Oxidation of diamond films synthesized by hot filament assisted chemical vapor deposition

1990 ◽  
Vol 5 (11) ◽  
pp. 2483-2489 ◽  
Author(s):  
K. Tankala ◽  
T. DebRoy ◽  
M. Alam
Keyword(s):  
Microwave Plasma ◽  
Synthetic Diamond ◽  
Natural Diamond ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Low Oxygen ◽  
Before And After ◽  
Lower Temperature ◽  
Hot Filament

Oxidation of polycrystalline diamond films on (111) Si wafers in air at temperatures up to 1073 K was investigated by thermogravimetry. The diamond films before and after partial oxidation were characterized by optical and scanning electron microscopy, x-ray, infrared, and Raman spectroscopy. The oxidation of synthetic diamond films started at a lower temperature than that for natural diamond. The rates of oxidation of the diamond films synthesized by the hot filament and the microwave plasma methods were intermediate between the rates of oxidation of the 111 and 100 planes of natural diamond crystals. The apparent activation energy for the oxidation of the synthetic diamond films agreed well with that for the oxidation of natural diamond via diamond to graphite transition at low oxygen pressures.

scholarly journals Electrical properties and Mott parameters of polycrystalline diamond films synthesized by HF CVD method from hydrogen/methanol gas mixture

2018 ◽  
Vol 35 (4) ◽  
pp. 830-837 ◽  
Author(s):  
Agnieszka Banaszak-Piechowska ◽  
Kazimierz Fabisiak ◽  
Elżbieta Staryga ◽  
Kazimierz Paprocki
Keyword(s):  
Charge Transport ◽  
Synthetic Diamond ◽  
Electronic Conductivity ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Temperature Dependent ◽  
Cvd Method ◽  
Crystallite Sizes ◽  
Hot Filament

Abstract The influence of diamond crystallinity and preferred orientation on electronic conductivity of synthetic diamond films grown by hot filament chemical vapor deposition (HFCVD) was investigated. The CVD diamond films of different morphologies and crystallite sizes varying from 36 nm to 67 nm, measured in h2 2 0i direction were considered. The charge transport mechanism in the diamond samples was studied using temperature dependent DC conductivity measurements. The obtained results showed that in the temperature range of 90 K to 300 K charge transport is realized via Variable Range Hopping (VRH, m = 1/4) mechanism. Using VRH model, the Mott parameters were evaluated i.e. density of states at Fermi level N(EF) (0.22 × 1015 eV-1·cm-3 to 1.7 × 1015 eV-1·cm-3), hopping energy W (43.5 meV to 142.3 meV) and average hopping distance R (1.49 × 10-5cm to 2.56 × 10-5cm). It was shown that above mentioned parameters strongly depend on diamond film preferential orientation.

Fracture strength measurement of filament assisted CVD polycrystalline diamond films

1992 ◽  
Vol 7 (6) ◽  
pp. 1432-1437 ◽  
Author(s):  
G.F. Cardinale ◽  
C.J. Robinson
Keyword(s):  
Fracture Strength ◽  
Microwave Plasma ◽  
Natural Diamond ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
High Strength ◽  
Coarse Grained ◽  
Diamond Growth ◽  
Growth Surface

The fracture strength of polycrystalline diamond films deposited by filament assisted chemical vapor deposition in the thickness range of 3.5 to 160 μm is investigated. Using a burst pressure technique, the fracture strengths of circular diamond film specimens are calculated. An average fracture strength of 730 MPa for nine samples was computed. This value is in good agreement with published strengths of microwave plasma deposited diamond films, comparable to other high strength materials, and within an order of magnitude of the fracture strength of bulk natural diamond. The average fracture strength of the fine-grained substrate interface appears consistently higher than that of the coarse-grained diamond growth surface.

Examination of the material properties and performance of thin-diamond film cutting tool inserts produced by arc-jet and hot filament chemical vapor deposition

1996 ◽  
Vol 11 (7) ◽  
pp. 1765-1775 ◽  
Author(s):  
James M. Olson ◽  
Michael J. Dawes
Keyword(s):  
Wear Resistance ◽  
Chemical Vapor Deposition ◽  
Diamond Film ◽  
Vapor Deposition ◽  
Cutting Tool ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
And Performance ◽  
Hot Filament

Thin diamond film coated WC-Co cutting tool inserts were produced using arc-jet and hot-filament chemical vapor deposition. The diamond films were characterized using SEM, XRD, and Raman spectroscopy to examine crystal structure, fracture mode, thickness, crystalline orientation, diamond quality, and residual stress. The performance of the tools was evaluated by comparing the wear resistance of the materials to brazed polycrystalline diamond-tipped cutting tool inserts (PCD) while machining A390 aluminum (18% silicon). Results from the experiments carried out in this study suggest that the wear resistance of the thin diamond films is primarily related to the grain boundary strength, crystal orientation, and the density of microdefects in the diamond film.

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.

Characterization of undoped and boron-doped polycrystalline diamond films synthesized by hot-filament chemical vapor deposition using methanol

1994 ◽  
Vol 3 (4-6) ◽  
pp. 618-622 ◽  
Author(s):  
Takashi Sugino ◽  
Kiyoshi Karasutani ◽  
Fumihiro Mano ◽  
Hiroya Kataoka ◽  
Junji Shirafuji ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Boron Doped ◽  
Hot Filament

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.

Synthesis of diamond films on Hastelloy

1992 ◽  
Vol 7 (10) ◽  
pp. 2785-2790 ◽  
Author(s):  
V.P. Godbole ◽  
J. Narayan
Keyword(s):  
Diamond Film ◽  
Composite Layer ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Diamond Growth ◽  
Chemical Vapor Deposition Method ◽  
Nucleation Sites ◽  
Higher Temperature ◽  
Lower Temperature ◽  
Hot Filament

We have developed a two-step hot filament chemical vapor deposition method to form polycrystalline films of diamond on Hastelloy substrates. The first step at a lower temperature results in the deposition of a composite layer of carbon, diamond-like carbon, and diamond, which provide nucleation sites for diamond growth in the second step at a higher temperature. To obtain a cleaner amorphous carbon-free diamond film, we introduced an intermediate hydrogen etching step. Using this procedure, we have obtained high quality polycrystalline diamond film on Hastelloy substrates, as characterized by scanning electron microscopy and Raman measurements.

Electrical Properties of Hydrogen Terminated P-Type Diamond Film

2010 ◽  
Vol 663-665 ◽  
pp. 625-628
Author(s):  
Fu Yuan Xia ◽  
Lin Jun Wang ◽  
Jian Huang ◽  
Ke Tang ◽  
Ji Jun Zhang ◽  
...  
Keyword(s):  
Carrier Concentration ◽  
Microwave Plasma ◽  
Hydrogen Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Plasma Chemical ◽  
Plasma Chemical Vapor Deposition ◽  
P Type ◽  
Effect Method

Undoped high quality polycrystalline diamond films were grown by the microwave plasma chemical vapor deposition (MPCVD) method. The effects of hydrogen plasma treatment and vacuum annealing process on the p-type behavior of diamond films were investigated by the Hall effect method. The sheet carrier concentration increased and the sheet resistivity decreased with the treating time of hydrogen plasma and a stable value was achieved finally. After annealing the samples in vacuum at temperature above 600 °C, the sheet carrier concentration dropped dramatically. The origin of this hydrogen terminated p-type conductive layers is also discussed.

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