Investigations on the nonidealities in Pd/n-GaN schottky diodes grown by MOCVD

Effect of ammonia flow rate on the device characteristics of Pd/n-GaN Schottky diodes is discussed. Concentration of the compensating defects and the threading dislocation was found to increase with increase of V/III ratio. Current-Voltage (I-V) barrier height varies from 0.75 eV to 0.98 e V. The ideality factor and leakage current decreases with increase in V/III ratio. Large variation in the slope of the lines of A²/C² vs. V plot was observed. I-V-T measurements revealed that the ideality factor and reverse leakage current increases with temperature confirming that the conduction mechanism is through trap assisted tunnelling process or deep center hopping conduction. The effect of V/III ratio induced lattice defects on the nonideal behaviour of GaN schottky diodes was studied and a possible mechanism responsible for the variations has been discussed.