Elastic modulus of single-crystal GaN nanowires

2006 ◽  
Vol 21 (11) ◽  
pp. 2882-2887 ◽  
Author(s):  
Hai Ni ◽  
Xiaodong Li ◽  
Guosheng Cheng ◽  
Robert Klie

The deformation behavior of single-crystal GaN nanowires was studied by directly performing three-point bending tests on each individual nanowire in an atomic force microscope. The elastic modulus calculated from the load–displacement response of the nanowires was 43.9 ± 2.2 GPa. Single-crystal GaN nanowires investigated in this study were synthesized by chemical vapor deposition techniques based on the vapor–liquid–solid growth mechanism and had a diameter range from 60 to 110 nm. Crystalline GaN nanowires did not show obvious plastic deformation in bending and usually failed in a brittle manner.

2017 ◽  
Vol 7 (6) ◽  
pp. 1995 ◽  
Author(s):  
Umar Saleem ◽  
Muhammad Danang Birowosuto ◽  
Noelle Gogneau ◽  
Philippe Coquet ◽  
Maria Tchernycheva ◽  
...  

Author(s):  
N. J. Tighe ◽  
J. Sun ◽  
R.-M. Hu

Particles of BN,and C are added in amounts of 1 to 40% to SiC and Si3N4 ceramics in order to improve their mechanical properties. The ceramics are then processed by sintering, hot-pressing and chemical vapor deposition techniques to produce dense products. Crack deflection at the particles can increase toughness. However the high temperature strength and toughness are determined byphase interactions in the environmental conditions used for testing. Examination of the ceramics by transmission electron microscopy has shown that the carbon and boron nitride particles have a fibrous texture. In the sintered aSiC ceramic the carbon appears as graphite fiber bundles in the triple junctions and as compact graphite particles within some grains. Examples of these inclusions are shown in Fig. 1A and B.


2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Chaocheng Wang ◽  
Wei Chen ◽  
Cheng Han ◽  
Guang Wang ◽  
Binbing Tang ◽  
...  

1995 ◽  
Vol 403 ◽  
Author(s):  
G. Bai ◽  
S. Wittenbrock ◽  
V. Ochoa ◽  
R. Villasol ◽  
C. Chiang ◽  
...  

AbstractCu has two advantages over Al for sub-quarter micron interconnect application: (1) higher conductivity and (2) improved electromigration reliability. However, Cu diffuses quickly in SiO2and Si, and must be encapsulated. Polycrystalline films of Physical Vapor Deposition (PVD) Ta, W, Mo, TiN, and Metal-Organo Chemical Vapor Deposition (MOCVD) TiN and Ti-Si-N have been evaluated as Cu diffusion barriers using electrically biased-thermal-stressing tests. Barrier effectiveness of these thin films were correlated with their physical properties from Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM), Secondary Electron Microscopy (SEM), and Auger Electron Spectroscopy (AES) analysis. The barrier failure is dominated by “micro-defects” in the barrier film that serve as easy pathways for Cu diffusion. An ideal barrier system should be free of such micro-defects (e.g., amorphous Ti-Si-N and annealed Ta). The median-time-to-failure (MTTF) of a Ta barrier (30 nm) has been measured at different bias electrical fields and stressing temperatures, and the extrapolated MTTF of such a barrier is > 100 year at an operating condition of 200C and 0.1 MV/cm.


2003 ◽  
Vol 15 (9) ◽  
pp. 1763-1765 ◽  
Author(s):  
Naoyuki Takahashi ◽  
Yusuke Nakatani ◽  
Takuma Yatomi ◽  
Takato Nakamura

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