Improved reverse blocking characteristics in AlGaN=GaN Schottky barrier diodes based on AlN template

AlGaN/GaN-based planer Schottky barrier diodes (SBDs) with circular anode configuration were formed on AIN template and on sapphire. SBDs formed on AIN template exhibited clearly improved reverse-blocking characteristics compared with SBDs formed on sapphire. This appears to be due to their high crystal quality realised as a result of using AIN template. Breakdown voltages in those SBDs increased with the anode-to-cathode spacing and reached a high value of approximately 3 kV at a gap-spacing of 50 mum for SBDs formed on AIN template.