmentioning

confidence: 99%

Developments in synthesis, characterization, and application of large, high-quality CVD single crystal diamond

Liang

Meng

Yan

et al. 2013

J. Superhard Mater.

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HFCVD diamond grown with added nitrogen: film characterization and gas-phase composition studies

Cited by 48 publications

References 24 publications

Microstructural evolution of diamond films from CH4/H2/N2 plasma and their enhanced electrical properties

Microstructural evolution of diamond films from CH4/H2/N2 plasma and their enhanced electrical properties

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

Developments in synthesis, characterization, and application of large, high-quality CVD single crystal diamond

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