Control of Grain Structure of Laser-Deposited (Ba, Sr)TiO3 Films to Reduce Leakage Current

Abstract
A new technique to realize a low leakage current of (Ba, Sr)TiO3 (BSTO) thin films by controlling the grain structure of BSTO has been proposed. This includes the deposition of amorphous BSTO at 500° C and annealing of the amorphous films at 650° C in O2 for crystallization. The leakage current of the film produced from the amorphous one was significantly lower than that of BSTO films deposited directly at the substrate temperature of 650° C. The crystalline structure of the film produced from the amorphous one was found to be circular. In contrast, as-grown crystalline film showed columnar grain structures. The reduction of the leakage current may be attributed to the differences in the grain structures.