Over 1.0 kV GaN p–n junction diodes on free‐standing GaN substrates

Abstract

AbstractThis report describes the fabrication and characteristics of GaN p–n junction diodes on free‐standing GaN substrates with low dislocation density. We have demonstrated GaN p–n junction diodes with a unique field‐plate (FP) structure. The breakdown voltage VB is further improved due to the FP structure and the low dislocation density. The breakdown voltage of a diode of 60 µm in diameter with the FP structure is over −1000 V, and the leakage current is below 10−9 A until reaching the breakdown voltage. Even in larger diodes (100 and 200 µm in diameter) with FP, the breakdown voltage is over −800 V. However, the specific on‐resistance Ron is high due to damage by the plasma process of sputtering. The specific on‐resistance is further improved due to using a low damage passivation film. As a result, a specific on‐resistance of 1.2 mΩ · cm2 is obtained.