Electrical properties of lead zirconate titanate thin films deposited on lanthanum nickel cobaltate

Abstract

We investigated metallic lanthanum nickel cobaltate (LaNi0.6Co0.4O3, LNCO) thin films, which could replace noble metal electrodes in ferroelectric random access memories (FRAM). The LaNi0.6Co0.4O3 films were grown on silicon wafers (SiO2/Si) and on platinized silicon wafers (Pt/Ti/SiO2/Si) by using d.c. reactive sputtering method and were annealed in an oxygen atmosphere at 650 degrees C for 30 min. Pb(Zr0.48Ti0.52)O-3 (PZT) films deposited on LNCO/SiO2/Si and LNCO/Pt/Ti/SiO2/Si substrates had (100)-preferred and random orientations, respectively. The positive remanent polarization of the PZT films on the LNCO/SiO2/Si and the LNCO/Pt/Ti/SiO2/Si substrates were 16 mu C/cm(2) and 17 mu C/cm(2), respectively. The fatigue behaviors of the PZT films on the two types of LNCO bottom electrodes were better than that of the PZT films on a Pt bottom electrode.