Identification of dark-line defects in AlGaAs/InGaAs/GaAs heterostructures

Journal Article · Sun May 15 00:00:00 EDT 1988 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.340434· OSTI ID:5254324

Fitzgerald, E A; Ashizawa, Y; Eastman, L F; Ast, D G

We have investigated the correlation between the structure of and the nonradiative recombination at defects in AlGaAs/InGaAs/GaAs heterostructures using scanning cathodoluminescence (CL) and transmission electron microscopy (TEM). It is shown that the dark-line defects seen in scanning CL images do not always correspond to individual misfit dislocations even for relatively low mismatched epilayers. CL and TEM images from the same area reveal that there are structures which do correlate to the dark lines seen in CL. The density of dislocations at the interface determines which structure dominates the CL image. At very low misfit, the dark lines correspond to single 60/sup 0/ or edge dislocations, whereas at higher misfit the dark lines correspond to groups of dislocations. Contrary to previous studies in GaAlAsP/GaAlAs semiconductor heterostructures (J. Microsc. 118, 255 (1980)), we have found that edge dislocations at AlGaAs/InGaAs and InGaAs/GaAs interfaces are higher nonradiative recombination sites than 60/sup 0/ dislocations. TEM micrographs show that edge dislocations form more readily along one <110> direction, possibly explaining differences in residual elastic strain measurements along different <110> directions.

• Research Organization: Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853
• OSTI ID: 5254324
• Journal Information: J. Appl. Phys.; (United States), Vol. 63:10
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ARSENIDES
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
GALLIUM ARSENIDES
INDIUM ARSENIDES
CATHODOLUMINESCENCE
EXPERIMENTAL DATA
INTERFACES
TRANSMISSION ELECTRON MICROSCOPY
ALUMINIUM COMPOUNDS
ARSENIC COMPOUNDS
ARSENIDES
DATA
ELECTRON MICROSCOPY
GALLIUM COMPOUNDS
INDIUM COMPOUNDS
INFORMATION
LUMINESCENCE
MICROSCOPY
NUMERICAL DATA
PNICTIDES
360602* - Other Materials- Structure &amp; Phase Studies