GaN Schottky Diodes for Microwave Power Rectification

A GaN Schottky diode with a lateral structure for microwave power rectification was developed on a semi-insulating silicon carbide substrate. Device evaluation showed that the turn-on voltage was around 0.8 V. The on-resistance of the diode with one finger was 25.6 Ω, the breakdown voltages for those with the field plate reached 93 V, for the wafer with a doping level of 4.0 × 10 16 cm -3 . The forward and reverse characteristics became stabilized after surface etching. RF measurement at 2.45 GHz showed that the capacitance of the diode was about 0.29 pF at a bias of 0 V. The value is satisfactorily small for microwave rectification. If the superior material characteristics of GaN are fully utilized, GaN Schottky diodes will play key roles in microwave power transmission applications.