Demonstration of Al0.3Ga0.7N quasi-vertical Schottky barrier diodes with average breakdown electric field over 2 MV cm−1

Abstract

The Al0.3Ga0.7N quasi-vertical Schottky barrier diodes on sapphire have been fabricated. The Al0.3Ga0.7N SBDs exhibit an excellent rectification behavior with a turn-on voltage of 1.03 V, a high on/off ratio of ∼109 and a low ideality factor of 1.22. The Al0.3Ga0.7N SBDs also present a high breakdown voltage of 64 V with a 0.3 μm thick drift layer and a record high average breakdown electric field E av of 2.13 MV cm−1, which is the best achieved among vertical GaN, Al x Ga1−x N and AlN SBDs. Furthermore, the devices exhibit excellent thermal stability, showing great potential in high-voltage, high-power and high-temperature applications.