Influence of post-annealing on a diamondlike carbon film analyzed by Raman spectroscopy

2018 ◽  
Vol 50 (4) ◽  
pp. 441-447 ◽  
Author(s):  
Susumu Takabayashi ◽  
Keishi Okamoto ◽  
Tatsuyuki Nakatani
Keyword(s):  
Raman Spectroscopy ◽  
Carbon Film ◽  
Post Annealing ◽  
Diamondlike Carbon

Evaluation of DLC Coatings for High-Temperature Foil Bearing Applications

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Said Jahanmir ◽  
Hooshang Heshmat ◽  
Crystal Heshmat
Keyword(s):  
Carbon Film ◽  
Dlc Coatings ◽  
Foil Bearings ◽  
Dlc Coating ◽  
Foil Bearing ◽  
Flat Disk ◽  
Wide Range ◽  
Diamondlike Carbon ◽  
Powder Lubrication ◽  
Foil Thrust Bearing

Diamondlike carbon (DLC) coatings, particularly in the hydrogenated form, provide extremely low coefficients of friction in concentrated contacts. The objective of this investigation was to evaluate the performance of DLC coatings for potential application in foil bearings. Since in some applications the bearings experience a wide range of temperatures, tribological tests were performed using a single foil thrust bearing in contact with a rotating flat disk up to 500°C. The coatings deposited on the disks consisted of a hydrogenated diamondlike carbon film (H-DLC), a nonhydrogenated DLC, and a thin dense chrome deposited by the Electrolyzing™ process. The top foil pads were coated with a tungsten disulfide based solid lubricant (Korolon™ 900). All three disk coatings provided excellent performance at room temperature. However, the H-DLC coating proved to be unacceptable at 300°C due to lack of hydrodynamic lift, albeit the very low coefficient of friction when the foil pad and the disk were in contact during stop-start cycles. This phenomenon is explained by considering the effect of atmospheric moisture on the tribological behavior of H-DLC and using the quasihydrodynamic theory of powder lubrication.

Temperature and Water Vapor Pressure Effects on the Friction Coefficient of Hydrogenated Diamondlike Carbon Films

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Pamela L. Dickrell ◽  
N. Argibay ◽  
Osman L. Eryilmaz ◽  
Ali Erdemir ◽  
W. Gregory Sawyer
Keyword(s):  
Water Vapor ◽  
Friction Coefficient ◽  
Vapor Pressure ◽  
Water Vapor Pressure ◽  
Carbon Film ◽  
Transient Behavior ◽  
Carbon Films ◽  
Pressure Effects ◽  
Diamondlike Carbon ◽  
Gas Surface Interactions

Microtribological measurements of a hydrogenated diamondlike carbon film in controlled gaseous environments show that water vapor plays a significant role in the friction coefficient. These experiments reveal an initial high friction transient behavior that does not reoccur even after extended periods of exposure to low partial pressures of H2O and O2. Experiments varying both water vapor pressure and sample temperature show trends of a decreasing friction coefficient as a function of both the decreasing water vapor pressure and the increasing substrate temperature. Theses trends are examined with regard to first order gas-surface interactions. Model fits give activation energies on the order of 40 kJ/mol, which is consistent with water vapor desorption.

scholarly journals Thermal Annealing of High Dose P Implantation in 4H-SiC

2019 ◽  
Vol 963 ◽  
pp. 399-402 ◽  
Author(s):  
Cristiano Calabretta ◽  
Massimo Zimbone ◽  
Eric G. Barbagiovanni ◽  
Simona Boninelli ◽  
Nicolò Piluso ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Raman Spectroscopy ◽  
Ion Implantation ◽  
Epitaxial Layer ◽  
Point Defects ◽  
High Dose ◽  
Double Step ◽  
Post Annealing ◽  
Transmission Electron

In this work, we have studied the crystal defectiveness and doping activation subsequent to ion implantation and post-annealing by using various techniques including photoluminescence (PL), Raman spectroscopy and transmission electron microscopy (TEM). The aim of this work was to test the effectiveness of double step annealing to reduce the density of point defects generated during the annealing of a P implanted 4H-SiC epitaxial layer. The outcome of this work evidences that neither the first 1 hour isochronal annealing at 1650 - 1700 - 1750 °C, nor the second one at 1500 °C for times between 4 hour and 14 hour were able to recover a satisfactory crystallinity of the sample and achieve dopant activations exceeding 1%.

Production and Characterization of Carbon Thin Films by the Magnetron Sputtering Technique

2016 ◽  
Vol 881 ◽  
pp. 471-474 ◽  
Author(s):  
D.L.C. Silva ◽  
L.R.P Kassab ◽  
J.R. Martinelli ◽  
A.D. Santos ◽  
M.F. Pillis
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Magnetron Sputtering ◽  
Carbon Film ◽  
Carbon Films ◽  
Buffer Layers ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Carbon Thin Films

Carbon thin films were produced by the magnetron sputtering technique. The deposition of the carbon films was performed on Co buffer-layers previously deposited on c-plane (0001) sapphire substrates. The samples were thermally treated under vacuum conditions and characterized by Raman spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The XRD peak related to the carbon film was observed and the Raman spectroscopy indicated a good degree of crystallinity of the carbon film.

Influence of P+-Implantation and Post-Annealing on Warpage Structure of 4H-SiC Wafers

2014 ◽  
Vol 778-780 ◽  
pp. 449-452 ◽  
Author(s):  
Kotaro Ishiji ◽  
Seiji Kawado ◽  
Yasuharu Hirai ◽  
Shinji Nagamachi
Keyword(s):  
Raman Spectroscopy ◽  
Crystal Plane ◽  
X Ray ◽  
Lattice Disorder ◽  
Annealing Temperatures ◽  
Post Annealing ◽  
The Relationship ◽  
Monochromatic Synchrotron

We examined the warpage structure in epitaxial 4H-SiC wafers subjected to phosphorus-ion (P+) implantation and post-annealing with varying implantation and annealing temperatures, using glazing-incidence monochromatic synchrotron X-ray topography. Using Raman spectroscopy, we then studied the relationship between the warpage of the crystal plane in the underlying epilayer and the recovery of lattice disorder in the implanted layer. We determined that the warpage structure of the underlying SiC epilayer was closely correlated with the recovery of lattice disorder in the implanted layer.

scholarly journals Structure of Carbonic Layer in Ohmic Contacts: Comparison of Silicon Carbide/Carbon and Carbon/Silicide Interfaces

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Paweł Borowicz ◽  
Adrian Kuchuk ◽  
Zbigniew Adamus ◽  
Michał Borysiewicz ◽  
Marek Ekielski ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Raman Spectroscopy ◽  
Thermal Treatment ◽  
Ohmic Contacts ◽  
Carbon Film ◽  
Graphene Layers ◽  
Three Samples ◽  
Nickel Silicon

The structure of carbonic layer in three samples composed of 4H polytype of silicon carbide and the following sequence of layers: carbon/nickel/silicon/nickel/silicon was investigated with Raman spectroscopy. Different thermal treatment of the samples led to differences in the structure of carbonic layer. Raman measurements were performed with visible excitation focused on two interfaces: silicon carbide/carbon and carbon/silicide. The results showed differences in the structure across carbon film although its thickness corresponds to 8/10 graphene layers.

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