Nature and origin of pure edge dislocations in low mismatched epitaxial structures

• Published in: Journal of crystal growth Vol. 172; no. 1; pp. 58 - 63
• Main Author: Vdovin, V.I.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-02-1997
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/S0022-0248(96)00734-8

A study of pure edge misfit dislocations (L-MDs) in
SiGe
Si
,
Ge
GaAs
,
GaAlAsP
GaAs
,
GaAlAsSb
GaSb
and
InGaAsP
InP
epitaxial structures grown by different techniques has been performed. A model for the formation of L-MDs from the parallel 60°-MDs pre-existing at the interface is proposed. The common dislocation node for these initial 60°-MDs, arising as a result of the dislocation reactions in crossing points of the MDs, is a starting point for L-MD generation. Initial MDs with appropriate Burgers vectors may be located at the interface at a distance of up to 0.5 μm apart. The process of L-MD propagation is accompanied by a shift of dislocations from the interface upwards into the epilayer or downwards into the substrate. The behavior of L-MDs is discussed in terms of dislocation mobility in the epitaxial layer at the growth temperature in heterostructures.