High velocity pseudo-SAWs on CVD diamond substrate

2002 ◽  
Author(s):  
N. Chong ◽  
H.L.W. Chan ◽  
K.P. Kwok ◽  
C.L. Choy
Keyword(s):  
High Velocity ◽  
Cvd Diamond ◽  
Diamond Substrate

Analysis of propagation characteristics of Rayleigh surface acoustic waves on Yb0.33Al0.67N piezoelectric films/high-velocity substrates

2022 ◽  
Author(s):  
Masashi Suzuki ◽  
Shoji Kakio
Keyword(s):  
High Velocity ◽  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Film Surface ◽  
Layered Structures ◽  
Coupling Factor ◽  
Propagation Characteristics ◽  
Effective Coupling ◽  
Diamond Substrate ◽  
Coupling Factors

Abstract Piezoelectricity of YbAlN films has recently been shown to be almost as high as that of ScAlN films. YbAlN film surface acoustic wave (SAW) resonators are expected to have a high coupling factor. We theoretically investigated the propagation characteristics of first-mode Rayleigh SAWs (RSAWs) on Yb0.33Al0.67N film/high-velocity Si, sapphire, AlN, SiC, BN, and diamond substrates. The first-mode RSAWs on the YbAlN layered structures had high coupling factors, higher than those on ScAlN layered structures. An enhancement of the effective coupling factor of the first mode RSAWs was observed in polarity inverted YbAlN film/BN or diamond substrate structures.

Device Characteristics Dependence on Diamond SDBs Area

2009 ◽  
Vol 615-617 ◽  
pp. 1003-1006 ◽  
Author(s):  
Hitoshi Umezawa ◽  
Kazuhiro Ikeda ◽  
Ramanujam Kumaresan ◽  
Natsuo Tatsumi ◽  
Shinichi Shikata
Keyword(s):  
Leakage Current ◽  
Doping Concentration ◽  
Reverse Bias ◽  
Cvd Diamond ◽  
Density Of Dislocations ◽  
Parasitic Resistance ◽  
Diamond Substrate ◽  
Single Crystal Diamond ◽  
Device Applications ◽  
Device Size

Device size scaling of pseudo-vertical diamond Schottky barrier diodes (SBDs) has been characterized for high-power device applications based on the control of doping concentration and thickness of the p- CVD diamond layer. Decreasing parasitic resistance on the p+ layer utilizing lithography and etching makes possible to get a constant specific on-resistance of less than 20 mOhm-cm2 with increasing device size up to 200 µm. However, the leakage current under low reverse bias conditions is increased markedly. Due to the increase in the leakage current, the reverse operation limit is decreased from 2.4 to 1.3 MV/cm when the device size is increased from 30 to 150 µm. If defects induce an increase in leakage current under the reverse conditions, the density of the defects can be estimated to be 104–105/cm2. This value is 5–10 times larger than the density of dislocations in single crystal diamond substrate.

scholarly journals CVD diamond/substrate interface FIB preparation of cutting tools

2009 ◽  
Vol 15 (S3) ◽  
pp. 57-58 ◽  
Author(s):  
S. B. Peripolli ◽  
F. A. Almeida ◽  
L. S. Gomes ◽  
F. J. Oliveira ◽  
R. F. Silva ◽  
...  
Keyword(s):  
Cutting Tools ◽  
Interfacial Strength ◽  
Cvd Diamond ◽  
Substrate Material ◽  
Detection Sensitivity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hard Materials ◽  
Diamond Substrate ◽  
Graded Interlayer

AbstractCVD diamond coated cutting tools are used for machining of abrasive and hard materials such as Al-Si alloys and tungsten carbide. The knowledge of the mechanisms governing the diamond/substrate interfacial strength is crucial in cutting tools design. The most adequate substrate material for maximizing the adhesion of diamond films is the silicon nitride (Si3N4) ceramic that possesses a thermal expansion coefficient similar to that of diamond. Buchkremer-Hermanns and co-workers consider the formation of a SiC interlayer between diamond and Si3N4, which may favour chemical bonding to diamond, although they could not detect it by glazing incidence X-Ray diffraction. They believed that insufficient detection sensitivity for very thin films, texture effects or presence of amorphous layers are possible reasons. In the case of TiN substrates, a graded interlayer of amorphous TiCN of only 8 Å was suggested by Contreras, as observed by HRTEM images and EDS measurements. Due to the difficulty in the detection of such layers, which can be in the order of a few angstrons, a definite evidence of their nature is yet to be demonstrated.

Selective Seeding and Growth of Nanocrystalline CVD Diamond on Non-Diamond Substrates

2011 ◽  
Vol 1339 ◽  
Author(s):  
P. Pobedinskas ◽  
S.D. Janssens ◽  
J. Hernando ◽  
P. Wagner ◽  
M. Nesládek ◽  
...  
Keyword(s):  
Aluminum Nitride ◽  
Hydrogen Plasma ◽  
Cvd Diamond ◽  
Nanocrystalline Diamond ◽  
Surface Roughening ◽  
Nucleation Density ◽  
Surface Pretreatment ◽  
Acidic Pretreatment ◽  
Diamond Substrate ◽  
Key Factor

ABSTRACTA study is presented on nanocrystalline diamond (NCD) growth on different substrates, including silicon with and without different metallic interlayers, on aluminum nitride (AlN), and on a Si/AlN-based cantilever. It is shown that non-diamond substrate treatment prior to NCD growth is important for achieving high nucleation densities. AFM measurements reveal that an additional Si surface pretreatment with hydrogen plasma increases the nucleation density by a factor of four. A similar effect was indirectly demonstrated with acidic pretreatment of AlN. In both cases it is believed that the surface roughening is the key factor for explaining this phenomenon.

Selective Metallization of CVD Diamond Films

1992 ◽  
Vol 260 ◽  
Author(s):  
J. M. Calvert ◽  
P. E. Pehrsson ◽  
C. S. Dulcey ◽  
M. C. Peckerar
Keyword(s):  
Ultrathin Films ◽  
Diamond Films ◽  
Peel Test ◽  
Cvd Diamond ◽  
Diamond Surface ◽  
Processing Conditions ◽  
Diamond Substrate ◽  
Low Temperature Processing ◽  
Modified Surfaces ◽  
Oxidized Diamond

ABSTRACTA process has been developed for the deposition of patterned adherent metal on diamond substrates using low temperature processing conditions. CVD diamond films on Si wafers were oxidized with an RFO2 plasma and subsequently functionalized by attachment of self-assembled ultrathin films (UTFs) to the oxidized diamond surface. The UTFs were exposed to patterned deep UV radiation, and selectively metallized by electroless (EL) deposition. EL Ni and Co patterns, with feature sizes to 20 μm linewidth have been produced. Oxidized and UTF-modified surfaces were characterized by surface spectroscopie and wettability techniques. The EL metal deposits on the diamond substrate passed the Scotch tape adhesion peel test.

Sign in / Sign up

Export Citation Format

Share Document