Strain relief and AlSb buffer layer morphology in GaSb heteroepitaxial films grown on Si as revealed by high-angle annular dark-field scanning transmission electron microscopy

Journal Article · Mon Feb 21 00:00:00 EST 2011 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.3551626· OSTI ID:21518293

Vajargah, S Hosseini; Couillard, M; Cui, K ^[1]; Tavakoli, S Ghanad; Robinson, B; Kleiman, R N; Preston, J S ^[2]; Botton, G A ^[1]

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1. Department of Material Science and Engineering, McMaster University, 1280 Main St. W., Hamilton, Ontario L8S 4M1 (Canada)
2. Department of Engineering Physics, McMaster University, Hamilton, Ontario L8S 4M1 (Canada)

The interfacial misfit (IMF) dislocation array of an epitaxial GaSb film on a Si substrate has been imaged with high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). The mismatch strain accommodation through dislocation formation has been investigated using geometric phase analysis (GPA) on HAADF-STEM images with atomic resolution to probe the defects' local strain distribution. These measurements indicate that the lattice parameter of the epitaxial film recovers its bulk value within three unit cells from the interface due to the relaxation through IMF dislocations. The atomic number contrast of the HAADF-STEM images and energy dispersive x-ray spectrometry illustrate the formation of islands of AlSb buffer layer along the interface. The role of the AlSb buffer layer in facilitating the GaSb film growth on Si is further elucidated by investigating the strain field of the islands with the GPA.

• OSTI ID: 21518293
• Journal Information: Applied Physics Letters, Vol. 98, Issue 8; Other Information: DOI: 10.1063/1.3551626; (c) 2011 American Institute of Physics; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM COMPOUNDS
ANTIMONIDES
ATOMIC NUMBER
DISLOCATIONS
GALLIUM ANTIMONIDES
LATTICE PARAMETERS
LAYERS
MOLECULAR BEAM EPITAXY
PHASE STUDIES
RELAXATION
SCANNING ELECTRON MICROSCOPY
SEMICONDUCTOR MATERIALS
SILICON
STRAINS
SUBSTRATES
SURFACES
TRANSMISSION ELECTRON MICROSCOPY
X RADIATION
X-RAY SPECTROSCOPY
ANTIMONY COMPOUNDS
CRYSTAL DEFECTS
CRYSTAL GROWTH METHODS
CRYSTAL STRUCTURE
ELECTROMAGNETIC RADIATION
ELECTRON MICROSCOPY
ELEMENTS
EPITAXY
GALLIUM COMPOUNDS
IONIZING RADIATIONS
LINE DEFECTS
MATERIALS
MICROSCOPY
PNICTIDES
RADIATIONS
SEMIMETALS
SPECTROSCOPY