Electrical characterization of Ni/Al0.09Ga0.91N Schottky barrier diodes as a function of temperature

The current-voltage characteristics (I-V) of Ni/Al0.09Ga0.91N Schottky barrier diodes (SBDs) prepared with a photolithography and lift-off techniques were investigated in the wide temperature range of 100-310 K. The I-V characteristics of the devices were analyzed on the basis of the thermionic emission (TE) theory. An abnormal decrease in the experimental effective barrier height and an increase in ideality factor with a decrease in the temperature were observed. The temperature dependence of the effective Schottky barrier height (SBH) was explained with the presence of the laterally barrier height inhomogeneity at the metal-semiconductor interface. In addition, the modified Richardson plots were used to determine experimental Richardson constants in the three temperature regions.