Microstructure of polycrystalline diamond film

1990 ◽  
Vol 48 (4) ◽  
pp. 708-709
Author(s):  
M. G. Burke ◽  
R. E. Witkowski ◽  
R. T. Blackham
Keyword(s):  
Electron Microscopy ◽  
Diamond Film ◽  
Microwave Plasma ◽  
Plasma Deposition ◽  
Analytical Electron Microscopy ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Optical Systems ◽  
Power Sources

Diamond films have attracted considerable attention for use in a wide variety of industrial and commercial applications, particularly as coatings. Diamond coatings will enhance the performance of electro-optical systems, space-based photovoltaic power sources, packages for power electronic devices, and wear-limited processing equipment. These films are generally grown via plasma deposition or chemical vapor deposition techniques using a mixture. To characterize the as-grown diamond films, a variety of techniques including transmission electron microscopy are utilized. For this study, films were grown in a 1.5 kW ASTeX High Pressure Microwave Plasma Source equipped with an austenitic stainless steel, quartz lined reaction chamber. The plasma was a mixture of 0.5 or 2.0% CH4 in H2 at a reactor pressure of 30-50 mm Hg. During deposition, the substrate was heatea to ∼900-950°C. It has been reported that variations in the growth conditions will markedly affect the microstructure of the diamond film; several film morphologies have been observed. The quality of the substrate also exerts a strong effect on the nucleation of the diamond. In this on-going study, the influence of film thickness on the microstructure of polycrystalline diamond films has been characterized by analytical electron microscopy.

Characterization of homoepitaxial diamond films by Electron microscopy

1991 ◽  
Vol 49 ◽  
pp. 880-881
Author(s):  
D.P. Malta ◽  
S.A. Willard ◽  
R.A. Rudder ◽  
G.C. Hudson ◽  
J.B. Posthill ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Surface Defects ◽  
Substrate Surface ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Large Degree ◽  
Rf Plasma ◽  
Semiconducting Diamond

Semiconducting diamond films have the potential for use as a material in which to build active electronic devices capable of operating at high temperatures or in high radiation environments. A major goal of current device-related diamond research is to achieve a high quality epitaxial film on an inexpensive, readily available, non-native substrate. One step in the process of achieving this goal is understanding the nucleation and growth processes of diamond films on diamond substrates. Electron microscopy has already proven invaluable for assessing polycrystalline diamond films grown on nonnative surfaces.The quality of the grown diamond film depends on several factors, one of which is the quality of the diamond substrate. Substrates commercially available today have often been found to have scratched surfaces resulting from the polishing process (Fig. 1a). Electron beam-induced current (EBIC) imaging shows that electrically active sub-surface defects can be present to a large degree (Fig. 1c). Growth of homoepitaxial diamond films by rf plasma-enhanced chemical vapor deposition (PECVD) has been found to planarize the scratched substrate surface (Fig. 1b).

Nano-Crystalline Diamond Films Deposited on Copper Substrate by MPCVD Method

2011 ◽  
Vol 117-119 ◽  
pp. 1310-1314
Author(s):  
Xing Rui Li ◽  
Xin Wei Shi ◽  
Ning Yao ◽  
Xin Chang Wang
Keyword(s):  
Diamond Film ◽  
Deposition Time ◽  
Microwave Plasma ◽  
Copper Substrate ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Annealing Process ◽  
Adhesive Properties ◽  
Plasma Chemical Vapor Deposition ◽  
Nano Crystalline

Nano-crystalline diamond (NCD) films with good adhesion were deposited on flexible copper substrate with Ni interlayer by Microwave Plasma Chemical Vapor Deposition (MPCVD). In this paper, two-stage method was used to improve the adhesion between the copper substrates and the diamond films. The effect of deposition time of the first stage on the morphology, crystal structure, non-diamond phase and adhesive properties of diamond films was investigated. The performance and structure of the diamond films were studied by Scanning Electron Microscope (SEM), Raman Spectroscopy (Raman) and X-Ray Diffraction (XRD). The results showed that the films were nano-crystalline diamond films positively. Impress method was used to examine the adhesion between diamond film and the substrate. When deposition time is 1.5h, the adhesion between diamond film and the copper substrate is better than the others. When it was 2.5h or longer, because the graphite layers existed as intermediate, the adherence between the diamond films and copper substrates was very poor. Therefore, the diamond films were easily peeled off from the substrates. Otherwise, the second stage called annealing process after the deposition played an important role to the adhesion. The films would be easily peeled off by curling without the annealing process.

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.

A Study of the Origin of Band-A Emission in Homoepitaxial Diamond Thin Films

1999 ◽  
Vol 588 ◽  
Author(s):  
Daisuke Takeuchi ◽  
Hideyuki Watanabe ◽  
Sadanori Yamanaka ◽  
Hideyo Okushi ◽  
Koji Kajimura ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Grain Boundaries ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Plasma Chemical Vapor Deposition ◽  
Transmission Electron ◽  
Excitonic Emission

AbstractThe band-A emission (around 2.8 eV) observed in high quality (device-grade) homoepitaxial diamond films grown by microwave-plasma chemical vapor deposition (CVD) was studied by means of scanning cathodoluminescence spectroscopy and high-resolution transmission electron microscopy. Recent progress in our study on homoepitaxial diamond films was obtained through the low CH4/H2 conditions by CVD. These showed atomically flat surfaces and the excitonic emission at room temperature, while the band-A emission (2.95 eV) decreased. Using these samples, we found that the band-A emission only appeared at unepitaxial crystallites (UC) sites, while other flat surface parts still showed the excitonic emission. High-resolution transmission electron microscopy revealed that there were grain boundaries which contained π-bonds in UC. This indicates that one of the origin of the band-A emission in diamond films is attributed to π bonds of grain boundaries.

High Resolution Tem Study of Diamond Formation on Silicon and Molybdenum Field Emitter Surfaces

1994 ◽  
Vol 354 ◽  
Author(s):  
A. F. Myers ◽  
J. Liu ◽  
W. B. Choi ◽  
G. J. Wojak ◽  
J. J. Hren
Keyword(s):  
High Resolution ◽  
Diamond Film ◽  
Microwave Plasma ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Plasma Chemical Vapor Deposition ◽  
Field Emitters ◽  
High Resolution Tem ◽  
Diffraction Patterns ◽  
Polycrystalline Diamond Film

AbstractDiamond is an attractive material for coating microfabricated metal and semiconductor field emitters, since it enhances the stability and emission characteristics of the emitter. In the present study, polycrystalline diamond thin films were grown on silicon and molybdenum field emitters by microwave plasma chemical vapor deposition, using the bias-enhanced nucleation technique. High resolution transmission electron microscopy (TEM) was used to analyze the morphology of the diamond film and the structure of the diamond/emitter interface. Electron diffraction patterns and high resolution images indicate the presence of a polycrystalline diamond film, as well as a polycrystalline SiC layer between the diamond film and the Si emitter. A carbide interlayer was also found to exist between the diamond and the Mo emitter surface. Parallel electron energy loss spectroscopy confirms the TEM identification of a polycrystalline diamond film.

Microcrystalline and Nanocrystalline Diamond Film Deposition on Cobalt Chrome Alloy

1999 ◽  
Vol 594 ◽  
Author(s):  
Marc D. Fries ◽  
Yogesh K. Vohra
Keyword(s):  
Diamond Film ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Film Deposition ◽  
Nanocrystalline Diamond ◽  
Plasma Chemical Vapor Deposition ◽  
High Thermal Expansion ◽  
Cobalt Chrome Alloy ◽  
Cobalt Chrome

AbstractThe cobalt chrome alloy Co-28Cr-6Mo is widely used in human joint replacement applications. These joints are highly sensitive to wear and are usually replaced after approximately ten years of use. In order to extend these implants' service lifetimes, a thin film of diamond may be applied to the implant wear surfaces by microwave plasma chemical vapor deposition (MPCVD) following MPCVD nitridation. Diamond films often delaminate from cobalt chrome due to a high thermal expansion mismatch. Additionally, under most conditions diamond films degrade into graphite by dissolution of nuclei into solvents like Co and Cr. By nitriding the cobalt chrome through MPCVD prior to diamond deposition, a usable diamond film may be achieved. It may be possible to merge both the nitriding and deposition steps into a single process, since both nitridation and deposition will be performed by MPCVD. In addition, controlled amounts of nitrogen in hydrogen/methane plasma under CVD conditions result in a nanostructured diamond coating. We have investigated the formation of both micro- and nanocrystalline diamond formation on cobalt chrome.

Comparative fractography of chemical vapor and combustion deposited diamond films

1990 ◽  
Vol 5 (11) ◽  
pp. 2572-2588 ◽  
Author(s):  
H. A. Hoff ◽  
A. A. Morrish ◽  
J. E. Butler ◽  
B. B. Rath
Keyword(s):  
Electron Microscopy ◽  
Diamond Films ◽  
Stacking Faults ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Ambient Atmosphere ◽  
Transmission Electron ◽  
Controlled Environments ◽  
Inherent Strength ◽  
Low Pressures

Polycrystalline diamond films of several thicknesses have been fractured by manual bending and examined by scanning electron microscopy. These films have been deposited in controlled environments at low pressures by chemical vapor deposition and in ambient atmosphere with an oxygen-acetylene torch. Fracture surfaces in the low pressure depositions exhibit cleavage steps across the grains. These surfaces, independent of thickness, are primarily transgranular, attesting to the inherent strength of the deposits. However, the ambient deposited diamond has primarily intergranular fracture indicative of weak grain boundaries. Internal defects, observed with transmission electron microscopy, such as twins, stacking faults, and dislocations, occur generally in both types of deposition with no apparent preference for location or type of deposition.

Polycrystalline Diamond Film Resistors

1992 ◽  
Vol 242 ◽  
Author(s):  
L. M. Edwards ◽  
J. L. Davidson
Keyword(s):  
Diamond Film ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Polycrystalline Diamond ◽  
Plasma Cvd ◽  
Microwave Plasma Cvd ◽  
P Type ◽  
Polycrystalline Diamond Film ◽  
Effective Source

ABSTRACTThe technology to fabricate polycrystalline diamond film resistors has been initiated using modified thick film patterning techniques and in situ solid source doping.Doping of polycrystalline diamond films in microwave plasma CVD systems has been achieved historically through use of diborane gas, which may contaminate the deposition system causing all diamond films thereafter to be doped p-type. We have attempted noncontaminating in situ doping utilizing two solid source dopants, and have met with preliminary success.The more effective source (B2O3) produces a fairly even dopant concentration across the substrate, with sheet resistances ranging from 800 ohms per square to 4500 ohms per square. The other source (BN) showed significant doping in a narrow band surrounding the source, but the doping concentration decreased rapidly with distance from the source. Films grown afterwards with no doping were evaluated through resistance measurements; no evidence of doping contamination was observed.

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