Morphology and defect structures of GaSb islands on GaAs grown by metalorganic vapor phase epitaxy

Joon Hyung Kim, Tae Yeon Seong, N. J. Mason, P. J. Walker

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The initial nucleation of GaSb on (001) GaAs substrates by metalorganic vapor phase epitaxy has been investigated using transmission electron microscopy (TEM) and high resolution electron microscopy (HREM). TEM results showed that the GaSb islands experience a morphological transition as the growth temperature increases. For growth at 520°C, the islands are longer along the [110] direction; at 540°C, they are nearly square, and at 560°C, they are longer along the [110] direction. Possible mechanisms are proposed to describe such a transition. TEM and HREM examination showed that lattice misfit relaxation mechanisms depend on the growth temperature. For the sample grown at 520°C, the lattice mismatch strain was accommodated mainly by 90° dislocations; for the sample grown at 540°C, the misfit strain was relieved mostly by 90° dislocations with some of 60° dislocations, and for the sample grown at 560°C, the strain was accommodated mainly by 60° dislocations which caused a local tilt of the GaSb islands with respect to the GaAs substrate. The density of threading dislocations was also found to be dependent on the growth temperature. Mechanisms are proposed to explain these phenomena.

Original languageEnglish
Pages (from-to)466-471
Number of pages6
JournalJournal of Electronic Materials
Issue number5
Publication statusPublished - 1998 May 1
Externally publishedYes



  • GaSb
  • High resolution electron microscopy (HREM)
  • Metalorganic vapor phase epitaxy (MOVPE)
  • Misfit dislocation
  • Transmission electron microscopy (TEM)

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Materials Science(all)
  • Electronic, Optical and Magnetic Materials
  • Physics and Astronomy (miscellaneous)

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