Barrier lowering and leakage current reduction in Ni-AlGaN/GaN Schottky diodes with an oxygen-treated GaN cap layer

Hyeonseok Woo, Jongkyong Lee, Yongcheol Jo, Jaeseok Han, Jongmin Kim, Hyungsang Kim, Cheong Hyun Roh, Jun Ho Lee, Jung ho Park, Cheol Koo Hahn, Hyunsik Im

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Abstract

We report on the effect of oxygen annealing for GaN surface on the Schottky barrier configuration and leakage current in Ni-AlGaN/GaN Schottky barrier diodes. After oxygen annealing, their turn-on voltage and reverse-bias leakage current characteristics are significantly improved due to a reduction in the Schottky barrier height (SBH) and suppression in the surface states respectively. Interface state density extracted from the Terman method was reduced by 2 orders of magnitude. X-ray photoelectron spectroscopy measurements show that the oxygen annealing induces Ga2O3 on the GaN surface. The formation of Ga2O3 reduces the interface state density as well as lowers the SBH through the modification of hybridized metal induced gap states.

Original languageEnglish
Pages (from-to)1027-1031
Number of pages5
JournalCurrent Applied Physics
Volume15
Issue number9
DOIs
Publication statusPublished - 2015 Jun 29

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Keywords

  • AlGaN/GaN device
  • Interface state density
  • Oxygen annealing
  • Schottky barrier diode
  • Surface treatment
  • Turn-on voltage

ASJC Scopus subject areas

  • Materials Science(all)
  • Physics and Astronomy(all)

Cite this

Woo, H., Lee, J., Jo, Y., Han, J., Kim, J., Kim, H., Roh, C. H., Lee, J. H., Park, J. H., Hahn, C. K., & Im, H. (2015). Barrier lowering and leakage current reduction in Ni-AlGaN/GaN Schottky diodes with an oxygen-treated GaN cap layer. Current Applied Physics, 15(9), 1027-1031. https://doi.org/10.1016/j.cap.2015.06.004