A STUDY OF SPUTTERED BARIUM STRONTIUM-TITANATE AND STRONTIUM-TITANATETHIN-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 120 fF/mu m(2) for BST films deposited at 600 degrees C and a high of 27 fF/mu m(2) for STO films deposited at 450 degrees C. Leakag e current densities at 3.3 V for the most part varied from mid 10(-8) to mid 10(-6) amps/cm(2). All of the dielectrics are polycrystalline, although the lowest temperature STO films have a nearly amorphous laye r which impacts their Grain size increases with deposition temperature , which correlates to higher dielectric constants. The lattice paramet er of the BST films is larger than that of bulk samples. Capacitance, leakage, breakdown, and lifetime results are reported.