High-Voltage AlGaN/GaN Schottky Barrier Diodes on Si Substrate with Low-Temperature GaN Cap Layer for Edge Termination

AlGaN/GaN Schottky barrier diodes (SBDs) using a low-temperature- (LT-) GaN cap layer to provide edge termination, thus increasing the breakdown voltage and suppressing current collapse, were developed and fabricated on cost-effective, 100-mm-diameter Si (111) substrates. The SBDs fabricated with the LT-GaN/AlGaN/GaN heterostructure had a reverse leakage current three orders lower than that of conventional AlGaN/GaN SBDs and a high breakdown voltage of 1000 V. The effect of the LT-GaN cap layer on current collapse in the fabricated SBDs was also studied. Even under a pulse-mode bias stress of -200 V, no significant current collapse was observed.