Thick stress-free amorphous-tetrahedral carbon films with hardness near that of diamond

Friedmann, T. A.; Sullivan, John P.; Knapp, J. A.; Tallant, D. R.; Follstaedt, D. M.; Medlin, Douglas L.; Mirkarimi, Paul B.

doi:10.1063/1.120515

Cited by 298 publications

(122 citation statements)

References 14 publications

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“…Additionally, the second order Raman peak for silicon at ϳ960 cm −1 decreases with increasing annealing temperature, indicating increased absorption of the ta-C film, presumably from the increased threefold carbon content which has a higher absorption cross section for the Raman process. 5 The comparison between the NEXAFS spectra and the Raman spectra leads to important conclusions. First, because NEXAFS is a more surface-sensitive technique and Raman samples more of the bulk of the sample, the similar trends observed from both techniques suggest that the ta-C samples are being modified both at the surface and deeper into their bulk.…”

Section: Resultsmentioning

confidence: 99%

“…Since ta-C is a desirable material for MEMS, post-deposition stress relief is critical. With suitable control of film deposition, 100% stress relief ͑down to zero Ϯ10 MPa͒ can be achieved in these films by either thermal annealing 5,12 for a period of minutes at a temperature of ϳ650°C or laser annealing at higher temperatures for nanoseconds. 20 High-quality ta-C films can also be deposited using the filtered cathodic arc method.…”

Section: Introductionmentioning

confidence: 99%

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Thermal stability and rehybridization of carbon bonding in tetrahedral amorphous carbon

Grierson¹,

Sumant²,

Konicek

et al. 2010

Journal of Applied Physics

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We preform a quantitative investigation of the energetics of thermally induced sp 3 → sp 2 conversion of carboncarbon bonds in tetrahedral amorphous carbon (ta-C) films by using near edge x-ray absorption fine structure (NEXAFS) and Raman spectroscopy. We investigate the evolution of the bonding configuration in ta-C thin films subjected to high temperature annealing in flowing Argon gas using a rapid thermal annealing furnace over the range of 200-1000 ºC. We observe no substantial change in bonding structure below 600 ºC, and by 1000 ºC a significant increase in the sp 2 bonding in the film is observed. No oxygen bonding is detected in the NEXAFS spectra, but we do observe an isosbestic point, demonstrating that the thermally driven sp 3 → sp 2 conversion reaction occurs without passing through an intermediate transition state. This allows us to use NEAFS spectra of thermally annealed ta-C films to quantitatively determine that the activation energy for directly converting the sp 3 -bonded carbon to the sp We perform a quantitative investigation of the energetics of thermally induced sp 3 → sp 2 conversion of carbon-carbon bonds in tetrahedral amorphous carbon ͑ta-C͒ films by using near-edge x-ray absorption fine structure ͑NEXAFS͒ and Raman spectroscopy. We investigate the evolution of the bonding configuration in ta-C thin films subjected to high temperature annealing in flowing Argon gas using a rapid thermal annealing furnace over the range of 200-1000°C. We observe no substantial change in bonding structure below 600°C. Changes in the NEXAFS and Raman spectra start to appear above 600°C, and by 1000°C a significant increase in the sp 2 bonding in the film is observed. No oxygen bonding is detected in the NEXAFS spectra, but we do observe an isosbestic point, demonstrating that the thermally driven sp 3 → sp 2 conversion reaction occurs without passing through an intermediate transition state. This allows us to use NEXAFS spectra of thermally annealed ta-C films to quantitatively determine that the activation energy for directly converting the sp 3 -bonded carbon to the sp 2 -bonded configuration is 3.5Ϯ 0.9 eV.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Thermal stability and rehybridization of carbon bonding in tetrahedral amorphous carbon

Grierson¹,

Sumant²,

Konicek

et al. 2010

Journal of Applied Physics

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“…A constant loading rate of 30 mN/s was applied. Nanohardness and Young's modulus values were measured as a function of indentation depth, and were determined using a modified Oliver-Pharr model [49].…”

Section: Experimental Methodsmentioning

confidence: 99%

Electrochemical and antimicrobial properties of diamondlike carbon-metal composite films

Morrison

Buchanan

Liaw

et al. 2006

Diamond and Related Materials

134

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Implants containing antimicrobial metals may reduce morbidity, mortality, and healthcare costs associated with medical device-related infections. We have deposited diamondlike carbonsilver (DLC-Ag), diamondlike carbon-platinum (DLC-Pt), and diamondlike carbon-silverplatinum (DLC-AgPt) thin films using a multicomponent target pulsed laser deposition process.Transmission electron microscopy of the DLC-silver and DLC-platinum composite films revealed that the silver and platinum self-assemble into nanoparticle arrays within the diamondlike carbon matrix. The diamondlike carbon-silver film possesses hardness and Young's modulus values of 37 GPa and 331 GPa, respectively. The diamondlike carbon-metal composite films exhibited passive behavior at open-circuit potentials. Low corrosion rates were observed during testing in a phosphate-buffered saline (PBS) electrolyte. In addition, the diamondlike carbon-metal composite films were found to be immune to localized corrosion below 1000 mV (SCE). DLC-silver-platinum films demonstrated exceptional antimicrobial properties against Staphylococcus bacteria. It is believed that a galvanic couple forms between platinum and silver, which accelerates silver ion release and provides more robust antimicrobial activity.Diamondlike carbon-silver-platinum films may provide unique biological functionalities and improved lifetimes for cardiovascular, orthopaedic, biosensor, and implantable microelectromechanical systems.

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“…However, DLC is an amorphous material with K=0.2 -3.5 W/mK at RT [25], which is a very low value Graphene-on-Diamond: Carbon sp 2 -on-sp 3 Technology, UCR and ANL, Nano Letters (2012) 6 even compared to SiO 2. Depending on H content, as-deposited DLC films have high internal stress, which needs to be released by annealing at higher T~600 o C [26]. These facts provide strong motivations for the search of other carbon materials, which can be used as substrates for graphene devices.…”

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confidence: 99%

Graphene-on-Diamond Devices with Increased Current-Carrying Capacity: Carbon sp²-on-sp³ Technology

et al. 2012

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Graphene demonstrated potential for practical applications owing to its excellent electronic and thermal properties. Typical graphene field-effect transistors and interconnects built on conventional SiO 2 /Si substrates reveal the breakdown current density on the order of 1 μA/ nm 2 (i.e., 10 8 A/cm 2 ), which is ∼100× larger than the fundamental limit for the metals but still smaller than the maximum achieved in carbon nanotubes. We show that by replacing SiO 2 with synthetic diamond, one can substantially increase the current-carrying capacity of graphene to as high as ∼18 μA/nm 2 even at ambient conditions. Our results indicate that graphene's currentinduced breakdown is thermally activated. We also found that the current carrying capacity of graphene can be improved not only on the single-crystal diamond substrates but also on an inexpensive ultrananocrystalline diamond, which can be produced in a process compatible with a conventional Si technology. The latter was attributed to the decreased thermal resistance of the ultrananocrystalline diamond layer at elevated temperatures. The obtained results are important for graphene's applications in high-frequency transistors, interconnects, and transparent electrodes and can lead to the new planar sp 2 -on-sp 3 carbon-on-carbon technology.

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Thick stress-free amorphous-tetrahedral carbon films with hardness near that of diamond

Cited by 298 publications

References 14 publications

Thermal stability and rehybridization of carbon bonding in tetrahedral amorphous carbon

Thermal stability and rehybridization of carbon bonding in tetrahedral amorphous carbon

Electrochemical and antimicrobial properties of diamondlike carbon-metal composite films

Graphene-on-Diamond Devices with Increased Current-Carrying Capacity: Carbon sp²-on-sp³ Technology

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Thick stress-free amorphous-tetrahedral carbon films with hardness near that of diamond

Cited by 298 publications

References 14 publications

Thermal stability and rehybridization of carbon bonding in tetrahedral amorphous carbon

Thermal stability and rehybridization of carbon bonding in tetrahedral amorphous carbon

Electrochemical and antimicrobial properties of diamondlike carbon-metal composite films

Graphene-on-Diamond Devices with Increased Current-Carrying Capacity: Carbon sp2-on-sp3 Technology

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Product

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Graphene-on-Diamond Devices with Increased Current-Carrying Capacity: Carbon sp²-on-sp³ Technology