Effect of Elastic Mismatch and Anisotropy on Cracking of Brittle Films on Elastic Substrates

2011 ◽  
Vol 465 ◽  
pp. 235-238
Author(s):  
Michal Kotoul ◽  
Tomas Vyslouzil
Keyword(s):  
Weight Function ◽  
Epitaxial Layer ◽  
Elastic Anisotropy ◽  
Minimum Energy ◽  
Inp Substrate ◽  
Elastic Substrates ◽  
Elastic Mismatch

The paper analyzes the depth and spacing of cracks in a tensile strained In0.25Ga0.75As epitaxial layer on a InP substrate using the minimum energy theorem. The elastic anisotropy of both the layer and the substrate is considered. The concept of weight function obtained numerically by means of detailed FEM is employed.

1.55 µm InGaAsP/InP laser buried in a high-resistivity epitaxial layer on a semi-insulating InP substrate

1994 ◽  
Vol 30 (18) ◽  
pp. 1481-1482 ◽  
Author(s):  
Y. Sakai ◽  
M. Fukuda ◽  
S. Matsumoto ◽  
Y. Itaya ◽  
M. Yamamoto
Keyword(s):  
Epitaxial Layer ◽  
High Resistivity ◽  
Inp Substrate

scholarly journals Scanning X-ray nanodiffraction from ferroelectric domains in strained K0.75Na0.25NbO3 epitaxial films grown on (110) TbScO3

2017 ◽  
Vol 50 (2) ◽  
pp. 519-524 ◽  
Author(s):  
Martin Schmidbauer ◽  
Michael Hanke ◽  
Albert Kwasniewski ◽  
Dorothee Braun ◽  
Leonard von Helden ◽  
...  
Keyword(s):  
Epitaxial Layer ◽  
Elastic Anisotropy ◽  
Elastic Strain Energy ◽  
Epitaxial Films ◽  
Linear Elasticity Theory ◽  
X Ray ◽  
Probe Size ◽  
Ferroelectric Domains ◽  
Elastic Strain Energy Density ◽  
Domain Variant

Scanning X-ray nanodiffraction on a highly periodic ferroelectric domain pattern of a strained K0.75Na0.25NbO3 epitaxial layer has been performed by using a focused X-ray beam of about 100 nm probe size. A 90°-rotated domain variant which is aligned along [1{\overline 1}2]TSO has been found in addition to the predominant domain variant where the domains are aligned along the [{\overline 1}12]TSO direction of the underlying (110) TbScO3 (TSO) orthorhombic substrate. Owing to the larger elastic strain energy density, the 90°-rotated domains appear with significantly reduced probability. Furthermore, the 90°-rotated variant shows a larger vertical lattice spacing than the 0°-rotated domain variant. Calculations based on linear elasticity theory substantiate that this difference is caused by the elastic anisotropy of the K0.75Na0.25NbO3 epitaxial layer.

Three Dimensional Surface Waviness of an Epitaxial Layer Due to Surface Diffusion Induced by Interface Misfit Dislocations

1994 ◽  
Vol 356 ◽  
Author(s):  
F. Jonsdottir
Keyword(s):  
Surface Diffusion ◽  
Epitaxial Layer ◽  
Thermodynamic Equilibrium ◽  
Three Dimensional ◽  
Misfit Dislocations ◽  
Surface Waviness ◽  
Mismatch Strain ◽  
Equilibrium Surface ◽  
Elastic Mismatch ◽  
Dimensional Surface

AbstractIt has been observed that, for some strained epitaxial layer systems, the surface of the layer develops roughness or waviness which correlates spatially with the positions of underlying interface misfit dislocations which partially relax the elastic mismatch strain. A model based on redistribution of mass by surface diffusion is analyzed to estimate the waviness of the three dimensional thermodynamic equilibrium surface due to intersecting arrays of interface misfit dislocations.

scholarly journals Influence of Interfacial Delamination on Channel Cracking of Brittle Thin Films

2007 ◽  
Vol 990 ◽  
Author(s):  
Yaoyu Pang ◽  
Rui Huang
Keyword(s):  
Thin Films ◽  
Driving Force ◽  
Fracture Resistance ◽  
Buffer Layers ◽  
Constraint Effect ◽  
Interfacial Delamination ◽  
Elastic Substrates ◽  
Elastic Mismatch ◽  
Reliability Issue ◽  
Low K

ABSTRACTChanneling cracks in low-k dielectrics have been observed to be a key reliability issue for advanced interconnects. The constraint effect of surrounding materials including stacked buffer layers has been studied. This paper analyzes the effect of interfacial delamination on the fracture condition of brittle thin films on elastic substrates. It is found that stable delamination along with the growth of a channel crack is possible only for a specific range of elastic mismatch and interface toughness. An effective energy release rate is defined to account for the influence of interfacial delamination on both the driving force and the fracture resistance, which can be significantly higher than the case assuming no delamination.

Cristal-growth dynamics of n-doped gaAs

1992 ◽  
Vol 50 (2) ◽  
pp. 1544-1545
Author(s):  
Pham V. Huong ◽  
Stéphanie Bouchet ◽  
Jean-Claude Launay
Keyword(s):  
Crystal Growth ◽  
Spatial Resolution ◽  
Epitaxial Layer ◽  
Outer Surface ◽  
Gaas Substrate ◽  
Structural Modification ◽  
Growth Dynamics ◽  
Argon Laser ◽  
High Anisotropy ◽  
Crystal Gaas

Microstructure of epitaxial layers of doped GaAs and its crystal growth dynamics on single crystal GaAs substrate were studied by Raman microspectroscopy with a Dilor OMARS instrument equipped with a 1024 photodiode multichannel detector and a ion-argon laser Spectra-Physics emitting at 514.5 nm.The spatial resolution of this technique, less than 1 μm2, allows the recording of Raman spectra at several spots in function of thickness, from the substrate to the outer deposit, including areas around the interface (Fig.l).The high anisotropy of the LO and TO Raman bands is indicative of the orientation of the epitaxial layer as well as of the structural modification in the deposit and in the substrate at the interface.With Sn doped, the epitaxial layer also presents plasmon in Raman scattering. This fact is already very well known, but we additionally observed that its frequency increases with the thickness of the deposit. For a sample with electron density 1020 cm-3, the plasmon L+ appears at 930 and 790 cm-1 near the outer surface.

On the Form of Decision Weight Function

2002 ◽  
Author(s):  
Shyhnan Liou ◽  
Chung-Ping Cheng
Keyword(s):  
Weight Function
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