High-Performance AlGaN/GaN Schottky Diodes With an AlGaN/AlN Buffer Layer

High-performance AlGaN/GaN Schottky barrier diodes are fabricated on a composite AlGaN/AlN buffer layer with low screw-type and high edge-type dislocation densities. Without edge termination, the devices with 30-μm anode-to-cathode spacing exhibit a high breakdown voltage (VB) of 3489 V, a low leakage current (IR) of less than 0.2 μA at -2000 V, and a low specific on-resistance (Ron) of 7.9 mΩ·cm2, resulting in a figure of merit (VB2/Ron) as high as 1.54 GW/cm2. Their switching characteristics as revealed by the reverse-recovery transient waveform exhibit a short reverse-recovery time of 17 ns.