Surface preparation of freestanding GaN substrates for homoepitaxial GaN growth by rf-plasma MBE

David F. Storm, Thomas O. McConkie, Matthew T. Hardy, D. Scott Katzer, Neeraj Nepal, David J. Meyer, David Smith

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11 Scopus citations


The authors have investigated different methods for preparing the surfaces of freestanding, Ga-polar, hydride vapor-phase epitaxy grown GaN substrates to be used for homoepitaxial GaN growth by plasma-assisted molecular beam epitaxy (MBE). Cross-sectional transmission electron microscopy and secondary ion mass spectroscopy, respectively, were used to characterize the microstructure and to measure the concentrations of impurities unintentionally incorporated in the MBE-grown homoepitaxial GaN layers. Heating Ga-polar substrates to ∼1100 °C is as effective as a wet chemical clean for reducing impurity concentrations of oxygen, silicon, and carbon. The combination of an aggressive ex situ wet chemical clean with in situ Ga deposition and thermal desorption results in homoepitaxial GaN layer growth with very low residual impurity concentrations and without generating additional threading dislocations.

Original languageEnglish (US)
Article number02B109
JournalJournal of Vacuum Science and Technology B: Nanotechnology and Microelectronics
Issue number2
Publication statusPublished - Mar 1 2017


ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Instrumentation
  • Process Chemistry and Technology
  • Surfaces, Coatings and Films
  • Materials Chemistry
  • Electrical and Electronic Engineering

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