Comparison of Energetic Carbon Deposition Processes for Use As Ultra-Thin Disk Overcoats

Author(s):  
Richard L. White ◽  
Bing K. Yen ◽  
Jan-Ulrich Thiele ◽  
Hans-Herman Schneider ◽  
James H. Rogers ◽  
...  

Abstract Three different processes, Plasma Enhanced CVD (PECVD), Ion Beam (IB), and Cathodic Arc (CA) have been used to deposit highly energetic carbon films in the 2–10 nm thickness range in commercial, high throughput disk manufacturing tools. The deposition conditions used are typical of those required for disk manufacturing. Raman spectroscopy, I-V measurements, nanoindentation, and AFM based scratch testing have been used to characterize the structural, electrical, and mechanical properties of the films. The measured maximum hardness for the PECVD and IBD films are 28 and 25 GPa, respectively, and found to be influenced by the hardness of the softer substrates for the 70–120nm films available for measurement. The scratch resistance of the CAC films is ∼2× the scratch resistance of the IBD films and 25% greater than the PECVD films. Addition of nitrogen to the films produced by both the PECVD and IB techniques reduces the hardness of the films. Both the Raman and I-V data suggest increasing concentrations of sp2 bonding result from these nitrogen additions.

1994 ◽  
Vol 354 ◽  
Author(s):  
K.C. Walter ◽  
H. Kung ◽  
T. Levine ◽  
J.T. Tesmer ◽  
P. Kodali ◽  
...  

AbstractPlasma and ion beam based techniques have been used to deposit carbon-based films. The ion beam based method, a cathodic arc process, used a magnetically mass analyzed beam and is inherently a line-of-sight process. Two hydrocarbon plasma-based, non-line-of-sight techniques were also used and have the advantage of being capable of coating complicated geometries. The self-bias technique can produce hard carbon films, but is dependent on rf power and the surface area of the target. The pulsed-bias technique can also produce hard carbon films but has the additional advantage of being independent of rf power and target surface area. Tribological results indicated the coefficient of friction is nearly the same for carbon films from each deposition process, but the wear rate of the cathodic arc film was five times less than for the self-bias or pulsed-bias films. Although the cathodic arc film was the hardest, contained the highest fraction of sp3 bonds and exhibited the lowest wear rate, the cathodic arc film also produced the highest wear on the 440C stainless steel counterface during tribological testing. Thus, for tribological applications requiring low wear rates for both counterfaces, coating one surface with a very hard, wear resistant film may detrimentally affect the tribological behavior of the counterface.


2017 ◽  
Vol 743 ◽  
pp. 112-117
Author(s):  
Alexander Zolkin ◽  
Anna Semerikova ◽  
Sergey Chepkasov ◽  
Maksim Khomyakov

In the present study, the Raman spectra of diamond-like amorphous (a-C) and hydrogenated amorphous (a-C:H) carbon films on silicon obtained using the ion-beam methods and the pulse cathodic arc deposition technique were investigated with the aim of elucidating the relation between the hardness and structure of the films. The hardness of the samples used in the present study was 19 – 45 GPa. Hydrogenated carbon films were synthesized using END–Hall ion sources and a linear anode layer ion source (LIS) on single-crystal silicon substrates. The gas precursors were CH4 and C3H8, and the rate of the gas flow fed into the ion source was 4.4 to 10 sccm. The ion energies ranged from 150 to 600 eV. a-C films were deposited onto Si substrates using the pulse cathodic arc deposition technique. The films obtained by the pulse arc technique contained elements with an ordered structure. In the films synthesized using low- (150 eV) and high-energy (600 eV) ions beams, an amorphous phase was the major phase. The significant blurriness of the diffraction rings in the electron diffraction patterns due to a large film thickness (180 – 250 nm) did not allow distinctly observing the signals from the elements with an ordered structure against the background of an amorphous phase.


1995 ◽  
Vol 383 ◽  
Author(s):  
T. Y. Tsui ◽  
G. M. Pharr ◽  
W. C. Oliver ◽  
C. S. Bhatia ◽  
R. L. White ◽  
...  

ABSTRACTNanoindentation and nanoscratching experiments have been performed to assess the mechanical properties of several carbon thin films with potential application as wear resistant coatings for magnetic disks. These include three hydrogenated-carbon films prepared by sputter deposition in a H2/Ar gas mixture (hydrogen contents of 20, 34, and 40 atomic %) and a pure carbon film prepared by cathodic-arc plasma techniques. Each film was deposited on a silicon substrate to thickness of about 300 nm. The hardness and elastic modulus were measured using nanoindentation methods, and ultra-low load scratch tests were used to assess the scratch resistance of the films and measure friction coefficients. The results show that the hardness, elastic modulus, and scratch resistance of the 20% and 34% hydrogenated films are significantly greater than the 40% film, thereby showing that there is a limit to the amount of hydrogen producing beneficial effects. The cathodic-arc film, with a hardness of greater than 59 GPa, is considerably harder than any of the hydrogenated films and has a superior scratch resistance.


1991 ◽  
Vol 223 ◽  
Author(s):  
Qin Fuguang ◽  
Yao Zhenyu ◽  
Ren Zhizhang ◽  
S.-T. Lee ◽  
I. Bello ◽  
...  

ABSTRACTDirect ion beam deposition of carbon films on silicon in the ion energy range of 15–500eV and temperature range of 25–800°C has been studied using mass selected C+ ions under ultrahigh vacuum. The films were characterized with X-ray photoelectron spectroscopy, Raman spectroscopy, and transmission electron microscopy and diffraction analysis. Films deposited at room temperature consist mainly of amorphous carbon. Deposition at a higher temperature, or post-implantation annealing leads to formation of microcrystalline graphite. A deposition temperature above 800°C favors the formation of microcrystalline graphite with a preferred orientation in the (0001) direction. No evidence of diamond formation was observed in these films.


2002 ◽  
Vol 719 ◽  
Author(s):  
Myoung-Woon Moon ◽  
Kyang-Ryel Lee ◽  
Jin-Won Chung ◽  
Kyu Hwan Oh

AbstractThe role of imperfections on the initiation and propagation of interface delaminations in compressed thin films has been analyzed using experiments with diamond-like carbon (DLC) films deposited onto glass substrates. The surface topologies and interface separations have been characterized by using the Atomic Force Microscope (AFM) and the Focused Ion Beam (FIB) imaging system. The lengths and amplitudes of numerous imperfections have been measured by AFM and the interface separations characterized on cross sections made with the FIB. Chemical analysis of several sites, performed using Auger Electron Spectroscopy (AES), has revealed the origin of the imperfections. The incidence of buckles has been correlated with the imperfection length.


2002 ◽  
Vol 20 (6) ◽  
pp. 2072
Author(s):  
Meiyong Liao ◽  
Chunlin Chai ◽  
Shaoyan Yang ◽  
Zhikai Liu ◽  
Fuguang Qin ◽  
...  

1988 ◽  
Vol 140 ◽  
Author(s):  
Irwin L. Singer

AbstractAdvances in solid lubricating films for vacuum and high temperature applications are reviewed. Traditional lubricants (e.g. graphite and dichalcogenides) are being improved and new lubricating materials (e.g. amorphous carbons) are being discovered with the aid of recent developments in deposition processes and surface analytical methods. Ion bombardmenttreatments have increased film adhesion, lowered friction coefficients and enhanced the wearlife of MoS2films, as well as created new forms of lubricating carbons (amorphous, polymeric and diamond-like). Composite films and multilayer coating treatments are providing extra protection for surface and films against environmental degradation. Ultralow friction coefficients (<0.01) have been achieved with MoS 2 as well as diamond-like carbon films. Material selection, in some cases (e.g. thin metal films), can nowbe made basedon scientific principles, although many tribomaterials are still being developed by trialand error methods.


1996 ◽  
Vol 438 ◽  
Author(s):  
R. L. C. Wu ◽  
W. Lanter

AbstractAn ultra high vacuum ion beam system, consisting of a 20 cm diameter Rf excilted (13.56 MHz) ion gun and a four-axis substrate scanner, has been used to modify large surfaces (up to 1000 cm2) of various materials, including; infrared windows, silicon nitride, polycrystalline diamond, 304 and 316 stainless steels, 440C and M50 steels, aluminum alloys, and polycarbonates; by depositing different chemical compositions of diamond-like carbon films. The influences of ion energy, Rf power, gas composition (H2/CH4 , Ar/CH4 and O2/CH4/H2), on the diamond-like carbon characteristics has been studied. Particular attention was focused on adhesion, environmental effects, IR(3–12 μm) transmission, coefficient of friction, and wear factors under spacelike environments of diamond-like carbon films on various substrates. A quadrupole mass spectrometer was utilized to monitor the ion beam composition for quality control and process optimization.


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