P-InGaN/n-GaN Vertical Conducting Diodes on n+-SiC Substrate for High Power Electronic Device Applications

Abstract

We have investigated the current–voltage (I–V) characteristics of p-InGaN/n-GaN vertical conducting diodes grown on n+-SiC substrates by low-pressure metal organic vapor phase epitaxy (MOVPE). The breakdown voltage (VB) of 250 V was obtained with a low on-state resistance (Ron) of 1.28 mΩ cm2 when the n-GaN layer thickness was increased to 1800 nm, leading to the high figure-of-merit, (VB)2/Ron, of 49 MW/cm2. With increasing measurement temperature from room temperature (RT) to 520 K, the on-state resistance decreased due to the reduced contact resistance of the p-InGaN layer, while the breakdown voltage remained almost constant because of fewer defects in the n-GaN layer. These I–V characteristics are preferable for high-power and high-temperature electronic device applications.