Properties of amorphous diamond films prepared by a filtered cathodic arc

Lossy, R.; Pappas, David; Roy, R.; Doyle, J. P.; Cuomo, J. J.; Bruley, J.

doi:10.1063/1.359411

Cited by 130 publications

(47 citation statements)

References 41 publications

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“…On the other hand, density determinations via EELS rely on an effective electron mass, for which different values can be found in literature [7][8][9]. We will show how a correct fit of the plasmon peak and an appropriate choice of the effective mass can give good agreement with the XRR mean densities, thus validating the use of the quasi-free electron model to analyse the low loss spectrum.…”

Section: Introductionmentioning

confidence: 87%

Density and sp³ Content in Diamond-Like Carbon Films by X-ray Reflectivity and Electron Energy Loss Spectroscopy

et al. 1999

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Grazing angle x-ray reflectivity (XRR) is used to study density, thickness, internal layering and roughness of a variety of carbon samples, with and without hydrogen and nitrogen. The bulk mass density of optimised tetrahedral amorphous carbon (ta-C) is 3.26 g/cm2, for which Electron Energy Loss Spectroscopy (EELS) found a sp3 fraction of 85%. Combining XRR and EELS we benchmark the dependence of sp3 fraction on density for hydrogen-free carbons. Hydrogenated ta-C (ta-C:H) deposited by electron cyclotron wave resonance (ECWR) reactor from acetylene gas, has a density of 2.35 g/cm3, 75% sp3 and ∼30% hydrogen. These data provide a similar validation for density and sp3 EELS data for hydrogenated DLCs. XRR can also reveal internal layering in films, and indeed less dense layers may be found at the surface or interface of ta-C films, but no such layers are found in ta-C:H films.

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Section: Introductionmentioning

confidence: 87%

Density and sp³ Content in Diamond-Like Carbon Films by X-ray Reflectivity and Electron Energy Loss Spectroscopy

et al. 1999

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“…The virtual spectrum of each pyrocarbon can be compared to the isotropic-like virtual spectrum obtained from a graphite single crystal (100% sp 2 ) using the same process (i.e., with single crystals having random orientation). The sp 2 content of the pyrocarbon is subsequently calculated from more conventional calculation [15] and [16].…”

Section: Electron Energy Loss Spectroscopymentioning

confidence: 99%

Quantitative structural and textural assessment of laminar pyrocarbons through Raman spectroscopy, electron diffraction and few other techniques

Vallerot¹,

Bourrat²,

Mouchon³

et al. 2006

Carbon

161

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In pyrocarbon materials, the width of the Raman D band (FWHM D ) is very sensitive to low energy structural defects (e.g., disorientations of the graphene layers). The correlation between the two parameters, FWHM D and OA (as derived from selected area electron diffraction: SAED), has allowed to differentiate various pyrocarbons unambiguously. Furthermore, the optical properties of pyrocarbons, i.e., the extinction angle, the optical phase shift and the ordinary and extraordinary reflectance, have been accurately determined at 550 nm by means of the extinction curves method. These results are completed by in-plane and out-of-plane dielectric constant measurements by angular resolved EELS. Moreover, the hybridization degree of the carbon atoms has been assessed by the same technique. About 80% of the carbon atoms of the pyrocarbons have a sp 2 hybridization. The lack of pure sp 2 carbon atoms, as compared to graphite, might be explained by the presence of sp 3 -like line defects.

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“…Amorphous carbon films (a-C) that have more than 80% tetrahedral (sp 3 ) bonding are referred to as tetrahedral amorphous carbon (ta-C) [7,9,19], or sometimes even as "amorphous diamond." [20,21] There are large variations even within each class of materials, depending on the method and parameters of deposition. Diamond-like carbon films can be synthesized by argon sputter deposition using a graphite target [12,22] [6,16,20,21].…”

Section: Introductionmentioning

confidence: 99%

“…[20,21] There are large variations even within each class of materials, depending on the method and parameters of deposition. Diamond-like carbon films can be synthesized by argon sputter deposition using a graphite target [12,22] [6,16,20,21]. Research over the last years has identified filtered cathodic arc deposition as one of the promising techniques for hard carbon films thinner than 5 nm [28,29].…”

Section: Introductionmentioning

confidence: 99%

Ultrathin diamond-like carbon films deposited by filtered carbon vacuum arcs

Anders

Fong

Kulkarni

et al. 2001

IEEE Trans. Plasma Sci.

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Ultrathin (< 5 nm) hard carbon films are of great interest to the magnetic storage industry as the areal density approaches 100 Gbit/in 2 . These films are used as overcoats to protect the magnetic layers on disk media and the active elements of the read-write slider. Tetrahedral amorphous carbon films can be produced by filtered cathodic arc deposition, but the films will only be accepted by the storage industry only if the "macroparticle" issue has been solved. Better plasma filters have been developed over recent years. Emphasis is put on the promising twist filter system -a compact, open structure that operates with pulsed arcs and high magnetic field. Based on corrosion tests it is shown that the macroparticle reduction by the twist filter is satisfactory for this demanding application, while plasma throughput is very high. Ultrathin hard carbon films have been synthesized using Sfilter and twist filter systems. Film properties such as hardness, elastic modulus, wear, and corrosion resistance have been tested. Index Terms: diamond-like carbon, cathodic vacuum arc, macroparticle filtering, magnetic storage, carbon overcoats 3 I. INTRODUCTIONUltrathin (< 5 nm) hard carbon films are used as protective overcoats on hard disks and readwrite heads. The tribological properties of the head-disk interface are not only of mechanical but also of chemical nature: the overcoat should protect the magnetic layers against wear and corrosion [1, 2]. The areal density of information stored in disk drive products increased at an amazing rate of over 65% for many years rate, and continues to accelerate to even greater rates [3]. To accomplish this, the "magnetic spacing" between the magnetic layers of the disk and read/write sensor of the head must continue to decrease. The magnetic spacing includes the overcoats, lubrication, and the fly height. Thinner overcoats allow the read-write head to be closer to the magnetic layer of the disk, and hence, the size of individual bits on the disk to be smaller. As we work toward an areal density of 100 Gbit/in 2 , the magnetic spacing approaches the sub-10-nm regime (pseudo-contact recording) and overcoat thickness must shrink to 1-2 nm. Overcoats currently used are sputtered or ion-beam deposited diamond-like carbon films, typically doped with hydrogen or nitrogen. They cease to provide acceptable levels of corrosion protection when the film thickness is less than 5 nm.Overcoats need to be tough (hard and elastic), chemically inert, pinhole-free, and compatible with the lubricant. The challenge of ultrathin film synthesis is to make the films as thin as possible and still continuous, as opposed to an assembly of islands.Nucleation and growth of ultrathin films is a field of intense research. For carbon, it is well known that films that are rich in sp 3 (diamond) bonds should be grown in a kinetic mode at low temperature (less than 200°C, preferably room temperature), with film-forming carbon atoms or ions having an energy of about 100 eV. This energy is optimized for subplantat...

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Properties of amorphous diamond films prepared by a filtered cathodic arc

Cited by 130 publications

References 41 publications

Density and sp³ Content in Diamond-Like Carbon Films by X-ray Reflectivity and Electron Energy Loss Spectroscopy

Density and sp³ Content in Diamond-Like Carbon Films by X-ray Reflectivity and Electron Energy Loss Spectroscopy

Quantitative structural and textural assessment of laminar pyrocarbons through Raman spectroscopy, electron diffraction and few other techniques

Ultrathin diamond-like carbon films deposited by filtered carbon vacuum arcs

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Properties of amorphous diamond films prepared by a filtered cathodic arc

Cited by 130 publications

References 41 publications

Density and sp3 Content in Diamond-Like Carbon Films by X-ray Reflectivity and Electron Energy Loss Spectroscopy

Density and sp3 Content in Diamond-Like Carbon Films by X-ray Reflectivity and Electron Energy Loss Spectroscopy

Quantitative structural and textural assessment of laminar pyrocarbons through Raman spectroscopy, electron diffraction and few other techniques

Ultrathin diamond-like carbon films deposited by filtered carbon vacuum arcs

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Product

Resources

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Density and sp³ Content in Diamond-Like Carbon Films by X-ray Reflectivity and Electron Energy Loss Spectroscopy

Density and sp³ Content in Diamond-Like Carbon Films by X-ray Reflectivity and Electron Energy Loss Spectroscopy