CHARACTERIZATION OF SPUTTERED BARIUM STRONTIUM-TITANATE AND STRONTIUM-TITANATE THIN-FILMS

Sputtered Ba1-xSrxTiO3 (BST) and SrTiO3 (STO) films and capacitors mad e with these dielectrics have been characterized with respect to physi cal and electrical properties. Specific capacitance values included a high of 96 fF/mu m(2) for BST films deposited of 600 degrees C and a h igh of 26 fF/mu m(2) for STO films deposited at 400 degrees C. Leakage current densities at 3.3 V for the most part, varied from mid 10(-8) to mid 10(-6) A/cm(2). All of the dielectrics are polycrystalline, alt hough the lowest temperature STO films have a nearly amorphous layer w hich impacts their capacitance. Grain size increases with deposition t emperature, which correlates to higher dielectric constants. The latti ce parameter of the BST films is larger than that of bulk samples. Cap acitance, leakage, breakdown, and lifetime results are reported. (C) 1 997 American Institute of Physics.