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Title: Electrical and structural characteristics of metamorphic In{sub 0.38}Al{sub 0.62}As/In{sub 0.37}Ga{sub 0.63}As/In{sub 0.38}Al{sub 0.62}As HEMT nanoheterostructures

The influence of the metamorphic buffer design and epitaxial growth conditions on the electrical and structural characteristics of metamorphic In{sub 0.38}Al{sub 0.62}As/In{sub 0.37}Ga{sub 0.63}As/In{sub 0.38}Al{sub 0.62}As high electron mobility transistor (MHEMT) nanoheterostructures has been investigated. The samples were grown on GaAs(100) substrates by molecular beam epitaxy. The active regions of the nanoheterostructures are identical, while the metamorphic buffer In{sub x}Al{sub 1-x}As is formed with a linear or stepwise (by {Delta}{sub x} = 0.05) increase in the indium content over depth. It is found that MHEMT nanoheterostructures with a step metamorphic buffer have fewer defects and possess higher values of two-dimensional electron gas mobility at T = 77 K. The structures of the active region and metamorphic buffer have been thoroughly studied by transmission electron microscopy. It is shown that the relaxation of metamorphic buffer in the heterostructures under consideration is accompanied by the formation of structural defects of the following types: dislocations, microtwins, stacking faults, and wurtzite phase inclusions several nanometers in size.
Authors:
; ; ; ;  [1] ;  [2] ;  [1] ; ;  [2]
  1. Russian Academy of Sciences, Institute of Ultrahigh Frequency Semiconductor Electronics (Russian Federation)
  2. Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)
Publication Date:
OSTI Identifier:
22210417
Resource Type:
Journal Article
Resource Relation:
Journal Name: Crystallography Reports; Journal Volume: 58; Journal Issue: 6; Other Information: Copyright (c) 2013 Pleiades Publishing, Inc.; http://www.springer-ny.com; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 77 NANOSCIENCE AND NANOTECHNOLOGY; ABSORPTION SPECTROSCOPY; BUFFERS; DISLOCATIONS; ELECTRON MOBILITY; GALLIUM ARSENIDES; MOLECULAR BEAM EPITAXY; STACKING FAULTS; SUBSTRATES; TRANSMISSION ELECTRON MICROSCOPY; X-RAY SPECTROSCOPY