Chpater 31: Electrical Properties of Pb(Zr[sub(0.53)]Ti[sub(0.47)] )O[sub(3)] Thin Film Capacitors with Modified Ru02 Bottom Electrrodes

Abstract Growth of Pb(Zro.5 3 Tio.4 7 ) 0 3 (PZT) thin films on Ru02 electrodes by the sol-gel process is usually accompanied by the formation of second phases. The resulting Ru02 /PZT/Ru02 capacitors are fatigue-free up to nearly 101 1 switching cycles, but they have high leakage currents (J~10 A/cm at 1 volt) and large property variation. We have developed several modifications of the Ru02 bottom electrode which enhance nucleation of the perovskite phase, eliminate or reduce the second phases, and control film orientation and properties. The PZT films deposited on the modified Ru02 electrodes have leakage current densities which are two to four orders of magnitude lower than those of PZT films deposited on the unmodified Ru02 electrodes. In most cases, the excellent resistance to polarization fatigue which is characteristic of the Ru02 /PZT/Ru02 capacitors, is maintained.