DEGRADATION-FREE FERROELECTRIC PB(ZR,TI)O-3 THIN-FILM CAPACITORS WITHIRO2 TOP ELECTRODE

Degradation of ferroelectricity in PZT (Pb(Zr-0.52,Ti-0.48)O-3) thin-f ilm capacitors caused by heat treatment in a reductive ambience is inv estigated. We have found that the degradation of ferroelectricity depe nds upon the metal used for the top electrode of the PZT capacitor. Th e increased degradation in the case of a PZT capacitor with Pt electro des can be explained by a catalytic reaction on the Pt surface. With t he use of an IrO2 non-catalytic top electrode, we have made the ferroe lectricity of an IrO2/PZT/Pt capacitor retained even after the H-2 ann ealing at 400 degrees C, or above. This IrO2/PZT/Pt capacitor is a use ful structure to avoid H-2 damage in actual LSI fabrication processes.