Surface morphology and electronic properties of dislocations in AlGaN/GaN heterostructures

J. W.P. Hsu, M. J. Manfra, D. V. Lang, K. W. Baldwin, L. N. Pfeiffer, R. J. Molnar

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17 Scopus citations


Scanning force microscopy was used to examine the surfaces of AlGaN/GaN heterostructures grown by molecular beam epitaxy (MBE) on GaN templates prepared by hydride vapor phase epitaxy (HVPE). Away from dislocations, the MBE growth replicates the surface morphology of the HVPE film, with monolayer steps clearly visible in topographic images. However, the surface morphology near dislocations depends strongly on the MBE growth conditions. Under Ga rich growth the dislocations appear as hillocks, while under stoichiometric growth they appear as pits. A dependence on Al concentration is also observed. Surface contact potential variation near dislocations is consistent with excess negative charges surrounding by a depletion region, but this was observed only for the film grown under stoichiometric conditions.

Original languageEnglish (US)
Pages (from-to)110-114
Number of pages5
JournalJournal of Electronic Materials
Issue number3
StatePublished - Mar 2001
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Materials Chemistry
  • Electrical and Electronic Engineering


  • AlGaN/GaN heterostructures
  • Dislocations
  • Surface contact potential
  • Surface morphology


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