Effect of Mechanical Stress on Polycrystalline Diamond Schottky Diode I-V Characteristics

1992 ◽  
Vol 270 ◽  
Author(s):  
G. Zhao ◽  
E. M. Charlson ◽  
E. J. Charlson ◽  
T. Stacy ◽  
J. Meese ◽  
...  

ABSTRACTSchottky diodes to be used for mechanical stress effect studies were fabricated using aluminum contacts to polycrystalline diamond thin films grown by a hot-filament assisted chemical vapor deposition process. Compressive stress was found to have a large effect on the forward biased current-voltage characteristics of the diode. At selected values of constant forward biased current, a linear relationship between voltage and stress, for stress less than 10 N was observed. The stress sensitivity of the diode was as high as 0.74 V/N at 1 mA forward bias. This study shows that polycrystalline diamond Schottky diodes are stress sensitive devices and have potential as mechanical sensors.

2020 ◽  
Vol 10 (17) ◽  
pp. 6090
Author(s):  
Daidong Guo ◽  
Ningning Cai ◽  
Guoping Wu ◽  
Fangmin Xie ◽  
Shouhong Tan ◽  
...  

Polycrystalline diamond (PCD)-coated mechanical seal rings were prepared by hot filament chemical vapor deposition (HFCVD) on graphite-loaded silicon carbide (GSiC) substrates. From the initial deposition process, the diamond first nucleated and then grew into a dense coating with grain size of 4 μm and thickness of 12.3 μm. The well-grown PCD coating, as confirmed by Raman spectroscopy and X-ray diffractometry, significantly improves the pressure–velocity limit of the mechanical seal applied in harsh operating conditions, no matter whether for a hard-to-soft mating combination or a hard-to-hard mating combination. Comparing GSiC against sintered silicon carbide (SSiC) combination (GSiC/SSiC), GSiC against graphite combination (GSiC/graphite) and PCD against graphite combination (PCD/graphite), PCD against SSiC combination (PCD/SSiC) shows the highest pressure velocity (PV) limit of 42.31 MPa·m/s with 4 kN loading at 4500 rpm rotation speed. An extremely low and stable friction coefficient and super mechanical properties under harsh conditions can be approved as the source of the high PV limit of PCD coating. A mechanical seal with PCD coating can be used for more demanding applications.


1992 ◽  
Vol 61 (9) ◽  
pp. 1119-1121 ◽  
Author(s):  
G. Zhao ◽  
T. Stacy ◽  
E. J. Charlson ◽  
E. M. Charlson ◽  
C. H. Chao ◽  
...  

1996 ◽  
Vol 11 (7) ◽  
pp. 1765-1775 ◽  
Author(s):  
James M. Olson ◽  
Michael J. Dawes

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.


1996 ◽  
Vol 423 ◽  
Author(s):  
S. Mirzakuchaki ◽  
H. Golestanian ◽  
E. J. Charlson ◽  
T. Stacy

AbstractAlthough many researchers have studied boron-doped diamond thin films in the past several years, there have been few reports on the effects of doping CVD-grown diamond films with phosphorous. For this work, polycrystalline diamond thin films were grown by hot filament chemical vapor deposition (HFCVD) on p-type silicon substrates. Phosphorous was introduced into the reaction chamber as an in situ dopant during the growth. The quality and orientation of the diamond thin films were monitored by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Current-voltage (I-V) data as a function of temperature for golddiamond film-silicon-aluminum structures were measured. The activation energy of the phosphorous dopants was calculated to be approximately 0.29 eV.


1994 ◽  
Vol 3 (4-6) ◽  
pp. 618-622 ◽  
Author(s):  
Takashi Sugino ◽  
Kiyoshi Karasutani ◽  
Fumihiro Mano ◽  
Hiroya Kataoka ◽  
Junji Shirafuji ◽  
...  

2013 ◽  
Vol 845 ◽  
pp. 36-40
Author(s):  
Tze Mi Yong ◽  
Esah Hamzah

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.


1992 ◽  
Vol 7 (10) ◽  
pp. 2785-2790 ◽  
Author(s):  
V.P. Godbole ◽  
J. Narayan

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.


2006 ◽  
Vol 527-529 ◽  
pp. 911-914 ◽  
Author(s):  
D.J. Ewing ◽  
Qamar-ul Wahab ◽  
Sergey P. Tumakha ◽  
Leonard J. Brillson ◽  
X.Y. Ma ◽  
...  

In this study, we performed a statistical analysis of 500 Ni Schottky diodes distributed across a 2-inch, n-type 4H-SiC wafer with an epilayer grown by chemical vapor deposition. A majority of the diodes displayed ideal thermionic emission when under forward bias, whereas some diodes showed ‘double-barrier’ characteristics with a ‘knee’ in the low-voltage log I vs. V plot. X-ray topography (XRT) and polarized light microscopy (PLM) revealed no correlations between screw dislocations and micropipes and the presence of double-barrier diodes. Depth resolved cathodoluminescence (DRCLS) indicated that certain deep-level states are associated with the observed electrical variations.


1994 ◽  
Vol 339 ◽  
Author(s):  
G. Zhao ◽  
T. Stacy ◽  
E. M. Charlson ◽  
E. J. Charlson ◽  
M. Hajsaid ◽  
...  

ABSTRACTWe are reporting the first quantitative photoresponse characteristics of boron doped hot-filament CVD (HFCVD) diamond based Schottky diodes using semi-transparent aluminum contacts in the spectral range of 300–1050 nm. Quantum efficiencies, obtained without correction for surface reflection in the visible and near UV region, were between 5 % and 10% when the diodes were unbiased. Effect of reverse bias on the photoresponse was investigated at selected photon energies. Reverse biased diodes exhibit increasing photoresponse and ultimately saturation. Quantum efficiency as high as 30% was also obtained at 500 nm, when a reverse bias of over I volt was applied. The photoresponse mechanism of CVD diamond Schottky diodes is also discussed. A Schottky barrier height of 1.15 ± 0.02 eV for Al-HFCVD diamond contacts was determined using the d.c. photoelectric method.


1997 ◽  
Vol 483 ◽  
Author(s):  
J. L. Davidson ◽  
W. P. Kang ◽  
Y. Gurbuz ◽  
D. V. Kerns ◽  
L. Davis ◽  
...  

AbstractDiamond based power device structures such as resistor, capacitor, Schottky diode, p-n diode, thyristor, and field emitters are being investigated. Diamond resistors similar to standard thick film components in form and dimension were fabricated of polycrystalline diamond film. Using PECVD (plasma-enhanced chemical vapor deposition) processing to achieve diamond dielectric layers, high power, high energy density capacitors have been built. Despite grain boundaries and defects of polycrystalline diamond film, electronic devices such as field-effecttransistors and Schottky diodes have been developed. We have fabricated micro-patterned microtip arrays with this versatile new diamond technology as electron emitters. This paper will review diamond technology and results of this work.


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