Formation mechanism of volcano-like structural defects in multiple periods of InAs quantum dots on GaAs

Hwack Joo Lee, Hyun Ryu, Sahn Nahm

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11 Citations (Scopus)


Studies on detailed formation mechanisms of volcano-like structural defects on 20 periods of InAs quantum dots on a GaAs substrate grown by molecular-beam-epitaxy system were carried out by microstructural examinations with high-resolution transmission electron microscopy. The volcano-like structure has started to be formed through the wave-like modulation of the growth surface mainly caused by the gradients in the surface chemical potential. Considerable retardation of growth has occurred and a deep valley is formed inside the structure and the width of a fully grown structure has reached 100 nm. The extensive growth competition between quantum dot structure and volcano-like structure has also occurred in the area where the changes of curvature are large. A spinodally decomposed structure has formed inside the defect whose wavelength of modulation is initially in the [1 1 1] direction, reflecting the initial inclined surface profile, and then changed to the [1 1 0] direction as growth time goes on from the bottom of the structure. This means that the modulated structure has revealed the structure far from the equilibrium state.

Original languageEnglish
Pages (from-to)292-298
Number of pages7
JournalJournal of Crystal Growth
Issue number3-4
Publication statusPublished - 1997 Dec

Bibliographical note

Funding Information:
This research was supported by the Korean Ministry of Science and Technology through the project for the reinforcement of new materials evaluation technique in 1996.


  • Evolution of surface
  • Multiply stacked structure
  • Quantum dot
  • Spinodal decomposition
  • Volcano-like structure

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Inorganic Chemistry
  • Materials Chemistry


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