EXELFS analysis of natural diamond and diamond films on si substrates

1996 ◽  
Vol 54 ◽  
pp. 556-557
Author(s):  
A. Duarte Moller ◽  
L. Cota Araiza ◽  
M. Avalos Borja
Keyword(s):  
Natural Diamond ◽  
Standard Procedure ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Deposition Process ◽  
Primary Energy ◽  
Acquisition Time ◽  
Ion Milling ◽  
Si Substrates ◽  
Nominal Size

In this work, we report the EXELFS results obtained from a polycrystalline diamond film grown on smooth silicon substrates using the Hot Filament Chemical Vapor Deposition (HF-CVD) technique in a two-step deposition process published elsewhere. In order to evaluate the quality of the thin film obtained, these results were compared with results obtained from natural diamond. The diamond sample was prepared in cross-section by ion milling where the nominal size of diamond.particles was about 1 μn. The EXELFS experiments were performed in a JEOL-2010 Transmission Electron Microscope with a GATAN-666 PEELS attachment. A primary energy of 200 KeV was used with an average acquisition time of 5 minutes. The extended fine structure (EFS) energy range was 300 eV. In order to obtain the local structure, the standard procedure developed for EXAFS was applied here. The natural diamond particles with a nominal size of 1 μn were taken from commercial powder.

scholarly journals Effect of Substrate Holder Design on Stress and Uniformity of Large-Area Polycrystalline Diamond Films Grown by Microwave Plasma-Assisted CVD

Coatings ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 939
Author(s):  
Vadim Sedov ◽  
Artem Martyanov ◽  
Alexandr Altakhov ◽  
Alexey Popovich ◽  
Mikhail Shevchenko ◽  
...  
Keyword(s):  
Microwave Plasma ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Deposition Process ◽  
Laser Flash ◽  
The Novel ◽  
Substrate Holder ◽  
Large Area ◽  
Si Substrates ◽  
Laser Flash Technique

In this work, the substrate holders of three principal geometries (flat, pocket, and pedestal) were designed based on E-field simulations. They were fabricated and then tested in microwave plasma-assisted chemical vapor deposition process with the purpose of the homogeneous growth of 100-μm-thick, low-stress polycrystalline diamond film over 2-inch Si substrates with a thickness of 0.35 mm. The effectiveness of each holder design was estimated by the criteria of the PCD film quality, its homogeneity, stress, and the curvature of the resulting “diamond-on-Si” plates. The structure and phase composition of the synthesized samples were studied with scanning electron microscopy and Raman spectroscopy, the curvature was measured using white light interferometry, and the thermal conductivity was measured using the laser flash technique. The proposed pedestal design of the substrate holder could reduce the stress of the thick PCD film down to 1.1–1.4 GPa, which resulted in an extremely low value of displacement for the resulting “diamond-on-Si” plate of Δh = 50 μm. The obtained results may be used for the improvement of already existing, and the design of the novel-type, MPCVD reactors aimed at the growth of large-area thick homogeneous PCD layers and plates for electronic applications.

Electrical Properties of Thin Film and Bulk Diamond Treated in Hydrogen Plasma

1989 ◽  
Vol 162 ◽  
Author(s):  
Sacharia Albin ◽  
Linwood Watkins
Keyword(s):  
Natural Diamond ◽  
Hydrogen Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Silicon Substrates ◽  
Free Standing ◽  
Before And After ◽  
Type Ia ◽  
Bulk Diamond

ABSTRACTCurrent-voltage characteristics of type Ia synthetic diamond, type IIb natural diamond and free-standing diamond films were measured before and after hydrogenation. The diamond films were polycrystalline, deposited on sacrificial silicon substrates using a microwave chemical vapor deposition process. On hydrogenation, all the samples showed several orders of magnitude increase in conductivity. Hydrogenation was carried out under controlled conditions to study the changes in the I-V characteristics of the samples. The concentration of electrically active hydrogen was determined from the I-V data. Hydrogen passivation of deep traps in diamond is clearly demonstrated.

The Control Of Intrinsic Stresses In Cvd Diamond Films With Multistep Processing

1995 ◽  
Vol 416 ◽  
Author(s):  
S. Nijhawan ◽  
S. M. Jankovsky ◽  
B. W. Sheldon
Keyword(s):  
Thermal Stresses ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Annealing Treatment ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Internal Stresses ◽  
Tensile Stresses ◽  
Si Substrates

ABSTRACTThe role of intrinsic stresses in diamond films is examined. The films were deposited on (100) Si substrates by microwave plasma-enhanced chemical vapor deposition. The total internal stresses (thermal and intrinsic) were measured at room temperature with the bending plate method. The thermal stresses are compressive and arise due to the mismatch in thermal expansion coefficient of film and substrate. The intinsic stresses were tensile and evolved during the deposition process. These stresses increased with increasing deposition time. A 12 hour intermediate annealing treatment was found to reduce the tensile stresses considerably. The annealing treatment is most effective when the diamond crystallites are undergoing impingement and coalescence. This is consistent with the theory that the maximum tensile stresses are associated with grain boundary energetics.

Effects of Various Seeding Methods on Multi-Layered Diamond Coatings Deposited via Hot Filament Chemical Vapor Deposition

2013 ◽  
Vol 845 ◽  
pp. 36-40
Author(s):  
Tze Mi Yong ◽  
Esah Hamzah
Keyword(s):  
Natural Diamond ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Columnar Structure ◽  
X Rays ◽  
Diamond Coating ◽  
Diamond Coatings ◽  
Good Adhesion ◽  
Hot Filament ◽  
Xrd Method

Multi-layer alternating nanocrystalline diamond (NCD) layer and polycrystalline diamond (PCD) layer was successfully deposited on pretreated tungsten carbide (WC) substrates with various seeding sizes (<0.1μm synthetic, <0.5μm synthetic, <0.25μm natural, <0.5μm natural, and <1μm natural) diamond with and without hammering by silicon carbide. X-rays penetrate through the coating to the substrate from XRD method was able to show strong peaks of diamond relative to WC despite the diamond film being 4μm thick only. It is found that substrates with no hammering produce stronger signals. The coating was cross sectioned and analysed using field emission scanning electron microscopy showing the multi-layer with NCD grains that has coalesced and columnar structure for PCD. None of the diamond coating delaminated during cross sectioning showing good adhesion. Raman was able to capture data from the 1-1.6μm thick NCD layer only while AFM measured the extreme low roughness of the NCD surface.

Low-Cost Sputtering Process for Carbon Nanotubes Synthesis

2019 ◽  
Vol 891 ◽  
pp. 195-199
Author(s):  
Theerapol Thurakitseree ◽  
Chupong Pakpum
Keyword(s):  
Carbon Nanotubes ◽  
Low Cost ◽  
Chemical Vapor ◽  
Thin Film Deposition ◽  
Deposition Process ◽  
Film Deposition ◽  
Synthesis Process ◽  
Metal Thin Films ◽  
Si Substrates ◽  
Custom Made

According to their wonderful properties, carbon nanotubes (CNTs) have been well known for decades. The synthesis process and catalyst deposition method have also drawn attention to control the nanotube structure and properties. Sputtering method is then one promising option to grow the nanotubes in mass production. This method is, however, still costly. Here, we have presented a simple low-cost custom-made DC magnetron sputtering for catalyst thin film deposition. Three different metal thin films (Fe, Ni, Cu) deposited on Si substrates have been employed to investigate nanotube production. Prior to deposition of the catalysts, Al was used as supporting layer. (Al/Fe, Al/Ni, Al/Cu). CNTs were grown by chemical vapor deposition process at 800°C. Ethanol was preliminary used as a carbon source. It was found that CNTs could be successfully grown from only Al/Ni catalysts in our system with the diameter of approximately 200 nm, where the rest of samples were not observed. In addition, vertical-aligned CNTs with the thickness of about 10 μm could be obtained when acetylene was replaced instead of ethanol with reducing partial pressure of the feedstock. A large D-band at 1338 cm-1 with broader G-band at 1582 cm-1 from Raman spectra give a rise to multi layers growth of sp2 carbon walls. Such dimension suggests that it is the characteristic of multi-walled carbon nanotubes.

Effect of Mechanical Stress on Polycrystalline Diamond Schottky Diode I-V Characteristics

1992 ◽  
Vol 270 ◽  
Author(s):  
G. Zhao ◽  
E. M. Charlson ◽  
E. J. Charlson ◽  
T. Stacy ◽  
J. Meese ◽  
...  
Keyword(s):  
Mechanical Stress ◽  
Schottky Diodes ◽  
Forward Bias ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Deposition Process ◽  
Stress Sensitivity ◽  
Stress Effect ◽  
Mechanical Sensors ◽  
Hot Filament

ABSTRACTSchottky diodes to be used for mechanical stress effect studies were fabricated using aluminum contacts to polycrystalline diamond thin films grown by a hot-filament assisted chemical vapor deposition process. Compressive stress was found to have a large effect on the forward biased current-voltage characteristics of the diode. At selected values of constant forward biased current, a linear relationship between voltage and stress, for stress less than 10 N was observed. The stress sensitivity of the diode was as high as 0.74 V/N at 1 mA forward bias. This study shows that polycrystalline diamond Schottky diodes are stress sensitive devices and have potential as mechanical sensors.

Study and Application on CVD Diamond Tools

2006 ◽  
Vol 315-316 ◽  
pp. 720-724 ◽  
Author(s):  
Tie Fu ◽  
Qi Xun Yu ◽  
Si Qin Pang
Keyword(s):  
Natural Diamond ◽  
Cutting Tools ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Cvd Diamond ◽  
Hot Press ◽  
Diamond Cutting ◽  
Diamond Cutting Tools ◽  
Mechanical And Physical Properties ◽  
Machining Test

Diamond film made by adopting the Chemical Vapor Deposition (CVD) technology is a promising superhard material. The mechanical and physical properties of CVD diamond is between natural diamond and hot press polycrystalline diamond. The cutting tools made by CVD diamond can machine many kinds of material, such as nonferrous metals, non metallic materials and composites. CVD diamond is classified as thin and thick films, and the thick film cutting tools are widely used. However, the superhard cutting tools cannot be applied to the cutting of iron family metal and molybdenum (Mo). In this paper, data and curves on machining test of CVD diamond cutting tools are listed and then analyzed.

scholarly journals Fabrication of Si3N4Nanocrystals and Nanowires Using PECVD

2010 ◽  
Vol 2010 ◽  
pp. 1-4 ◽  
Author(s):  
Jingwei Song ◽  
Xiying Ma ◽  
Wang Zui ◽  
Chen Wei ◽  
Zhongpin Chen
Keyword(s):  
Chemical Vapor Deposition ◽  
Growth Mechanism ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Si Substrates ◽  
Fe Catalyst ◽  
Reactive Gases ◽  
Fe Ions ◽  
S Deposition

Si3N4nanowires and nanocrystals were prepared on Si substrates with or without Fe catalyst using silane (SiH4) and nitrogen (N2) as reactive gases through plasma-enhanced chemical vapor deposition (PECVD) technology. With Fe catalyst,Si3N4nanowires were developed, indicating that Fe catalyst played a role forSi3N4molecules directionally depositing into strings. The density of the nanowires is closely related to the density of Fe catalyst. When the density of Fe ions on the substrate was decreased remarkably, a smooth superlongSi3N4nanowire with 12 μm in length was fabricated. Having analyzed the growth mechanism, a growth model forSi3N4nanowires was developed. The growth ofSi3N4nanocrystallines was attributed to be a vapor-solid (V-S) deposition process.

scholarly journals Improving Pressure–Velocity Limit of Mechanical Seal with Polycrystalline Diamond Coating

2020 ◽  
Vol 10 (17) ◽  
pp. 6090
Author(s):  
Daidong Guo ◽  
Ningning Cai ◽  
Guoping Wu ◽  
Fangmin Xie ◽  
Shouhong Tan ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Deposition Process ◽  
Operating Conditions ◽  
Mechanical Seal ◽  
Initial Deposition ◽  
Hot Filament ◽  
Harsh Conditions ◽  
Sintered Silicon

Polycrystalline diamond (PCD)-coated mechanical seal rings were prepared by hot filament chemical vapor deposition (HFCVD) on graphite-loaded silicon carbide (GSiC) substrates. From the initial deposition process, the diamond first nucleated and then grew into a dense coating with grain size of 4 μm and thickness of 12.3 μm. The well-grown PCD coating, as confirmed by Raman spectroscopy and X-ray diffractometry, significantly improves the pressure–velocity limit of the mechanical seal applied in harsh operating conditions, no matter whether for a hard-to-soft mating combination or a hard-to-hard mating combination. Comparing GSiC against sintered silicon carbide (SSiC) combination (GSiC/SSiC), GSiC against graphite combination (GSiC/graphite) and PCD against graphite combination (PCD/graphite), PCD against SSiC combination (PCD/SSiC) shows the highest pressure velocity (PV) limit of 42.31 MPa·m/s with 4 kN loading at 4500 rpm rotation speed. An extremely low and stable friction coefficient and super mechanical properties under harsh conditions can be approved as the source of the high PV limit of PCD coating. A mechanical seal with PCD coating can be used for more demanding applications.

A Novel Ruthenium Precursor for MOCVD without Seed Ruthenium Layer

2002 ◽  
Vol 748 ◽  
Author(s):  
Tetsuo Shibutami ◽  
Kazuhisa Kawano ◽  
Noriaki Oshima ◽  
Shintaro Yokoyama ◽  
Hiroshi Funakubo
Keyword(s):  
Vapor Deposition ◽  
Deposition Temperature ◽  
Metalorganic Chemical Vapor Deposition ◽  
Single Phase ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Decomposition Temperature ◽  
Liquid Precursor ◽  
Si Substrates ◽  
Initial Nucleation

ABSTRACTRuthenium thin films were deposited on SiO2/Si substrates at 275 – 400 °C by metalorganic chemical vapor deposition (MOCVD) using liquid precursor (2.4-dimethylpentadienyl)(ethylcyclopentadienyl)ruthenium [Ru(DMPD)(EtCp) DMPD: 2.4-dimethylpentadienyl EtCp: etylcyclopentadienyl]. Deposition characteristics of the films were compared with those using bis(ethylcyclopentadienyl)ruthenium.The decomposition temperature of Ru(DMPD)(EtCp) was 80 °C lower than Ru(EtCp)2. Both films consisted of Ru single phase for all deposition temperature range and showed an resistivity bellow 20 μΩcm for the films deposited above 300 °C. The initial nucleation of Ru films from Ru(DMPD)(EtCp) precursor was smaller in size and denser than that from Ru(EtCp)2. The deposition process from Ru(DMPD)(EtCp) has much shorter incubation time than that from Ru(EtCp)2.

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