Atomic intermixing in short-period InAs/GaSb superlattices

Journal Article · Mon Jun 11 04:00:00 EDT 2012 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4729058· OSTI ID:22080387

Ashuach, Y; Kauffmann, Y; Amouyal, Y; Zolotoyabko, E ^[1]; Isheim, D; Seidman, D N ^[2]

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1. Department of Materials Engineering, Technion - Israel Institute of Technology, Haifa 32000 (Israel)
2. Department of Materials Science and Engineering and Northwestern University Center for Atom-Probe Tomography, Northwestern University, Evanston, Illinois 60208 (United States)

High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) and laser-assisted local-electrode atom-probe (LEAP) tomography are utilizing for characterizing short-period InAs/GaSb superlattices with an emphasis on obtaining the atomic concentration profiles with sub-nm resolution. HAADF-STEM permits direct visualization and counting of atomic columns in individual sub-layers. The spatial resolution of HAADF-STEM is sufficient to resolve the anion-cation dumbbells and, on this basis, to follow the atomic distributions across a superlattice. Both methods confirm that InAs-on-GaSb interfaces are wider than GaSb-on-InAs interfaces. The interfacial widths deduced from LEAP tomographic measurements are slightly larger than those extracted from HAADF-STEM micrographs, with the maximum total width not exceeding 4.5 monolayers. LEAP tomographic analysis shows the presence of about 7 at. % of Sb atoms in the middle of the InAs sub-layers, as a result of As/Sb substitutions during growth.

• OSTI ID: 22080387
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 24 Vol. 100; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ATOMS
DISTRIBUTION
GALLIUM ANTIMONIDES
INDIUM ARSENIDES
INTERFACES
LASER MATERIALS
LASER RADIATION
LAYERS
MOLECULAR BEAM EPITAXY
SCANNING ELECTRON MICROSCOPY
SEMICONDUCTOR MATERIALS
SPATIAL RESOLUTION
SUPERLATTICES
TOMOGRAPHY
TRANSMISSION ELECTRON MICROSCOPY