Electrical characterization of Au/n-GaN Schottky diodes

The current–voltage characteristics of Au/n-GaN Schottky diodes were determined in the temperature range 80–300 K. Analysis of the measured characteristics at room temperature allows the determination of the electrical parameters, the saturation current Is, the ideality factor n and the serial resistance Rs are equal to 1.9×10−11 A, 1.18 and 65 Ω, respectively. The leakage current is 380 μA at a reverse bias voltage of −10 V. The zero-bias barrier height for current transport decreases and the ideality factor increases at low temperature. The flat band barrier height is determined at room temperature and is evaluated to be 0.98 eV by the current–voltage method and is equal to 1.02 eV by the capacitance–voltage technique. The built in potential and the ionized donor concentration of GaN are determined to be 0.925 eV and 7.75×1016 cm−3, respectively, from the capacitance–voltage measurements under reverse bias.