PHASE EVOLUTION AND ANNEALING EFFECTS ON THE ELECTRICAL-PROPERTIES OFPB(ZR0.53TI0.47)O-3 THIN-FILMS WITH RUO2 ELECTRODES

The electrical properties and crystallization of Pb(Zr0.53Ti0.47)O-3 ( PZT) thin films grown on RuO2 electrodes by the sol-gel process have b een studied. It was found that the amorphous as-deposited thin film fi rst transforms to a pyrochlore phase at 500 degrees C. On further anne aling, perovskite PZT begins to crystallize at about 600 degrees C. TE M anlysis reveals that a pyrochlore-type second phase still exists in the films even after annealing to temperatures of 750 degrees C for 10 min. These PZT films are fatigue-free, but they show large property v ariation and high leakage currents (J = 10(-3) A cm(-2) at 1 V). An 80 0 degrees C annealing treatment, for 10 min in air, of the RuO2 bottom electrode prior to film deposition enhanced perovskite PZT nucleation , thereby eliminating the pyrochlore-type second phase. In addition, t he leakage currents of PZT films grown on annealed RuO, electrodes are about two orders of magnitude lower than those of PZT films grown on unannealed RuO2. It is also observed that annealing the entire capacit or stack after the top electrode deposition improved capacitor propert ies.