Misfit Dislocation Sources at Surface Ripple Troughs in Continuous Heteroepitaxial Layers

Cullis, A. G.; Pidduck, A. J.; Emeny, M. T.

doi:10.1103/physrevlett.75.2368

Cited by 98 publications

(38 citation statements)

References 26 publications

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“…It manifests itself in a diverse range of phenomena, such as formation of gradual surface undulations (cross-hatch patterns) arising from the surface mass transport driven by the strain fields of the misfit dislocations [2-4], elastic [5] and plastic [6] displacements of the surface by misfit dislocations, and dislocation nucleation at surfaceripple structures in continuous heteroepitaxial layers [7][8][9][10]. Alignment of the surface-ripple domains along dislocation lines was observed in Si 12x Ge x ͞Si heteroepitaxial systems and attributed to ripple-dislocation interactions mediated by strain [7,10].…”

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confidence: 99%

Nanoscale Structuring by Misfit Dislocations inSi1−xGex/SiEpita

et al. 1997

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Nanoscale Structuring by Misfit Dislocations inSi1−xGex/SiEpita

et al. 1997

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“…Such processes have been considered in a number of studies using continuum models. [15][16][17] However, it has been pointed out that surface steps and surface roughness that are not considered in the continuum models could play an important role for dislocation nucleation. 18 -20 Thus, atomistic studies are important for a detailed understanding and determination of the possible mechanisms for defect nucleation in epitaxial films.…”

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Energetics and atomic mechanisms of dislocation nucleation in strained epitaxial layers

et al. 2003

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We numerically study the energetics and atomic mechanisms of misfit dislocation nucleation and stress relaxation in a two-dimensional atomistic model of strained epitaxial layers on a substrate with lattice misfit. Relaxation processes from coherent to incoherent states for different transition paths are studied using interatomic potentials of Lennard-Jones type and a systematic saddle-point and transition-path search method. The method is based on a combination of a repulsive potential minimization and the nudged elastic band method. For a final state with a single misfit dislocation, the minimum-energy path and the corresponding activation barrier are obtained for different misfits and interatomic potentials. We find that the energy barrier decreases strongly with misfit. In contrast to continuous elastic theory, a strong tensile-compressive asymmetry is observed. This asymmetry can be understood as a manifestation of the asymmetry between repulsive and attractive branches of the pair potential, and it is found to depend sensitively on the form of the potential.

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“…Such processes have been considered in a number of studies within continuum models. [8][9][10] It has been pointed out that surface steps and surface roughness that are not included in the continuum model could play an important role for dislocation nucleation. [11][12][13][14] Thus, atomistic study is important for a detailed understanding and direct determination of the mechanisms for defect nucleation in epitaxial films.…”

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confidence: 99%

Minimum energy paths for dislocation nucleation in strained epitaxial layers

et al. 2002

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We study numerically the minimum energy path and energy barriers for dislocation nucleation in a twodimensional atomistic model of strained epitaxial layers on a substrate with lattice misfit. Stress relaxation processes from coherent to incoherent states for different transition paths are determined using saddle point search based on a combination of repulsive potential minimization and the Nudged Elastic Band method. The minimum energy barrier leading to a final state with a single misfit dislocation nucleation is determined. A strong tensile-compressive asymmetry is observed. This asymmetry can be understood in terms of the qualitatively different transition paths for the tensile and compressive strains.

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Misfit Dislocation Sources at Surface Ripple Troughs in Continuous Heteroepitaxial Layers

Cited by 98 publications

References 26 publications

Nanoscale Structuring by Misfit Dislocations inSi1−xGex/SiEpita

Nanoscale Structuring by Misfit Dislocations inSi1−xGex/SiEpita

Energetics and atomic mechanisms of dislocation nucleation in strained epitaxial layers

Minimum energy paths for dislocation nucleation in strained epitaxial layers

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