Surface Instability and Dislocation Nucleation in Strained Epitaxial Layers

Mechanisms of Dislocation Nucleation in Strained Epitaxial Layers

Using molecular static simulations we have studied possible mechanisms of stress relaxation with misfit dislocation nucleation in strained heteroepitaxial layers. Two-dimensional models of atomic systems with Lennard-Jones type potential were considered. Combination of total energy minimization with spherical repulsion and nudged elastic band calculation allowed us to study possible transitions...

Equilibrium shape and dislocation nucleation in strained epitaxial nanoislands

Mechanics of coherent and dislocated island morphologies in strained epitaxial material systems

A combined analytical and computational model is developed to study the mechanics of strained epitaxial island growth in typical semiconductor systems. Under certain growth conditions in systems with a film/substrate lattice mismatch, deposited material is known to aggregate into islandlike shapes with geometries having arc shaped cross-sections. A two-dimensional model assuming linear elastic ...

Nucleation mechanisms and the elimination of misfit dislocations at mismatched interfaces

To investigate the effect of growth area on interface dislocation density in strained-layer epitaxy, we have fabricated 2-.um-high mesas of varying lateral dimensions and geometry in (001) GaAs substrates with dislocation densities of 1.5 X 10\ 10, and 10 cm-2 • 3500-, 7000-, and 8250-A-thick Ino (J5 Gao 95 As layers, corresponding to 5, to, and 11 times the experimental critical layer thicknes...

Epitaxial nucleation of a crystal on a crystalline surface

We consider the nucleation of a crystal phase, on a crystalline surface of a different substance. Sixty years ago, Turnbull and Vonnegut predicted that a crystalline surface is best at inducing nucleation of another crystal when there is a perfect epitaxial match between the two bulk lattices. We use computer simulation to show that this is not quite right. In fact, the crystal lattice of a fin...