Atomic structure of dissociated 60° dislocations in GaAs/GaAs0.92Sb0.08/GaAs heterostructures

SCRIPTA MATERIALIA

卷:153

Article

Gangopadhyay, Abhinandan¹  Maros, Aymeric²  Faleev, Nikolai²  Smith, David J.³ 

[1] Arizona State Univ, Sch Engn Matter Transport & Energy, Tempe, AZ 85287 USA

[2] Arizona State Univ, Sch Elect Comp & Energy Engn, Tempe, AZ 85287 USA

[3] Arizona State Univ, Dept Phys, Tempe, AZ 85287 USA

关键词: Stacking faults;    Dislocations;    HAADF-STEM;    Heterostructures;    Compound semiconductors;   

DOI  :  10.1016/j.scriptamat.2018.04.050

来源: Elsevier

【 摘 要 】

Dissociated 60 degrees dislocations in low-misfit GaAs/GaAs0.92Sb0.08/GaAs (001) heterostructures are investigated using aberration-corrected scanning transmission electron microscopy. Intrinsic stacking faults bounded by 30 degrees and 90 degrees Shockley partial dislocations are created at the compressively-strained film/substrate interface and the tensile-strained cap/film interface. Unpaired atomic columns are clearly observed at the cores of the 30 degrees partial dislocations for most stacking faults. Comparison with atomic structural models establishes that these dissociated 60 degrees dislocations belong primarily to glide set. For both interface types, the leading partial is located in the constraining layer whereas the trailing partial is located in the layer undergoing strain relaxation. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

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