Fully vertical AlN-on-SiC heterojunction diodes

We demonstrated fully vertical heterojunction diodes (HJDs) featuring a Mg-doped AlN layer directly grown on an n -type 4H-SiC substrate by metal-organic chemical vapor deposition. The electrical activation of the Mg-doped AlN layer was performed at 900 °C. At room temperature, the specific contact resistivity of the Mg-doped GaN/Mg-doped AlN structure was 6 × 10 −3 Ω cm 2 . In the AlN-on-SiC HJD, rectifying characteristics were obtained from 25 °C to 500 °C, exhibiting a rectification ratio exceeding 10 2 . Reducing trap states and dislocations in the AlN layer would improve the device performance of the fully vertical AlN-based diodes.