Characterization of Pd/Ni/Au ohmic contacts on p-GaN

H. K. Cho, T. Hossain, J. W. Bae, I. Adesida

Research output: Contribution to journalArticlepeer-review

31 Citations (Scopus)

Abstract

A low-resistance ohmic contact to Mg-doped p-type GaN grown by metal-organic chemical vapor deposition (MOCVD) with a carrier concentration of 2 × 1017 cm-3 using Pd/Ni/Au metallization was formed. An anneal at 500 °C for 1 min in a flowing N2 ambient produced an excellent ohmic contact with a specific contact resistivity as low as 2.4 × 10-5 Ω cm2. X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) depth profiles of Pd/Ni/Au contacts annealed at 500 °C demonstrated a strong correlation between Ni and Pd interdiffusion toward the GaN surface and a reduction in specific contact resistance. The low contact resistance is attributed to the reduction of the native oxide by Ni diffusion along with the formation of Pd and Ni related-gallide phases at the p-GaN surface region.

Original languageEnglish
Pages (from-to)774-778
Number of pages5
JournalSolid-State Electronics
Volume49
Issue number5
DOIs
Publication statusPublished - May 2005

Keywords

  • Contact resistance
  • GaN
  • Intermetallic compounds
  • Ni
  • Pd

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering
  • Materials Chemistry

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