Design rules for dislocation filters

Journal Article · Thu Aug 14 04:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4892162· OSTI ID:22314593

Ward, T.; Sánchez, A. M.; Tang, M.; Wu, J.; Liu, H. ^[1]; Dunstan, D. J. ^[2]

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1. Department of Electronic and Electrical Engineering, University College London, Torrington Place, London WC1E 7JE (United Kingdom)
2. School of Physics and Astronomy, Queen Mary University of London, London E1 4NS (United Kingdom)

The efficacy of strained layer threading dislocation filter structures in single crystal epitaxial layers is evaluated using numerical modeling for (001) face-centred cubic materials, such as GaAs or Si{sub 1−x}Ge{sub x}, and (0001) hexagonal materials such as GaN. We find that threading dislocation densities decay exponentially as a function of the strain relieved, irrespective of the fraction of threading dislocations that are mobile. Reactions between threading dislocations tend to produce a population that is a balanced mixture of mobile and sessile in (001) cubic materials. In contrast, mobile threading dislocations tend to be lost very rapidly in (0001) GaN, often with little or no reduction in the immobile dislocation density. The capture radius for threading dislocation interactions is estimated to be approximately 40 nm using cross section transmission electron microscopy of dislocation filtering structures in GaAs monolithically grown on Si. We find that the minimum threading dislocation density that can be obtained in any given structure is likely to be limited by kinetic effects to approximately 10{sup 4}–10{sup 5 }cm{sup −2}.

• OSTI ID: 22314593
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 6 Vol. 116; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
APPROXIMATIONS
CAPTURE
CROSS SECTIONS
DECAY
DENSITY
DISLOCATIONS
EPITAXY
FCC LATTICES
FILTERS
GALLIUM ARSENIDES
GALLIUM NITRIDES
LAYERS
MIXTURES
MONOCRYSTALS
REDUCTION
STRAINS
TRANSMISSION ELECTRON MICROSCOPY