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

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.

1990 ◽  
Vol 5 (11) ◽  
pp. 2483-2489 ◽  
Author(s):  
K. Tankala ◽  
T. DebRoy ◽  
M. Alam

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.


CrystEngComm ◽  
2020 ◽  
Vol 22 (12) ◽  
pp. 2138-2146 ◽  
Author(s):  
G. Shu ◽  
V. G. Ralchenko ◽  
A. P. Bolshakov ◽  
E. V. Zavedeev ◽  
A. A. Khomich ◽  
...  

Homoepitaxial diamond growth may proceed with stops and resumptions to produce thick crystals. We found the resumption procedure to take place in a complex way, via a disturbance of step growth features, followed by the recovery after a certain time.


2018 ◽  
Vol 44 (15) ◽  
pp. 17845-17851 ◽  
Author(s):  
Kang An ◽  
Liangxian Chen ◽  
Xiongbo Yan ◽  
Xin Jia ◽  
Jinlong Liu ◽  
...  

1993 ◽  
Vol 317 ◽  
Author(s):  
M.M. Waitew ◽  
S. Ismat Shah

ABSTRACTDiamond films were deposited in a microwave plasma chemical vapor deposition (MPCVD) system on Ta substrates using a mixture of hydrogen and methane gases. The films were grown for varying lengths of time to provide samples with no diamond growth to a continuous diamond film. These films were analyzed using X-ray photoelectron spectroscopy (XPS) in order to understand the time dependent interactions between the substrate and the incoming carbon flux. Photoelectron peaks in the Ta 4f, C Is and Ols regions have been analyzed. In the initial stages of growth, a layer of carbide forms on the substrate. As the substrate becomes supersaturated with carbon, graphite starts to form on the surface. A diamond peak begins to appear after about 30 Minutes of deposition.


1997 ◽  
Vol 12 (10) ◽  
pp. 2686-2698 ◽  
Author(s):  
L. Fayette ◽  
B. Marcus ◽  
M. Mermoux ◽  
N. Rosman ◽  
L. Abello ◽  
...  

A sequential analysis of the growth of diamond films on silicon substrates in a microwave plasma assisted chemical vapor deposition (CVD) reactor has been performed by Raman spectroscopy. The plasma was switched off during measurements, but the substrate heating was maintained to minimize thermoelastic stresses. The detectivity of the present experimental setup has been estimated to be about a few tens of μmg/cm2. From such a technique, one expects to analyze different aspects of diamond growth on a non-diamond substrate. The evolution of the signals arising from the substrate shows that the scratching treatment used to increase the nucleation density induces an amorphization of the silicon surface. This surface is annealed during the first step of deposition. The evolution of the line shape of the spectra indicates that the non-diamond phases are mainly located in the grain boundaries. The variation of the integrated intensity of the Raman signals has been interpreted using a simple absorption model. A special emphasis was given to the evolution of internal stresses during deposition. It was verified that compressive stresses were generated when coalescence of crystals took place.


1994 ◽  
Vol 9 (8) ◽  
pp. 2154-2163 ◽  
Author(s):  
K.J. Grannen ◽  
R.P.H. Chang

Microwave plasma-enhanced chemical vapor deposition of diamond films on silicon carbide and tungsten carbide (with 6% cobalt) surfaces using fluorocarbon gases has been demonstrated. No diamond powder pretreatment is necessary to grow these films with a (100) faceted surface morphology. The diamond films are characterized by scanning electron microscopy and Raman spectroscopy. The proposed nucleation and growth mechanism involves etching of the noncarbon component of the carbide by atomic fluorine to expose surface carbon atoms and diamond nucleation and growth on these exposed carbon atoms. Hydrogen is necessary in the growth process to limit the rapid etching of the carbide substrates by corrosive fluorine atoms.


1995 ◽  
Vol 416 ◽  
Author(s):  
S. L. Girshick ◽  
J. W. Lindsay

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.


2010 ◽  
Vol 663-665 ◽  
pp. 625-628
Author(s):  
Fu Yuan Xia ◽  
Lin Jun Wang ◽  
Jian Huang ◽  
Ke Tang ◽  
Ji Jun Zhang ◽  
...  

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.


Sign in / Sign up

Export Citation Format

Share Document