Electrical properties and transport mechanisms of Au/Ba0.6Sr0.4TiO3/GaN metal–insulator–semiconductor (MIS) diode at high temperature range

The electrical and transport mechanisms of a fabricated Au/Ba0.6Sr0.4TiO3 (BST)/GaN metal–insulator–semiconductor (MIS) diode have been studied in the temperature range of 280–430 K by current–voltage (I–V) and capacitance–voltage (C–V) measurements. The barrier heights (BHs) of the Au/BST/GaN MIS diode are found to be 0.85 eV (I–V)/1.35 (C–V) at 280 K and 1.14 eV (I–V)/1.17 (C–V) at 430 K. The series resistance (RS) values determined by Cheung’s functions are in good agreement with each other. The difference between BHs estimated by I–V and C–V methods are also discussed. Results show that the estimated interface state density (NSS) of MIS diode decreases with an increase in temperature. Observations have indicated that the BH increases whereas ideality factor RS and NSS decreases with increasing temperature. Results have demonstrated that the reverse leakage current is dominated by Poole–Frenkel emission at temperatures of 280–340 K and by Schottky emission at temperatures of 370–430 K. It is also noted that there is a transition of the conduction mechanism in Au/BST/GaN MIS diode from Poole–Frenkel to Schottky emission at temperatures of 340–370 K.