EFFECT OF ELECTRODE MICROSTRUCTURE ON LEAKAGE CURRENT IN LEAD-LANTHANUM-ZIRCONATE-TITANATE MULTILAYER CAPACITORS

Lead-lanthanum-zirconate-titanate (PLZT) multilayer capacitors involvi ng platinum bottom electrodes have been fabricated on a silicon nitrid e/silicon (SiN/Si) substrate system. Leakage current characteristics s how strong dependence on the processing temperature of the bottom elec trode. A drop in leakage current by five orders of magnitude has been observed for capacitor with platinum electrode deposited at room tempe rature. Scanning tunneling microscopy (STM) studies reveal significant differences in the microstructure of platinum films deposited at diff erent substrate temperatures. Based on STM results, a correlation betw een the microstructure of the bottom electrode, space layer at PLZT/Pt interface, and the nucleation of PLZT has been suggested to explain t his new observation. (C) 1996 American Institute of Physics.