Preparation and Characterization of Chromium Containing amorphous Hydrogenated Carbon Films (A-C:H/Cr)

1995 ◽  
Vol 388 ◽  
Author(s):  
R. Gampp ◽  
P. Gantenbein ◽  
P. Oelhafen
Keyword(s):  
Chromium Carbide ◽  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Carbon Films ◽  
Rf Plasma ◽  
Silicon Substrates ◽  
Amorphous Hydrogenated Carbon ◽  
High Chemical Stability

AbstractChromium containing amorphous hydrogenated carbon films (a-C:H/Cr) were prepared in a process that combines rf plasma activated chemical vapor deposition of methane and magnetron sputtering of a chromium target. During the deposition the silicon substrates were kept at 200°C and dc biased at -200 V in order to obtain films with high chemical stability which is required for the application as solar selective surfaces. the films with different Cr concentrations (5 to 49 at.%) were characterized by in situ x-ray photoelectron spectroscopy (XPS). Up to 40 at.%, chromium proves to be built into the cermet-like films in the form of chromium carbide clusters. above 40 at.%, chromium is partly metallic. a modification of the a-C:H matrix in the vicinity of the chromium carbide clusters has been observed.

In Situ Plasma Analysis, Fluorine Incorporation, Thermostability, Stress, and Hardness Comparison of Fluorinated Amorphous Carbon and Hydrogenated Amorphous Carbon Thin Films Deposited on Si by Plasma Enhanced Chemical Vapor Deposition

1999 ◽  
Vol 565 ◽  
Author(s):  
A. D. Glew ◽  
M. A. Cappelli ◽  
M. N. Touzelbaev ◽  
Y. Hu
Keyword(s):  
Amorphous Carbon ◽  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Film Stress ◽  
In Situ Observation ◽  
Plasma Properties ◽  
Thin Film Stress ◽  
The Relationship ◽  
Amorphous Hydrogenated Carbon

AbstractIn situ observation of the plasma properties during deposition of fluorinated amorphous hydrogenated carbon (FLAC) and unfluorinated amorphous hydrogenated carbon are performed. The relationship between film properties and impinging ion energy and incident ion momentum is discussed within the framework of existing models of diamond-like carbon (DLC) formation. The DLC films are deposited in a low pressure radio frequency discharge operating at 13.57 MHz with methane and carbon tetra-fluoride as the source gases. Thermostability, stress, and mechanical properties are investigated. The films are elevated to 400 degrees C in order to investigate thermostability. Thin film stress and nano-hardness are also studied. The film density is investigated by gravimetric methods. The fluorinated film stoichiometry is explored with x-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy.

scholarly journals Changing Contents of Carbon Hybridizations in Amorphous Hydrogenated Carbon Layers (a-C:H) on Sustainable Polyhydroxybutyrate (PHB) Exhibit a Significant Deterioration in Stability, Depending on Thickness

2019 ◽  
Vol 5 (3) ◽  
pp. 52 ◽  
Author(s):  
Torben Schlebrowski ◽  
Lucas Beucher ◽  
Hadi Bazzi ◽  
Barbara Hahn ◽  
Stefan Wehner ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Raw Materials ◽  
Chemical Vapor ◽  
Drift Spectroscopy ◽  
Significant Deterioration ◽  
X Ray ◽  
Diffuse Reflectance Infrared ◽  
X Ray Absorption ◽  
Amorphous Hydrogenated Carbon

PHB is a biodegradable polymer based on renewable raw materials that could replace synthetic polymers in many applications. A big advantage is the resulting reduction of the waste problem, as well as the conservation of fossil resources. To arrange it for various applications, the surface is arranged by plasma-enhanced chemical vapor deposition (PECVD) with amorphous hydrogenated carbon layers (a-C:H). Here, on a 50 µm thick PHB-foil, a-C:H layers of different thicknesses (0–500 nm) were deposited in 50 nm steps. Surface topography was investigated by scanning electron microscopy (SEM), chemical composition by diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy and wettability checked by contact angle. In addition, layers were examined by synchrotron supported X-ray photoelectron spectroscopy (XPS) and near edge X-ray absorption fine structure (NEXAFS), which revealed thickness dependent changes of the sp2/sp3 ratio. With increasing thickness, even the topography changes show internal, stress-induced phenomena. The results obtained provide a more detailed understanding of the predominantly inorganic a-C:H coatings on (bio)polymers via in situ growth.

In-Situ Preparation and Characterization of Superconducting Thin Films and Related Materials by Mocvd for the Development of Three Terminal Switching Devices

1989 ◽  
Vol 169 ◽  
Author(s):  
R. Singh ◽  
S. Sinha ◽  
J. Narayan
Keyword(s):  
Thin Films ◽  
High Temperature Superconductor ◽  
Chemical Vapor ◽  
Silicon Substrates ◽  
Superconducting Thin Films ◽  
In Situ Preparation ◽  
In Situ Deposition ◽  
Rapid Isothermal Processing

AbstractMetalorganic chemical vapor deposition (MOCVD) has the potential of emerging as a major technique for the fabrication of high temperature superconductor devices. In this paper, we present preliminary results of in-situ deposition of Y-Ba-Cu-0 thin films (Tc = 79K) by rapid isothermal processing assisted MOCVD on BaF2/silicon substrates.

Characterization Of Amorphous Carbon Films Based On Carbon, Nitrogen, and hydrogen*.

1995 ◽  
Vol 415 ◽  
Author(s):  
H. Efstathiadis ◽  
Z. Akkerman ◽  
F. W. Smith
Keyword(s):  
Optical Constants ◽  
Chemical Vapor ◽  
Carbon Films ◽  
Amorphous Carbon Films ◽  
A Value ◽  
Energy Gaps ◽  
Free Energy Model ◽  
Nitrogen Alloy ◽  
Amorphous Hydrogenated Carbon

ABSTRACTA series of amorphous hydrogenated carbon-nitrogen alloy films (a-CxNyHz) has been prepared via plasma-enhanced chemical vapor deposition from mixtures of nitrogen and acetylene. It is found that as the ratio R=N2/C2H2 is increased from zero to 100, the nitrogen incorporation into the films is increasing while the deposition rate is decreasing for 0<R<10 and is saturating at a value of about 1.0 A/sec for 10<R<100. The absorption associated with the N-H stretching mode increases while that of the C-H stretching mode decreases with increase of R. The optical constants and the energy gaps of these films have also been determined. A free energy model previously developed for the prediction of the bonding in amorphous a-CxHyalloys is extended and applied here to a-CxNyHz. Predictions are presented for the bonding of tetrahedral C(sp3), trigonal C(sp2), linear C(sp1), pyramidal N(sp 3), trigonal N(sp 2), and linear N(sp1) atoms in the alloy, and the bonding of H to these atoms.

scholarly journals Refinement of Sustainable Polybutylene Adipate Terephthalate (PBAT) with Amorphous Hydrogenated Carbon Films (a-C:H) Revealing Film Instabilities Influenced by a Thickness-Dependent Change of sp2/sp3 Ratio

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1077 ◽  
Author(s):  
Torben Schlebrowski ◽  
Halima Acharchi ◽  
Barbara Hahn ◽  
Stefan Wehner ◽  
Christian B. Fischer
Keyword(s):  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
Carbon Films ◽  
Organic Polymer ◽  
X Ray ◽  
Angle Measurements ◽  
Dependent Change ◽  
Contact Angle Measurements ◽  
Diffuse Reflectance Infrared ◽  
Amorphous Hydrogenated Carbon

The increasing use of polymers is related to a growing disposal problem. Switching to biodegradable polymers such as polybutylene adipate terephthalate (PBAT) is a feasible possibility, but after industrial production of commercially available material PBAT is not suitable for every application. Therefore, surface refinements with amorphous hydrogenated carbon films (a-C:H) produced by plasma-assisted chemical vapor deposition (PE-CVD) changing the top layer characteristics are used. Here, 50 µm-thick PBAT films are coated with a-C:H layers up to 500 nm in 50 nm steps. The top surface sp2/sp3 bonding ratios are analyzed by X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) both synchrotron-based. In addition, measurements using diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) were performed for detailed chemical composition. Surface topography was analyzed by scanning electron microscopy (SEM) and the surface wettability by contact angle measurements. With increasing a-C:H layer thickness not only does the topography change but also the sp2 to sp3 ratio, which in combination indicates internal stress-induced phenomena. The results obtained provide a more detailed understanding of the mostly inorganic a-C:H coatings on the biodegradable organic polymer PBAT via in situ growth and stepwise height-dependent analysis.

Chemical Vapor Deposition of Ultrafine Ceramic Structures

1988 ◽  
Vol 132 ◽  
Author(s):  
B. M. Gallois ◽  
R. Mathur ◽  
S. R. Lee ◽  
J. Y. Yoo
Keyword(s):  
Composite Coatings ◽  
Chemical Vapor ◽  
Columnar Structure ◽  
Carbon Films ◽  
Rf Plasma ◽  
Subgrain Structure ◽  
Ultrafine Grained ◽  
Vapor Liquid Solid Mechanism ◽  
Hydrogen Mixtures

ABSTRACTUltrafine ceramic structures based on the nitrides and carbides of titanium and silicon have been synthesized in a computer-controlled hot-wall CVD reactor. Layered deposits have been produced by pulsing the reactant gases judiciously under software control. The development of a columnar structure which is endemic to most CVD materials has been suppressed. Skeletal structures of filaments have also been grown with appropriate catalysts by the vapor-liquid-solid mechanism and immediately infiltrated in situ with different materials to produce filament-reinforced composite coatings.Ultrafine-grained carbon films and filaments have been grown from methane-hydrogen mixtures by RF plasma-assisted CVD. The microstructural features of these materials are of the order of 20 to 100 nm. The subgrain structure determined by Raman spectroscopy varies from 2 to 3 nm.

TEM characterization of Au/Polysilicon interactions

1990 ◽  
Vol 48 (4) ◽  
pp. 650-651
Author(s):  
N. David Theodore ◽  
Leslie H. Allen ◽  
C. Barry Carter ◽  
James W. Mayer
Keyword(s):  
Solid Phase ◽  
Single Crystal Silicon ◽  
Chemical Vapor ◽  
Electrical Contacts ◽  
Silicon Substrates ◽  
Crystal Silicon ◽  
Transmission Electron ◽  
Polysilicon Films ◽  
The Stability

Metal/polysilicon investigations contribute to an understanding of issues relevant to the stability of electrical contacts in semiconductor devices. These investigations also contribute to an understanding of Si lateral solid-phase epitactic growth. Metals such as Au, Al and Ag form eutectics with Si. reactions in these metal/polysilicon systems lead to the formation of large-grain silicon. Of these systems, the Al/polysilicon system has been most extensively studied. In this study, the behavior upon thermal annealing of Au/polysilicon bilayers is investigated using cross-section transmission electron microscopy (XTEM). The unique feature of this system is that silicon grain-growth occurs at particularly low temperatures ∽300°C).Gold/polysilicon bilayers were fabricated on thermally oxidized single-crystal silicon substrates. Lowpressure chemical vapor deposition (LPCVD) at 620°C was used to obtain 100 to 400 nm polysilicon films. The surface of the polysilicon was cleaned with a buffered hydrofluoric acid solution. Gold was then thermally evaporated onto the samples.

scholarly journals Optical Constant and Conformality Analysis of SiO2 Thin Films Deposited on Linear Array Microstructure Substrate by PECVD

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 510
Author(s):  
Yongqiang Pan ◽  
Huan Liu ◽  
Zhuoman Wang ◽  
Jinmei Jia ◽  
Jijie Zhao
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Deposition Rate ◽  
Optical Constant ◽  
Photoelectron Spectroscopy ◽  
Linear Array ◽  
Chemical Vapor ◽  
Rf Plasma ◽  
X Ray ◽  
Sio2 Thin Film

SiO2 thin films are deposited by radio frequency (RF) plasma-enhanced chemical vapor deposition (PECVD) technique using SiH4 and N2O as precursor gases. The stoichiometry of SiO2 thin films is determined by the X-ray photoelectron spectroscopy (XPS), and the optical constant n and k are obtained by using variable angle spectroscopic ellipsometer (VASE) in the spectral range 380–1600 nm. The refractive index and extinction coefficient of the deposited SiO2 thin films at 500 nm are 1.464 and 0.0069, respectively. The deposition rate of SiO2 thin films is controlled by changing the reaction pressure. The effects of deposition rate, film thickness, and microstructure size on the conformality of SiO2 thin films are studied. The conformality of SiO2 thin films increases from 0.68 to 0.91, with the increase of deposition rate of the SiO2 thin film from 20.84 to 41.92 nm/min. The conformality of SiO2 thin films decreases with the increase of film thickness, and the higher the step height, the smaller the conformality of SiO2 thin films.

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