Anisotropic misfit dislocation nucleation in two-dimensional grown InAs/GaAs(001) heterostructures

1998 ◽  
Vol 73 (8) ◽  
pp. 1074-1076 ◽  
Author(s):  
Achim Trampert ◽  
Klaus H. Ploog ◽  
Eric Tournié
1990 ◽  
Vol 198 ◽  
Author(s):  
D.C. Houghton ◽  
N.L. Rowell

ABSTRACTThe thermal constraints for device processing imposed by strain relaxation have been determined for a wide range of Si-Ge strained heterostructures. Misfit dislocation densities and glide velocities in uncapped Sil-xGex alloy layers, Sil-xGex single and multiple quantum wells have been measured using defect etching and TEM for a range of anneal temperatures (450°C-1000°C) and anneal times (5s-2000s). The decay of an intense photoluminescence peak (∼ 10% internal quantum efficiency ) from buried Si1-xGex strained layers has been correlated with the generation of misfit dislocations in adjacent Sil-xGex /Si interfaces. The misfit dislocation nucleation rate and glide velocity for all geometries and alloy compositions (0<x<0.25) were found to be thermally activated processes with activation energies of (2.5±0.2)eV and (2.3-0.65x)eV, respectively. The time-temperature regime available for thermal processing is mapped out as a function of dislocation density using a new kinetic model.


2000 ◽  
Vol 634 ◽  
Author(s):  
A. Kuronen ◽  
K. Kaski ◽  
L. F. Perondi ◽  
J. Rintala

ABSTRACTMechanisms responsible for the formation of a misfit dislocation in a lattice-mismatched system have been studied using Molecular Dynamics simulations of a two-dimensional Lennard-Jones system. Results show clearly how the strain due to the lattice-mismatched interface acts as a driving force for migration of dislocations in the substrate and the overlayer and nucleation of dislocations in the overlayer edges. Moreover, we observe dislocation reactions in which the gliding planes of dislocations change such that they can migrate to the interface.


1996 ◽  
Vol 436 ◽  
Author(s):  
R. V. Kukta ◽  
L. B. Freund

AbstractStrained islands grown coherently on a relatively thick substrate with similar elastic properties are considered within the framework of continuum mechanics. The condition of uniform surface chemical potential is imposed to calculate two-dimensional equilibrium island shapes. The stress distribution in the equilibrium islands is shown to be highly nonhomogeneous. The effects of introducing a single misfit dislocation at the island-substrate interface are considered. It is found that there is critical island volume above which a dislocation decreases the total free energy of the system. The dislocation alters the stress distribution in the island, causing the island to relax via mass transport to an equilibrium shape with a lower height-to-width aspect ratio and a smaller surface chemical potential than the island prior to the introduction of the dislocation.


2001 ◽  
Vol 148 (7) ◽  
pp. G379 ◽  
Author(s):  
Petra Feichtinger ◽  
Mark S. Goorsky ◽  
Dwain Oster ◽  
Tom D’Silva ◽  
Jim Moreland

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