ELECTRICAL-PROPERTIES OF PB(ZR0.53TI0.47)O-3 THIN-FILM CAPACITORS WITH MODIFIED RUO2 BOTTOM ELECTRODES

Growth of Pb(Zr0.53Ti0.47)O-3 (PZT) thin films on RuO2 electrodes by t he sol-gel process is usually accompanied by the formation of second p hases. The resulting RuO2/PZT/RuO2 capacitors are fatigue-free up to n early 10(11) switching cycles, but they have high leakage currents (J similar to 10(-3) A/cm(2) at 1 volt) and large property variation. We have developed several modifications of the RuO2 bottom electrode whic h enhance nucleation of the perovskite phase, eliminate or reduce the second phases, and control film orientation and properties. The PZT fi lms deposited on the modified RuO2 electrodes have leakage current den sities which are two to four orders of magnitude lower than those of P ZT films deposited on the unmodified RuO2 electrodes. In most cases, t he excellent resistance to polarization fatigue which is characteristi c of the RuO2/PZT/RuO2 capacitors, is maintained.