High-temperature characteristics of Al(x)Gai(1-x)N/GaN Schottky diodes

High-temperature characteristics of the metal/Al(x)Gai(1-x)N/GaN M/S/S (M/S/S) diodes have been studied with current voltage (I-V) and capacitance voltage (C-V) measurements at high temperatures. Due to the presence of the piezoelectric polarization field and a quantum well at the Al(x)Gai(1-x)N/GaN interface, the Al(x)Gai(1-x)N/GaN diodes show properties distinctly different from those of the Al(x)Gai(1-x)N diodes. For the Al(x)Gai(1-x)N/GaN diodes, an increase in temperature accompanies an increase in barrier height and a decrease in ideality factor, while the Al(x)Gai(1-x)N diodes are opposite. Furthermore, at room temperature, both reverse leakage current and reverse breakdown voltage are superior for the Al(x)Gai(1-x)N/GaN diodes to those for the Al(x)Gai(1-x)N diodes.