Diamond Growth on (a) Large Mo Cylinders at 30 Torr and (b) Flat Mo at One Atmospheric Pressure of H2 and CH4

1996 ◽  
Vol 441 ◽  
Author(s):  
R. Ramesham ◽  
M. F. Rose
Keyword(s):  
Atmospheric Pressure ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Polycrystalline Diamond ◽  
Diamond Growth ◽  
Single Filament ◽  
Active Length ◽  
Microwave Plasma Cvd ◽  
Hot Filament ◽  
First Time

Abstract(a) Polycrystalline diamond films have been grown on cylindrical Mo substrates by hot filament and microwave plasma CVD techniques using a gas mixture of hydrogen and methane. A single hot tungsten filament has been used to demonstrate the growth of adherent diamond films on large cylinders. To our knowledge this is the first report on such large cylindrical substrate (area: 41 cm2 ) using a single filament of active length of 3.75 cm. (b) Polycrystalline diamond films have been deposited by hot-filament technique for the first time using methane and hydrogen at an atmospheric pressure of hydrogen on flat substrates. The diamond growth has been performed at various pressures ranging from 34.5 to 750 Torr. The as-deposited films were analyzed by SEM and Raman to determine morphology and chemical nature, respectively.A. Growth of Diamond Film on Molybdenum Cylinders

Diamond Growth Chemistry During Atmospheric-Pressure Plasma Cvd

1995 ◽  
Vol 416 ◽  
Author(s):  
S. L. Girshick ◽  
J. W. Lindsay
Keyword(s):  
Atmospheric Pressure ◽  
Linear Growth ◽  
Diamond Films ◽  
Atmospheric Pressure Plasma ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Diamond Growth ◽  
Gas Chromatograph ◽  
Plasma Cvd ◽  
Flow Geometry

ABSTRACTDiamond films were deposited by chemical vapor deposition using a radio- frequency induction plasma operating at 130 torr. Linear growth rates of polycrystalline diamond films ranged from 18 to 37 μm h-1. For a fixed substrate temperature of 1000°C the input methane-hydrogen ratio was varied from 2% to 10%. Over this range the resulting film morpologies changed from faceted ball-like structures to well-faceted diamond, then to non-faceted balls, and for the well- faceted films increases in methane-hydrogen ratio caused the film texture to shift toward the <100> direction. During these experiments gas sampled through an orifice in the center of the substrate was delivered to a gas chromatograph for measurement of stable hydrocarbon species. As the input methane-hydrogen ratio was increased the measured methane-acetylene ratio decreased. The gas chromatograph measurements showed marked differences from measurements made for an RF reactor with somewhat different flow geometry operating at atmospheric pressure.

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.

Comparative measurements of acceptor concentration at the growth and nucleation side of microwave plasma CVD polycrystalline diamond films

2003 ◽  
Vol 12 (3-7) ◽  
pp. 531-537 ◽  
Author(s):  
V.G. Ralchenko ◽  
Y.V. Pleskov ◽  
V.I. Polyakov ◽  
A.V. Khomich ◽  
Y.E. Evstefeeva ◽  
...  
Keyword(s):  
Microwave Plasma ◽  
Diamond Films ◽  
Polycrystalline Diamond ◽  
Plasma Cvd ◽  
Acceptor Concentration ◽  
Microwave Plasma Cvd

Selective Growth of Polycrystalline Diamond Thin Films

1992 ◽  
Vol 282 ◽  
Author(s):  
R. Ramesham
Keyword(s):  
Plasma Etching ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Polycrystalline Diamond ◽  
Selective Growth ◽  
Diamond Growth ◽  
Nucleation Density ◽  
Substrate Type ◽  
Temperature Growth ◽  
Single Crystal Diamond

ABSTRACTMicrowave plasma assisted CVD is employed to grow diamond films using a gas mixture of H2 and CH4on various substrates. Diamond has a tendency not to nucleate growth on mirror-smooth finished substrates irrespective of the substrate type (except single crystal diamond). We have developed various processes to enhance the nucleation density of the diamond substantially by damaging or seeding the surface of the substrates. Several process techniques such as 1. silicon nitride and silicon dioxide process, 2. ultrasonic agitation process, 3. selective seeding of diamond by electroplating of Cu, 4. patterning of diamond films by air-microwave plasma etching, etc., were developed to achieve the patterns of diamond on various substrates. Selective growth of doped diamond and low temperature growth of diamond for microelectronic applications have also been achieved by using the above processes (1 and 2). Details on selective diamond growth processes and the morphology of as-deposited selective diamond by SEM are presented.

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.

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.

Promoting secondary nucleation using methane modulations during diamond chemical vapor deposition to produce smoother, harder, and better quality films

2003 ◽  
Vol 18 (2) ◽  
pp. 296-304 ◽  
Author(s):  
N. Ali ◽  
V.F. Neto ◽  
J. Gracio
Keyword(s):  
Growth Rate ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Plasma Cvd ◽  
Secondary Nucleation ◽  
Microwave Plasma Cvd ◽  
Hot Filament Cvd ◽  
Hot Filament

In this paper, we present results obtained from a comparison study relating to the deposition of diamond films using two processes, namely, time-modulated chemical vapor deposition (TMCVD) and conventional CVD. Polycrystalline diamond films were deposited onto silicon substrates using both hot-filament CVD and microwave plasma CVD systems. The key feature of TMCVD is that it modulates methane (CH4) flow during diamond CVD, whereas in conventional CVD the CH4 flow is kept constant throughout the deposition process. Films grown using TMCVD were smoother, harder, and displayed better quality than similar films grown using constant CH4 flow during CVD. The advantage of using TMCVD is that it promotes secondary nucleation to occur on existing diamond crystals. Pulsing CH4, consecutively, at high and low concentrations allows the depositing film to maintain its quality in terms of diamond-carbon phase. Films grown under constant CH4 flow during diamond CVD displayed a columnar growth mode, whereas with the time modulated films the growth mode was different. The mechanism of film growth during TMCVD is presented in this paper. The growth rate of films obtained using the hot filament CVD system with constant CH4 flow was higher than the growth rate of time modulated films. However, using the microwave-plasma CVD system, the effect was the contrary and the time-modulated films were grown at a higher rate. The growth rate results are discussed in terms of substrate temperature changes during TMCVD.

YBa2Cu3O7 Thin Films on Polycrystalline Diamond Films with Buffer Layers

1992 ◽  
Vol 275 ◽  
Author(s):  
G. Cui ◽  
C. P. Beetz ◽  
B. A. Lincoln ◽  
P. S. Kirlin
Keyword(s):  
Thin Films ◽  
Diamond Films ◽  
Rf Sputtering ◽  
Polycrystalline Diamond ◽  
Fast Response ◽  
Buffer Layers ◽  
Multichip Modules ◽  
Ir Detectors ◽  
Ybco Films ◽  
First Time

ABSTRACTThe deposition of in-situ YBa2CU3O7-δ Superconducting films on polycrystalline diamond thin films has been demonstrated for the first time. Three different composite buffer layer systems have been explored for this purpose: (1) Diamond/Zr/YSZ/YBCO, (2) Diamond/Si3N4/YSZ/YBCO, and (3) Diamond/SiO2/YSZ/YBCO. The Zr was deposited by dc sputtering on the diamond films at 450 to 820 °C. The YSZ was deposited by reactive on-axis rf sputtering at 680 to 750 °C. The Si3N4 and SiO2 were also deposited by on-axis rf sputtering at 400 to 700 °C. YBCO films were grown on the buffer layers by off-axis rf sputtering at substrate temperatures between 690 °C and 750 °C. In all cases, the as-deposited YBCO films were superconducting above 77 K. This demonstration enables the fabrication of low heat capacity, fast response time bolometric IR detectors and paves the way for the use of HTSC on diamond for interconnect layers in multichip modules.

Deposition of large area uniform diamond films by microwave plasma CVD

Vacuum ◽  
2018 ◽  
Vol 147 ◽  
pp. 134-142 ◽  
Author(s):  
J. Weng ◽  
F. Liu ◽  
L.W. Xiong ◽  
J.H. Wang ◽  
Q. Sun
Keyword(s):  
Microwave Plasma ◽  
Diamond Films ◽  
Plasma Cvd ◽  
Large Area ◽  
Microwave Plasma Cvd

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.

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