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 language | English (US) |
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Pages (from-to) | 1-5 |
Number of pages | 5 |
Journal | Journal of Electronic Materials |
DOIs | |
State | Accepted/In press - Dec 29 2015 |
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