Electrical Properties of Hard Carbon Films

1988 ◽  
Vol 131 ◽  
Author(s):  
Walter Varhue ◽  
Kiril Pandelisev ◽  
Brian Shinseki
Keyword(s):  
Electrical Properties ◽  
Optical Band Gap ◽  
Carbon Films ◽  
Operating Conditions ◽  
Hard Carbon ◽  
Ion Energy ◽  
Preparation Conditions ◽  
Amorphous Medium ◽  
Bonding Ratio ◽  
Species Production

ABSTRACTThe electrical resistivity, optical band gap and activation energy for electrical conduction have been determined as a function of preparation conditions. The operating conditions for the glow discharge reactor have been interpreted in terms of ion energy and reactive species production. The change in the electrical properties could not be explained as a percentage of [SP3] versus [SP2] bonding ratio. Rather, these two species are embedded in an amorphous medium which determines the materials electrical properties.

Hard Carbon Films with Various Microstructure Prepared by Ion Assisted Evaporation

1993 ◽  
Vol 316 ◽  
Author(s):  
J. Ullmann ◽  
A. Weber ◽  
U. Falke
Keyword(s):  
Growth Mechanism ◽  
Film Growth ◽  
Carbon Films ◽  
Carbon Surface ◽  
Vickers Indentation ◽  
Structure Modification ◽  
Hard Carbon ◽  
Ion Etching ◽  
Ion Energy ◽  
Free Ion

ABSTRACTFor a deeper understanding of the creation of carbon films the hydrogen-free ion assisted evaporation (IAE) method with neon species was used. Variation of the ion parameters energy and ion to neutral arrival ratio, delivering the necessary energy for modification of the film growth, results in different microstructures investigated with EELS, HRTEM and TED as well as different microhardnesses measured by dynamical Vickers indentation. A possible film growth mechanism is proposed based on an ion etching of mainly sp2-bonded carbon surface atoms and on defect dominated structure modification below the surface depending on the ion energy

Optical Band Gap of Diamond-Like Carbon Films as a Function of RF Substrate Bias

1989 ◽  
Vol 162 ◽  
Author(s):  
P. W. Pastel ◽  
W. J. Varhue
Keyword(s):  
Band Gap ◽  
Cyclotron Resonance ◽  
Optical Band Gap ◽  
Electron Cyclotron Resonance ◽  
Chemical Vapor ◽  
Carbon Films ◽  
Diamond Like Carbon ◽  
Substrate Bias ◽  
Ion Energy ◽  
Resonance Plasma

ABSTRACTDiamond-like carbon films have been deposited with a low temperature 2.45 GHz electron cyclotron resonance plasma enhanced chemical vapor deposition system. The bombarding ion energy was independently controlled with a RF bias to the substrate. The production rate of reactant species and the impinging ion energy are decoupled with this system. The optical band gap decreased from 2.7 to 1.2 eV as substrate bias was increased from 0 to -140 V.

Electrical properties of hard carbon films

1992 ◽  
Vol 73 (5) ◽  
pp. 941-943
Author(s):  
D. SLAVÍNSKÁ ◽  
L. POSPÍŠILOVÁ ◽  
H. BIEDERMAN ◽  
M. HLAVÁČ
Keyword(s):  
Electrical Properties ◽  
Carbon Films ◽  
Hard Carbon

Structural and Electrical Properties of Phosphorous-Doped Amorphous Diamond

1997 ◽  
Vol 498 ◽  
Author(s):  
S. M. Camphausen ◽  
A. F. Myers ◽  
S. P. Bozeman ◽  
J. J. Cuomo
Keyword(s):  
Electrical Properties ◽  
Room Temperature ◽  
Carbon Films ◽  
Hard Carbon ◽  
Graphite Target ◽  
Amorphous Films ◽  
Carbon Species ◽  
Structural And Electrical Properties ◽  
Phosphorus Doped ◽  
Cathodic Arc

ABSTRACTHard carbon films can be prepared by the condensation of energetic carbon species at or below room temperature. These amorphous films are primarily tetrahedrally coordinated and contain high fractions of sp3 bonds leading to the terminology amorphous diamond. These films have been successfully doped with phosphorus up to 1 at.%, by other researchers by using a phosphorus doped graphite target. We have also investigated evaporated phosphorus in conjuction with a filtered cathodic arc to incorporate phosphorus into the films and have successfully incorporated phosphorus up to 40 at.% into our films using this technique. XPS showed that some of the phosphorus was clustered. PEELS revealed that with an incorporation of 40 at.% of phosphorus, the sp3 content was approximately 20%.

Interpretation of irradiation-induced changes in electron diffractograms and images of extinction contours at low temperatures

1984 ◽  
Vol 42 ◽  
pp. 268-269
Author(s):  
E. Knapek ◽  
H. Formanek ◽  
G. Lefranc ◽  
I. Dietrich
Keyword(s):  
Low Temperatures ◽  
Carbon Films ◽  
Organic Crystals ◽  
Wide Spread ◽  
Lens System ◽  
Preparation Conditions ◽  
Thin Carbon ◽  
Electron Diffractograms ◽  
Diffraction Patterns ◽  
Induced Changes

A few years ago results on cryoprotection of L-valine were reported, where the values of the critical fluence De i.e, the electron exposure which decreases the intensity of the diffraction reflections by a factor e, amounted to the order of 2000 + 1000 e/nm2. In the meantime a discrepancy arose, since several groups published De values between 100 e/nm2 and 1200 e/nm2 /1 - 4/. This disagreement and particularly the wide spread of the results induced us to investigate more thoroughly the behaviour of organic crystals at very low temperatures during electron irradiation.For this purpose large L-valine crystals with homogenuous thickness were deposited on holey carbon films, thin carbon films or Au-coated holey carbon films. These specimens were cooled down to nearly liquid helium temperature in an electron microscope with a superconducting lens system and irradiated with 200 keU-electrons. The progress of radiation damage under different preparation conditions has been observed with series of electron diffraction patterns and direct images of extinction contours.

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.

scholarly journals Characterization and Performance of Carbon Films Deposited by Plasma and Ion Beam Based Techniques

1994 ◽  
Vol 354 ◽  
Author(s):  
K.C. Walter ◽  
H. Kung ◽  
T. Levine ◽  
J.T. Tesmer ◽  
P. Kodali ◽  
...  
Keyword(s):  
Wear Rate ◽  
Surface Area ◽  
Ion Beam ◽  
Carbon Films ◽  
The Self ◽  
Line Of Sight ◽  
Rf Power ◽  
Hard Carbon ◽  
Self Bias ◽  
Cathodic Arc

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.

Large Area Surface Treatment by Ion Beam Technology

1996 ◽  
Vol 438 ◽  
Author(s):  
R. L. C. Wu ◽  
W. Lanter
Keyword(s):  
Ion Beam ◽  
High Vacuum ◽  
Polycrystalline Diamond ◽  
Carbon Films ◽  
Ultra High Vacuum ◽  
Diamond Like Carbon ◽  
Chemical Compositions ◽  
Rf Power ◽  
Large Area ◽  
Ion Energy

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.

EFFECT OF DISORDER ON THE ELECTRICAL PROPERTIES OF AMORPHOUS CONDUCTING CARBON FILMS: OBSERVANCE OF FIELD INDUCED METAL-INSULATOR TRANSITION?

2000 ◽  
Vol 14 (02n03) ◽  
pp. 224-229 ◽  
Author(s):  
V. MEENAKSHI ◽  
S. V. SUBRAMANYAM
Keyword(s):  
Magnetic Field ◽  
Electrical Properties ◽  
External Magnetic Field ◽  
Low Temperature ◽  
Carbon Films ◽  
Electronic Systems ◽  
Metal Insulator Transition ◽  
Preparation Temperature ◽  
Metal Insulator ◽  
Effect Of Disorder

In this work, the influence of disorder on the electrical properties (DC conductivity and Magnetoresistance) of amorphous conducting carbon films, prepared by the pyrolysis of Tetra chloro phthalic anhydride, is reported and discussed. The low temperature electrical properties are analyzed in terms of the various models developed for disordered electronic systems. The results indicate the possibility of a metal - insulator (M-I) transition, both as a function of preparation temperature and an external magnetic field.

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