Temperature-dependent reverse leakage current characterization of n-GaN Schottky diodes

n-GaN Schottky barrier diodes were fabricated on a sapphire substrate. Ni/Au and Ti/Al/Mo/Au were used for Schottky and ohmic contacts, respectively. A better fitted characteristic was obtained by calculation of thermionic-field emission. Similar comparison was made for current-voltage characteristics measured at high temperatures up to 523 K. With the increase in the device temperature, better fitting was obtained with a thermionic emission theory.