Microstructural evaluation of strained multilayer InAsSb/InSb infrared detectors by transmission electron microscopy

Journal Article · Sat May 01 04:00:00 EDT 1993 · Journal of Applied Physics; (United States)

DOI:https://doi.org/10.1063/1.352802· OSTI ID:6630690

Chadda, S; Datye, A ^[1]; Dawson, L R ^[2]

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1. Department of Chemical Engineering, University of New Mexico, Albuquerque, New Mexico 87131 (United States)
2. Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

InSb/InAsSb strained layer superlattices (SLS) were grown on (001) InSb substrates by molecular beam epitaxy at 425 [degree]C. The active device consisted of an InAs[sub 0.15]Sb[sub 0.85]/InSb superlattice region embedded within a [ital p]-[ital i]-[ital n] junction. The large lattice mismatch between the active device and the substrate required the growth of a buffer. InAs[sub 0.15]Sb[sub 0.85]/InSb SLS, where the average As content was gradually increased, was used as a buffer. The buffer structure was varied to probe its microstructural effect on the capping device. Three distinct approaches (A, B, and C) were used to grow the buffer. Approach A was a four-step buffer where the average content of As in the superlattice was increased in four equal composition steps. This approach led to a crystal with an extensive network of threading dislocations and microcracks. Approach B was to change the average composition in five equal composition steps, thereby decreasing the misfit at the interfaces between composition steps. This led to a decrease in the threading dislocation density but microscopic cracks were still evident. The last approach (C) was to employ migration enhanced epitaxy (MEE) for the growth of the five-step buffer. Samples grown by employing MEE revealed no microcracks but they contained a high density of unusual wiggly'' dislocations at the buffer/device interface. Detailed microstructural analysis by transmission electron microscopy is presented.

• OSTI ID: 6630690
• Journal Information: Journal of Applied Physics; (United States), Journal Name: Journal of Applied Physics; (United States) Vol. 73:9; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360606* -- Other Materials-- Physical Properties-- (1992-)
440100 -- Radiation Instrumentation
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
ANTIMONIDES
ANTIMONY COMPOUNDS
ARSENIC COMPOUNDS
ARSENIDES
CRYSTAL STRUCTURE
ELECTROMAGNETIC RADIATION
ELECTRON MICROSCOPY
EPITAXY
INDIUM ANTIMONIDES
INDIUM ARSENIDES
INDIUM COMPOUNDS
INFRARED RADIATION
MEASURING INSTRUMENTS
MICROSCOPY
MICROSTRUCTURE
MOLECULAR BEAM EPITAXY
PNICTIDES
RADIATION DETECTORS
RADIATIONS
STRAINS
SUPERLATTICES
TRANSMISSION ELECTRON MICROSCOPY