Effect of post-annealing on leakage currents of (Ba,Sr)TiO3 thin film prepared by pulsed laser deposition

The leakage conduction mechanisms of the Ba0.6Sr0.4TiO3 thin film prepared by pulsed laser deposition are investigated before and after post-annealing in oxygen ambient when the top Pt electrodes were deposited. An explanation for the transition of the leakage conduction mechanisms for the two cases is proposed in terms of the change of the Schottky barrier height in the top Pt/BST interface. The effect of the post-annealing is considered to be the enhancement of the Schottky barrier height, not only the elimination of oxygen vacancy in BST films as suggested by previous studies.