Correlating elemental compositions and charge carrier profiles in ultra-pure GaN/AlGaN stacks grown by molecular beam epitaxy

Research output: Contribution to journalResearch articleContributedpeer-review


  • Stefan Schmult - , Chair of Nanoelectronics (Author)
  • Pascal Appelt - , TUD Dresden University of Technology, NaMLab - Nanoelectronic materials laboratory gGmbH (Author)
  • Claudia Silva - , NaMLab - Nanoelectronic materials laboratory gGmbH (Author)
  • Steffen Wirth - , Max Planck Institute for Chemical Physics of Solids (Author)
  • Andre Wachowiak - , NaMLab - Nanoelectronic materials laboratory gGmbH (Author)
  • Andreas Großer - , NaMLab - Nanoelectronic materials laboratory gGmbH (Author)
  • Thomas Mikolajick - , Chair of Nanoelectronics, NaMLab - Nanoelectronic materials laboratory gGmbH (Author)


Inconsistencies in the concentrations of unintentional donor impurities and free charge carriers in GaN/AlGaN layer stacks hosting a two-dimensional electron gas (2DEG) can be attributed to the measurement procedure and solely depend on the way in which the free charge carrier concentration is extracted. Particularly, when the 2DEG acts as the bottom electrode in capacitance versus voltage measurements, unphysically low concentrations of free charges are calculated. This originates from the depletion of the 2DEG and the accompanying disappearance of the bottom electrode. It is shown that, for the case of a defined (non-vanishing) bottom electrode, the levels of donor impurities and resulting free charges consistently match.


Original languageEnglish
Article number042702
Number of pages5
JournalJournal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
Issue number4
Publication statusPublished - 1 Jul 2023

External IDs

WOS 000987889100001
ORCID /0000-0003-3814-0378/work/142256362


DFG Classification of Subject Areas according to Review Boards

Subject groups, research areas, subject areas according to Destatis


  • Electron-mobility transistors, Gan

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