Carbon Surfaces and Carbon Film Morphology Studied by Emission Electron Microscopy

1990 ◽  
Vol 48 (1) ◽  
pp. 562-563
Author(s):  
Congjun Wang ◽  
Martin E. Kordesch
Keyword(s):  
Surface Science ◽  
Thermal Emission ◽  
Incident Light ◽  
Carbon Film ◽  
Nucleation And Growth ◽  
Carbon Films ◽  
Carbon Coated ◽  
Emission Microscopy ◽  
Incident Light Wavelength ◽  
The One

Carbon is a pervasive contaminant on technologically important surfaces, and has long been of interest in surface science and microscopy. Recent advances in the production of high density carbon films and synthetic diamond films [1,2] have focused attention on the nucleation and growth of carbon on refractory metal substrates, semiconductors and other phases of carbon itself. Some of the issues involved are the role of carbides in promoting diamond nucleation and the specifics of graphite removal from the film through reactive sputtering or conversion to more dense phases (by as yet not understood processes).Emission microscopy, in particular photo- and thermal emission microscopy, is especially suited to the study of carbon film nucleation and growth. Carbides are easily observed. [3] Because several carbon phases have differing work functions, they may be selectively imaged by variation of the incident light wavelength, and thus the photoemission threshold, providing information on film composition in the image. Figures 1 and 2 show a Pt(100) surface covered with CO, atomic carbon and some graphitic areas, imaged with a microscope similar to the one in [3] using an HBO 100 lamp. [4] In figure 2 a 280 nm edge filter was placed in front of the lamp, so that only the graphitic areas (work function below 4.4 eV) are visible. Due to the image contrast in photoemission from differing materials, decoration of steps and defects by carbon is visible. In figure 3 step bunch edges on the Pt(100) surface have been decorated with carbon from the decomposition of ethylene; figure 4 shows another area of the surface where the terraces are carbon coated, and the step edges are “clean.” The slip trace features suggest that the dark lines are mono-atomic steps.[5]

Benzylamine Tartrate as an Organic Glass Substrate for Carbon Films by Evaporation

1970 ◽  
Vol 28 ◽  
pp. 484-485
Author(s):  
A. C. Faberge
Keyword(s):  
Vapor Pressure ◽  
Viscous Liquid ◽  
Glass Substrate ◽  
Room Temperature ◽  
Carbon Film ◽  
Carbon Films ◽  
Organic Glass ◽  
Spectroscopic Examination ◽  
Polymeric Substrates

Benzylamine tartrate (m.p. 63°C) seems to be a better and more convenient substrate for making carbon films than any of those previously proposed. Using it in the manner described, it is easy consistently to make batches of specimen grids as open as 200 mesh with no broken squares, and without individual handling of the grids. Benzylamine tartrate (hereafter called B.T.) is a viscous liquid when molten, which sets to a glass. Unlike polymeric substrates it does not swell before dissolving; such swelling of the substrate seems to be a principal cause of breakage of carbon film. Mass spectroscopic examination indicates a vapor pressure less than 10−9 Torr at room temperature.

Fundamental Research into Thin Films in a Developing Country

1972 ◽  
Vol 30 ◽  
pp. 500-501
Author(s):  
J.A. Eades ◽  
E. Grünbaum
Keyword(s):  
Thin Films ◽  
Growth Process ◽  
Empirical Process ◽  
Nucleation And Growth ◽  
Research Groups ◽  
Film Research ◽  
Fundamental Research ◽  
Controlled Deposition ◽  
The One ◽  
The University

In the last decade and a half, thin film research, particularly research into problems associated with epitaxy, has developed from a simple empirical process of determining the conditions for epitaxy into a complex analytical and experimental study of the nucleation and growth process on the one hand and a technology of very great importance on the other. During this period the thin films group of the University of Chile has studied the epitaxy of metals on metal and insulating substrates. The development of the group, one of the first research groups in physics to be established in the country, has parallelled the increasing complexity of the field.The elaborate techniques and equipment now needed for research into thin films may be illustrated by considering the plant and facilities of this group as characteristic of a good system for the controlled deposition and study of thin films.

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.

Application of Backside Photo and Thermal Emission Microscopy Techniques to Advanced Memory Devices

1997 ◽  
Author(s):  
S.-S. Lee ◽  
J.-S. Seo ◽  
N.-S. Cho ◽  
S. Daniel
Keyword(s):  
Thermal Emission ◽  
Test Cases ◽  
Memory Devices ◽  
Front Side ◽  
Emission Analysis ◽  
Intensity Attenuation ◽  
Analysis Techniques ◽  
Defect Sites ◽  
Emission Microscopy ◽  
Microscopy Techniques

Abstract Both photo- and thermal emission analysis techniques are used from the backside of the die colocate defect sites. The technique is important in that process and package technologies have made front-side analysis difficult or impossible. Several test cases are documented. Intensity attenuation through the bulk of the silicon does not compromise the usefulness of the technique in most cases.

Stress Whitening in Polypropylene. I. Light Scattering Theory and Model Experiments

1995 ◽  
Vol 60 (11) ◽  
pp. 1875-1887 ◽  
Author(s):  
Jaroslav Holoubek ◽  
Miroslav Raab
Keyword(s):  
Refractive Index ◽  
Light Scattering ◽  
Incident Light ◽  
Polymeric Materials ◽  
Wavelength Dependence ◽  
Theoretical Background ◽  
Surrounding Matrix ◽  
Embedded Particles ◽  
The One ◽  
Stress Whitening

Theoretical background for an optical method is presented which makes it possible to distinguish unambiguously between voids and particles as light scattering sites in polymeric materials. Typical dependences of turbidity as a function of diameter of scattering elements, their volume fractions and also turbidity curves as a function of the wavelength of the incident light were calculated, based both on the Lorenz-Mie theory and the fluctuation theory. Such dependences calculated for polypropylene-containing voids on the one hand and particles, differing only slightly from the surrounding matrix in their refractive index, on the other hand, are markedly different. The most significant results are: (i) Turbidity is at least by two orders of magnitude larger for voids in comparison to embedded particles of ethylene-propylene (EPDM) rubber of the same size, concentration and at the same wavelength. (ii) The wavelength dependence of turbidity for EPDM particles and the inherent refractive index fluctuations in the polypropylene matrix is much steeper as compared to voids for all considered diameters (0.1-10 μm). Thus, the nature of stress whitening in complex polymeric materials can be determined from turbidity measurements.

scholarly journals Field Emission from Carbon Films Deposited by Controlled-Low-Energy Beams and CVD Sources

1999 ◽  
Vol 585 ◽  
Author(s):  
Douglas H. Lowndes ◽  
Vladimir I. Merkulov ◽  
L. R. Baylor ◽  
G. E. Jellison ◽  
D. B. Poker ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Surface Morphology ◽  
Field Emission ◽  
Metal Ion ◽  
Ion Beam ◽  
Pyrolytic Graphite ◽  
Carbon Film ◽  
Chemical Vapor ◽  
Carbon Films ◽  
Damage Site

AbstractThe principal interests in this work are energetic-beam control of carbon-film properties and the roles of doping and surface morphology in field emission. Carbon films with variable sp3-bonding fraction were deposited on n-type Si substrates by ArF (193 nm) pulsed-laser ablation (PLA) of a pyrolytic graphite target, and by direct metal ion beam deposition (DMIBD) using a primary Cs+ beam to generate the secondary C- deposition beam. The PLA films are undoped while the DMIBD films are doped with Cs. The kinetic energy (KE) of the incident C atoms/ions was controlled and varied over the range from ∼25 eV to ∼175 eV. Earlier studies have shown that C films' sp3-bonding fraction and diamond-like properties can be maximized by using KE values near 90 eV. The films' surface morphology, sp3–bonding fraction, and Cs-content were determined as a function of KE using atomic force microscopy, TEM/EELS, Rutherford backscattering and nuclear reaction measurements, respectively. Field emission (FE) from these very smooth undoped and Cs-containing films is compared with the FE from two types of deliberately nanostructured carbon films, namely hot-filament chemical vapor deposition (HF-CVD) carbon and carbon nanotubes grown by plasma-enhanced CVD. Electron field emission (FE) characteristics were measured using ∼25-μm, ∼5-μm and ∼1-μm diameter probes that were scanned with ∼75 nm resolution in the x-, y-, and z-directions in a vacuum chamber (∼5 × 10-7 torr base pressure) equipped with a video camera for viewing. The hydrogen-free and very smooth a-D or a-C films (with high or low sp3 content, and with or without ∼1% Cs doping) produced by PLD and DMIBD are not good field emitters. Conditioning accompanied by arcing was required to obtain emission, so that their subsequent FE is characteristic of the arc-produced damage site. However, deliberate surface texturing can eliminate the need for conditioning, apparently by geometrical enhancement of the local electric field. But the most promising approach for producing macroscopically flat FE cathodes is to use materials that are highly nanostructured, either by the deposition process (e.g. HF-CVD carbon) or intrinsically (e.g. carbon nanotubes). HF-CVD films were found to combine a number of desirable properties for FE displays and vacuum microelectronics, including the absence of conditioning, low turn-on fields, high emission site density, and apparent stability and durability during limited long-term testing. Preliminary FE measurements revealed that vertically aligned carbon nanotubes are equally promising.

scholarly journals Robust low friction performance of graphene sheets embedded carbon films coated orthodontic stainless steel archwires

Friction ◽  
2021 ◽  
Author(s):  
Zonglin Pan ◽  
Qinzhao Zhou ◽  
Pengfei Wang ◽  
Dongfeng Diao
Keyword(s):  
Stainless Steel ◽  
Friction Coefficient ◽  
Orthodontic Treatment ◽  
Artificial Saliva ◽  
Carbon Film ◽  
Carbon Films ◽  
Graphene Sheets ◽  
Substrate Bias ◽  
Low Friction ◽  
Substrate Bias Voltage

AbstractReducing the friction force between the commercial archwire and bracket during the orthodontic treatment in general dental practice has attracted worldwide interest. An investigation on the friction and wear behaviors of the uncoated and carbon film coated stainless steel archwires running against stainless steel brackets was systematically conducted. The carbon films were prepared at substrate bias voltages from +5 to +50 V using an electron cyclotron resonance plasma sputtering system. With increasing substrate bias voltage, local microstructures of the carbon films evolved from amorphous carbon to graphene nanocrystallites. Both static and stable friction coefficients of the archwire-bracket contacts sliding in dry and wet (artificial saliva) conditions decreased with the deposition of carbon films on the archwires. Low friction coefficient of 0.12 was achieved in artificial saliva environment for the graphene sheets embedded carbon (GSEC) film coated archwire. Deterioration of the friction behavior of the GSEC film coated archwire occurred after immersion of the archwire in artificial saliva solution for different periods before friction test. However, moderate friction coefficient of less than 0.30 sustained after 30 days immersion periods. The low friction mechanism is clarified to be the formation of salivary adsorbed layer and graphene sheets containing tribofilm on the contact interfaces. The robust low friction and low wear performances of the GSEC film coated archwires make them good candidates for clinical orthodontic treatment applications.

scholarly journals Properties and Analysis of Transparency Conducting AZO Films by Using DC Power and RF Power Simultaneous Magnetron Sputtering

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Neng-Fu Shih ◽  
Jin-Zhou Chen ◽  
Yeu-Long Jiang
Keyword(s):  
Incident Light ◽  
Blue Shift ◽  
Light Wavelength ◽  
Rf Power ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dc Power ◽  
Incident Light Wavelength ◽  
Significant Blue Shift ◽  
Sputtering System

DC power and RF power were introduced into the magnetic controlled sputtering system simultaneously to deposit AZO films in order to get an acceptable deposition rate with high quality transparency conducting thin film. The resistivity decreases with the RF power for the as-deposited samples. The resistivity of 6 × 10−4 Ω-cm and 3.5–4.5 × 10−4 Ω-cm is obtained for the as-deposited sample, and for all annealed samples, respectively. The transmittance of the AZO films with higher substrate temperature is generally above 80% for the incident light wavelength within 400–800 nm. The transmittance of the as-deposited samples reveals a clear blue shift phenomenon. The AZO films present (002) oriented preference as can be seen from the X-ray diffraction curves. All AZO films reveal compressive stress. The annealing process improves the electrical property of AZO films. A significant blue shift phenomenon has been found, which may have a great application for electrode in solar cell.

scholarly journals Numerical simulation of a plasmonic lens for laser light focusing

2021 ◽  
Vol 2103 (1) ◽  
pp. 012174
Author(s):  
E S Kozlova ◽  
V V Kotlyar
Keyword(s):  
Focal Spot ◽  
Laser Light ◽  
Incident Light ◽  
Lens Design ◽  
Light Wavelength ◽  
Optimal Parameters ◽  
Plasmonic Lens ◽  
Radial Polarization ◽  
Incident Light Wavelength ◽  
Difference Time

Abstract In this paper, the design of a plasmonic lens in gold and silver thin films for focusing the light with radial polarization is presented. Using the finite difference time domain method the optimal parameters of the plasmonic lens design are found. It was shown that the silver plasmonic lens produces a tight focal spot with a full width at half maximum of 0.38 of the incident light wavelength.

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