Control of Buffer-Induced Current Collapse in AlGaN/GaN HEMTs Using SiNx Deposition

William M. Waller*, Mark Gajda, Saurabh Pandey, Johan J.T.M. Donkers, David Calton, Jeroen Croon, Jan Sonsky, Michael J. Uren, Martin Kuball

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)

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The stoichiometry of low-pressure chemical vapor deposition SiNx surface passivation is shown to change vertical conductivity at the top of the epitaxial stack in GaN-on-Si power high-electron mobility transistors (HEMTs). This changes the charge stored in the carbon-doped GaN layer during high-voltage operation, and allows direct control of buffer-related current collapse in HEMTs. Substrate bias ramps are used to identify the changes in C:GaN charge trapping and vertical leakage. Channel length dependence indicates a lateral conductivity in the C:GaN with a localized increase in vertical conductivity under the ohmic contacts. An optimum SiNx recipe is identified which simultaneously delivers low current collapse and low drain leakage.

Original languageEnglish
Article number8013764
Pages (from-to)4044-4049
Number of pages6
JournalIEEE Transactions on Electron Devices
Issue number10
Early online date21 Aug 2017
Publication statusPublished - 1 Oct 2017

Structured keywords

  • CDTR


  • AlGaN/GaN
  • buffer trapping
  • high-electron mobility transistor (HEMT)
  • passivation

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    Waller, W. M., Gajda, M., Pandey, S., Donkers, J. J. T. M., Calton, D., Croon, J., Sonsky, J., Uren, M. J., & Kuball, M. (2017). Control of Buffer-Induced Current Collapse in AlGaN/GaN HEMTs Using SiNx Deposition. IEEE Transactions on Electron Devices, 64(10), 4044-4049. [8013764].