FABRICATION AND ELECTRICAL CHARACTERIZATION OF PT (BA,SR)TIO3/PT CAPACITORS FOR ULTRALARGE-SCALE INTEGRATED DYNAMIC RANDOM-ACCESS MEMORY APPLICATIONS/

Pt/(Ba,Sr)TiO3/Pt capacitors are fabricated using DC and RF magnetron sputtering processes on thermally oxidized silicon wafers for ultralar ge scale integrated dynamic random access memory (ULSI DRAM) applicati ons. (Ba,Sr)TiO3 (BST) thin film deposited at 640 degrees C to 20 nm t hickness shows an equivalent SiO2 thickness (t(oxeq)) of 0.35 nm and a leakage current density, measured at an applied voltage of 1.5 V, of about 100 nA/cm(2) . t(oxeq) of the BST film and leakage current densi ty are further decreased to 0.24 nm and 40 nA/cm(2), respectively, by postannealing at 750 degrees C after fabrication of the top electrode.