GaN/SiC and Al0.25Ga0.75 N/SiC heterojunction diodes were fabricated using Al/Ti for p-ohmic contact to the SiC and Ti/Al/Pt/Au for n-ohmic contact to the GaN and AlGaN. Annealing at 850 °C for 20 s (GaN) or 120 s (AlGaN) was required for achieving specific contact resistances in the 10-6 Ωcm2 range. The reverse breakdown voltage showed a negative temperature coefficient in both types of sample, with value ∼5.5 ± 2.5 × 10-3 V/K. The I-V characteristics of both heterojunctions show evidence of tunneling via defect states.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry