CONTROL OF GRAIN-STRUCTURE OF LASER-DEPOSITED (BA, SR)TIO3 FILMS TO REDUCE LEAKAGE CURRENT

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 propo sed. This includes the deposition of amorphous BSTO at 500 degrees C a nd annealing of the amorphous films at 650 degrees C in O-2 for crysta llization. The leakage current of the film produced from the amorphous one was significantly lower than that of BSTO films deposited directl y at the substrate temperature of 650 degrees C. The crystalline struc ture of the film produced from the amorphous one was found to be circu lar. In contrast, as-grown crystalline film showed columnar grain stru ctures. The reduction of the leakage current may be attributed to the differences in the grain structures.