Elastic Properties of Diamond-Like Amorphous Carbon Films Grown by Computer Simulation of Ion-Beam Deposition Process

2000 ◽  
Vol 648 ◽  
Author(s):  
A.Yu. Belov ◽  
H.U. Jäger
Keyword(s):  
Amorphous Carbon ◽  
Elastic Constants ◽  
Ion Beam ◽  
Carbon Films ◽  
Atomic Scale ◽  
Ion Energy ◽  
Amorphous Carbon Films ◽  
Ion Beam Deposition ◽  
Bulk Stress ◽  
Beam Deposition

AbstractAtomic-scale calculations were performed for the first time to investigate mechanical properties of amorphous carbon films grown by a realistic simulation of ion-beam deposition. The simulated films have a thickness of a few nanometers and reproduce the main structural features of real films, with the bulk content of sp3 bonded atoms varying from 35 to 95%, depending on the ion energy (E = 20-80 eV). Employing empirical interatomic potentials for carbon, the average bulk stresses as well as the atomic-level stress distributions were calculated and analysed. The bulk stresses were found to depend not only on the ion energy, but also on the film quality, in particular, on such structural inhomogeneities as local fluctuations of the sp3 fraction with the depth. The local variation of the bulk stress from the average value considerably increases as the local content of sp2 bonded atoms increases. Elastic constants of amorphous carbon films were also computed using the method of inner elastic constants, which allows for the stress dependence of elastic constants to be analysed. The variation of Young's modulus as a function of the lateral bulk stress in an amorphous film is demonstrated.

Ion Beam Deposition of Amorphous Carbon Films With Diamond Like Properties

1981 ◽  
Vol 7 ◽  
Author(s):  
John C. Angus ◽  
Michael J. Mirtich ◽  
Edwin G. Wintucky
Keyword(s):  
Amorphous Carbon ◽  
Growth Rates ◽  
Random Network ◽  
Ion Beam ◽  
Potassium Bromide ◽  
Carbon Films ◽  
Amorphous Carbon Films ◽  
Ion Beam Deposition ◽  
Beam Deposition

ABSTRACTCarbon films were deposited on silicon, quartz, and potassium bromide substrates from an ion beam. Growth rates were approximately 0.3 μm/hour. The films were featureless and amorphous and contained only carbon and hydrogen in significant amounts. The density and carbon/hydrogen ratio indicate the film is a hydrogen deficient polymer. One possible structure, consistent with the data, is a random network of methylene linkages and tetrahedrally coordinated carbon atoms.

Direct ion beam deposition of carbon films on silicon in the ion energy range of 15–500 eV

1991 ◽  
Vol 70 (10) ◽  
pp. 5623-5628 ◽  
Author(s):  
W. M. Lau ◽  
I. Bello ◽  
X. Feng ◽  
L. J. Huang ◽  
Qin Fuguang ◽  
...  
Keyword(s):  
Energy Range ◽  
Ion Beam ◽  
Carbon Films ◽  
Ion Energy ◽  
Ion Beam Deposition ◽  
Beam Deposition

Characterization of Films Made from Silicon Oil Saturated Methane Vapor by Ion Beam

1992 ◽  
Vol 279 ◽  
Author(s):  
Sin-Shong Lin ◽  
Janes M. Sloan
Keyword(s):  
Saturated Vapor ◽  
Ion Beam ◽  
Carbon Films ◽  
Amorphous Carbon Films ◽  
X Ray ◽  
Silicon Oil ◽  
Ion Beam Deposition ◽  
Steel Substrates ◽  
Beam Deposition

ABSTRACTAmorphous carbon films were prepared by the ion beam deposition of methane saturated with silicon pump oil 704. The concentration of Si in the ion deposited coatings could be varied by the temperature of silicon oil bath where saturated vapor was produced. In the process, the vapor ionized at 800 V was accelerated and impinged on glass or stainless steel substrates at ion densities between 0.3–1.5 mA/cm2 for a period of less than 60 minutes. The resulting films were characterized by x-ray photoelectron and Raman spectroscopies. The elemental components of these films include carbon, oxygen and silicon with varying amounts of nitrogen, iron and tungsten contaminations. The microstructure mainly consists of tiny graphitic carbon with sp2 ordered and disordered configurations, numerous carbon-oxygen and carbon-silicon linkages. This simple unique process yields a homogeneous thin coating suitable for many tribological applications.

Scanning Tunneling Microscopy of Amorphous Carbon Films

1990 ◽  
Vol 48 (1) ◽  
pp. 318-319
Author(s):  
Mircea Fotino ◽  
D.C. Parks
Keyword(s):  
Scanning Tunneling Microscopy ◽  
Amorphous Carbon ◽  
Carbon Films ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Amorphous Carbon Films ◽  
Image Optimization ◽  
Step Procedure ◽  
Stm Images

In the last few years scanning tunneling microscopy (STM) has made it possible and easily accessible to visualize surfaces of conducting specimens at the atomic scale. Such performance allows the detailed characterization of surface morphology in an increasing spectrum of applications in a wide variety of fields. Because the basic imaging process in STM differs fundamentally from its equivalent in other well-established microscopies, good understanding of the imaging mechanism in STM enables one to grasp the correct information content in STM images. It thus appears appropriate to explore by STM the structure of amorphous carbon films because they are used in many applications, in particular in the investigation of delicate biological specimens that may be altered through the preparation procedures.All STM images in the present study were obtained with the commercial instrument Nanoscope II (Digital Instruments, Inc., Santa Barbara, California). Since the importance of the scanning tip for image optimization and artifact reduction cannot be sufficiently emphasized, as stressed by early analyses of STM image formation, great attention has been directed toward adopting the most satisfactory tip geometry. The tips used here consisted either of mechanically sheared Pt/Ir wire (90:10, 0.010" diameter) or of etched W wire (0.030" diameter). The latter were eventually preferred after a two-step procedure for etching in NaOH was found to produce routinely tips with one or more short whiskers that are essentially rigid, uniform and sharp (Fig. 1) . Under these circumstances, atomic-resolution images of cleaved highly-ordered pyro-lytic graphite (HOPG) were reproducibly and readily attained as a standard criterion for easily recognizable and satisfactory performance (Fig. 2).

Carbon Film Deposition On Silicon Using Low Energy Ion Beams

1991 ◽  
Vol 223 ◽  
Author(s):  
Qin Fuguang ◽  
Yao Zhenyu ◽  
Ren Zhizhang ◽  
S.-T. Lee ◽  
I. Bello ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Ion Beam ◽  
Carbon Film ◽  
Carbon Films ◽  
Film Deposition ◽  
Ion Energy ◽  
Transmission Electron ◽  
Higher Temperature ◽  
Post Implantation ◽  
Beam Deposition

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.

The influence of substrate temperature during ion beam deposition on the diamond-like or graphitic nature of carbon films

1993 ◽  
Vol 2 (2-4) ◽  
pp. 285-290 ◽  
Author(s):  
Y. Lifshitz ◽  
G.D. Lempert ◽  
S. Rotter ◽  
I. Avigal ◽  
C. Uzan-Saguy ◽  
...  
Keyword(s):  
Substrate Temperature ◽  
Ion Beam ◽  
Carbon Films ◽  
Ion Beam Deposition ◽  
Influence Of Substrate ◽  
Beam Deposition

Growth of diamond and diamond-like films using a low energy ion beam

1998 ◽  
Vol 13 (8) ◽  
pp. 2315-2320 ◽  
Author(s):  
Y. P. Guo ◽  
K. L. Lam ◽  
K. M. Lui ◽  
R. W. M. Kwok ◽  
K. C. Hui
Keyword(s):  
Ion Beam ◽  
Chemical Vapor ◽  
Carbon Films ◽  
Low Energy ◽  
Hydrogen Passivation ◽  
Heteroepitaxial Growth ◽  
Ion Beam Deposition ◽  
Additional Control ◽  
Strain Release ◽  
Beam Deposition

Ion beam deposition provides an additional control of ion beam energy over the chemical vapor deposition methods. We have used a low energy ion beam of hydrogen and carbon to deposit carbon films on Si(100) wafers. We found that graphitic films, amorphous carbon films, and oriented diamond microcrystallites could be obtained separatedly at different ion beam energies. The mechanism of the formation of the oriented diamond microcrystallites was suggested to include three components: strain release after ion bombardment, hydrogen passivation of sp3 carbon, and hydrogen etching. Such a process can be extended to the heteroepitaxial growth of diamond films.

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