We have investigated a low-resistance thermally stable Pd/Re ohmic contact on moderately doped p-GaN:Mg (1.1 × 1017 cm-3). It is shown that the I-V characteristic of the as-deposited sample is improved upon annealing at 550 °C for 1 min under N2 ambient. However, annealing the sample at 650 °C results in the degradation of the I-V behaviour. Specific contact resistance as low as 8.7 × 10-4 ω cm2 is obtained from the Pd(20 nm)/Re(25 nm) contact annealed at 550 °C. It is also shown that the contact exhibits thermal stability during annealing at 550 °C. Auger electron microscopy and glancing angle x-ray diffraction studies are carried out to characterize interfacial reactions between the Pd/Re contacts and the GaN.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry