Abstract

We report on the temperature-dependent contact resistivity and high-temperature stability of the annealed Ni/Au ohmic contacts to p-type GaN in air. As the measure temperature increases from 25°C to 390°C, both the specific contact resistivity (ρc) and sheet resistance (Rsh) decrease by factors ∼10, contributing to the 10-fold increase in current at 390°C compared with that at 25°C. It was also observed that the ρc was further reduced by 36%, i.e., from 2.2 × 10−3 Ω cm2 to 1.4 × 10−3 Ω cm2, during the 48-h high-temperature stability test at 450°C in air, showing excellent stability of the contacts. An increase in ρc was observed after the contacts were subjected to 500°C in air. Higher temperature stress led to a significant increase in ρc. The contacts show rectifying I–V characteristics after being subjected to 700°C for 1 h. The degradation mechanics were analyzed with the assistance of transmission electron microscopy and energy dispersive x-ray spectroscopy.

Original languageEnglish (US)
Pages (from-to)1-5
Number of pages5
JournalJournal of Electronic Materials
DOIs
StateAccepted/In press - Dec 29 2015

    Fingerprint

Keywords

  • high-temperature electronics
  • Ni/Au ohmic contacts
  • p-type GaN
  • specific contact resistivity

ASJC Scopus subject areas

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

Cite this