High-performance AlN/GaN HEMTs on sapphire substrate with an oxidized gate insulator

Kelson D. Chabak, Dennis E. Walker, Michael R. Johnson, Antonio Crespo, Amir M. Dabiran, David Smith, Andrew M. Wowchak, Stephen K. Tetlak, Mauricio Kossler, James K. Gillespie, Robert C. Fitch, Manuel Trejo

Research output: Contribution to journalArticlepeer-review

35 Scopus citations


This letter presents transistor device results on ultrathin AlN/GaN high-electron mobility transistors grown on a sapphire substrate with high dc/RF performance, including low gate leakage and high transconductance. Devices with 80- and 180-nm T-gates are compared, which demonstrate drain-induced off -state gate leakage currents below 10-6 A/mm and extrinsic transconductance gm ∼ 500}\ mS/mm} by utilizing a ∼2-3 nm amorphous oxide layer formed under the T-gate during processing. In addition, excellent dc results such as RC < 0.50} mm} and pulsed IDSmax ∼ 1.75}\ A/mm} are reported. Small-signal RF performance using an 80-nm T-gate achieved ft>100 GHz} operation, which is among the best so far reported for AlN/GaN technology.

Original languageEnglish (US)
Article number6032708
Pages (from-to)1677-1679
Number of pages3
JournalIEEE Electron Device Letters
Issue number12
StatePublished - Dec 2011


  • Aluminum nitride
  • High-electron-mobility transistor (HEMT)
  • Lattice strain
  • Low gate leakage
  • Sapphire substrate

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering


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