Low-resistance and thermally stable Pd/Ru ohmic contacts to p-type GaN

Ja Soon Jang, Chang Won Lee, Seong Ju Park, Tae Yeon Seong, I. T. Ferguson

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10 Citations (Scopus)


We report on low-resistance and thermally stable Pd/Ru ohmic contacts to surface-treated p-GaN (3 × 1017 cm-3). It is shown that annealing at 500°C for 2 min in a N2 ambient improves ohmic contact properties. Specific contact resistance is measured to be 9.2(±0.2) × 10-4 and 2.4(±0.2) × 10-5 Ωcm2 for the as-deposited and annealed samples, respectively. Atomic force microscopy results show that the surfaces of both the contacts are remarkably smooth with a root-mean-square (rms) roughness of about 0.6 nm. The current-voltage-temperature (I-V-T) and calculation results indicate that, for the as-deposited contact, thermionic field emission is dominant, while for the annealed contact, field emission dominates the current flow.

Original languageEnglish
Pages (from-to)903-906
Number of pages4
JournalJournal of Electronic Materials
Issue number9
Publication statusPublished - 2002 Sep 1
Externally publishedYes



  • Gallium nitride
  • Ohmic contact
  • Schottky barrier
  • Specific contact resistance
  • Surface Fermi level

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials
  • Materials Science(all)
  • Physics and Astronomy (miscellaneous)

Cite this

Jang, J. S., Lee, C. W., Park, S. J., Seong, T. Y., & Ferguson, I. T. (2002). Low-resistance and thermally stable Pd/Ru ohmic contacts to p-type GaN. Journal of Electronic Materials, 31(9), 903-906.