Effects of buffer layers on the structural and electronic properties of InSb films
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States)
We have investigated the effects of various buffer layers on the structural and electronic properties of n-doped InSb films. We find a significant decrease in room-temperature electron mobility of InSb films grown on low-misfit GaSb buffers, and a significant increase in room-temperature electron mobility of InSb films grown on high-misfit InAlSb or step-graded GaSb+InAlSb buffers, in comparison with those grown directly on GaAs. Plan-view transmission electron microscopy (TEM) indicates a significant increase in threading dislocation density for InSb films grown on the low-misfit buffers, and a significant decrease in threading dislocation density for InSb films grown on high-misfit or step-graded buffers, in comparison with those grown directly on GaAs. Cross-sectional TEM reveals the role of the film/buffer interfaces in the nucleation (filtering) of threading dislocations for the low-misfit (high-misfit and step-graded) buffers. A quantitative analysis of electron mobility and carrier-concentration dependence on threading dislocation density suggests that electron scattering from the lattice dilation associated with threading dislocations has a stronger effect on electron mobility than electron scattering from the depletion potential surrounding the dislocations. Furthermore, while lattice dilation is the predominant mobility-limiting factor in these n-doped InSb films, ionized impurity scattering associated with dopants also plays a role in limiting the electron mobility.
- OSTI ID:
- 20668200
- Journal Information:
- Journal of Applied Physics, Vol. 97, Issue 4; Other Information: DOI: 10.1063/1.1841466; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ALUMINIUM COMPOUNDS
CHARGE CARRIERS
COMPARATIVE EVALUATIONS
DISLOCATIONS
DOPED MATERIALS
ELECTRON DIFFRACTION
ELECTRON MOBILITY
GALLIUM ANTIMONIDES
GALLIUM ARSENIDES
IMPURITIES
INDIUM ANTIMONIDES
INTERFACES
LAYERS
NUCLEATION
POTENTIALS
TEMPERATURE RANGE 0273-0400 K
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY