Ultralow-load indentation hardness and modulus of diamond films deposited by hot-filament-assisted CVD

1990 ◽  
Vol 5 (11) ◽  
pp. 2555-2561 ◽  
Author(s):  
C. P. Beetz ◽  
C. V. Cooper ◽  
T. A. Perry
Keyword(s):  
Diamond Films ◽  
Indentation Hardness ◽  
Thickness Profile ◽  
Average Hardness ◽  
Single Crystal Diamond ◽  
Average Modulus ◽  
Crystallite Sizes ◽  
Simple Exponential Function ◽  
Hot Filament ◽  
Load Indentation

Diamond films, ranging in thickness to approximately 35 μm, were grown on Si(100) substrates using hot-filament-assisted CVD. Two different CH4:H2 ratios were employed during deposition, and the effects on the film morphology and ultralow-load indentation hardness and modulus were investigated. Films deposited from a single, linear filament exhibited a nonuniform deposition thickness profile that can be described by a simple exponential function. Films deposited at lower methane concentrations, 0.11% CH4 in H2, had larger crystallite sizes of ∼5–8 μm, an average hardness of 31 GPa, and an average modulus of 541 GPa. A higher CH4 concentration of 0.99% in H2 resulted in the formation of finer crystallites of approximately 0.5 μm, an average hardness of 65 GPa, and an average modulus of 875 GPa. While these values lie on the low end or outside of the range reported for single crystal diamond, this study has demonstrated that CVD diamond films can be synthesized with ultrahigh or near ultrahigh hardness.

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.

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.

MESFETs on H-terminated Single Crystal Diamond

2009 ◽  
Vol 1203 ◽  
Author(s):  
Paolo Calvani ◽  
Maria Cristina Rossi ◽  
Gennaro Conte ◽  
Stefano Carta ◽  
Ennio Giovine ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Single Crystal ◽  
Oscillation Frequency ◽  
Diamond Films ◽  
Drain Current ◽  
Gate Length ◽  
Maximum Oscillation Frequency ◽  
Single Crystal Diamond ◽  
Device Geometry ◽  
Rf Performance

AbstractEpitaxial diamond films were deposited on polished single crystal Ib type HPHT diamond plates of (100) orientation by microwave CVD. The epilayers were used for the fabrication of surface channel MESFET structures having sub-micrometer gate length in the range 200-800 nm. Realized devices show maximum drain current and trasconductance values of about 190 mA/mm and 80 mS/mm, respectively, for MESFETs having 200 nm gate length. RF performance evaluation gave cut off frequency of about 14 GHz and maximum oscillation frequency of more than 26 GHz for the same device geometry.

Compact and Efficient HFCVD for Electronic Grade Diamond and Related Materials

2009 ◽  
Vol 1203 ◽  
Author(s):  
R. Vispute ◽  
Andrew Seiser ◽  
Geun Lee ◽  
Jaurette Dozier ◽  
Jeremy Feldman ◽  
...  
Keyword(s):  
Diamond Film ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Deposition Efficiency ◽  
Raman Shift ◽  
Compositional Variation ◽  
Force Microscopy ◽  
Substrate Rotation ◽  
Sample Rotation ◽  
Hot Filament

AbstractA compact and efficient hot filament chemical vapor deposition system has been designed for growing electronic-grade diamond and related materials. We report here the effect of substrate rotation on quality and uniformity of HFCVD diamond films on 2” wafers, using two to three filaments with power ranging from 500 to 600 Watt. Diamond films have been characterized using x-ray diffraction, Raman Spectroscopy, scanning electron microscopy and atomic force microscopy. Our results indicate that substrate rotation not only yields uniform films across the wafer, but crystallites grow larger than without sample rotation. Well-faceted microcrystals are observed for wafers rotated at 10 rpm. We also find that the Raman spectrum taken from various locations indicate no compositional variation in the diamond film and no significant Raman shift associated with intrinsic stresses. Results are discussed in the context of growth uniformity of diamond film to improve deposition efficiency for wafer-based electronic applications.

Diamond Films: Recent Developments

MRS Bulletin ◽  
1998 ◽  
Vol 23 (9) ◽  
pp. 16-21 ◽  
Author(s):  
Dieter M. Gruen ◽  
Ian Buckley-Golder
Keyword(s):  
High Temperature ◽  
Integrated Circuits ◽  
Nuclear Power ◽  
Large Scale ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Large Area ◽  
Technical Problems ◽  
Practical Applications ◽  
Single Crystal Diamond

Carbon in the form of diamond is the stuff of dreams, and the image of the diamond evokes deep and powerful emotions in humans. Following the successful synthesis of diamond by high-pressure methods in the 1950s, the startling development of the low-pressure synthesis of diamond films in the 1970s and 1980s almost immediately engendered great expectations of utility. The many remarkable properties of diamond due in part to its being the most atomically dense material in the universe (hardness, thermal conductivity, friction coefficient, transparency, etc.) could at last be put to use in a multitude of practical applications. “The holy grail”—it was realized early on—would be the development of large-area, doped, single-crystal diamond wafers for the fabrication of high-temperature, extremely fast integrated circuits leading to a revolution in computer technology.Excitement in the community of chemical-vapor-deposition (CVD) diamond researchers, funding agencies, and industrial companies ran high in expectation of early realization for many of the commercial goals that had been envisioned: tool, optical, and corrosion-resistant coatings; flat-panel displays; thermomanagement for electronic components, etc. Market projection predicting diamond-film sales in the billions of dollars by the year 2000 was commonplace. Hopes were dashed when these optimistic predictions ran up against the enormous scientific and technical problems that had to be overcome in order for those involved to fully exploit the potential of diamond. This experience is not new to the scientific community. One need only remind oneself of the hopes for cheap nuclear power or for high-temperature superconducting wires available at hardware stores to realize that the lag between scientific discoveries and their large-scale applications can be very long. Diamond films are in fact being used today in commercial applications.

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