H2O vapor-induced leakage degradation of Pb(Zr,Ti)O3 thin-film capacitors with Pt and IrO2 electrodes

We have investigated the influence of H2O vapor on the leakage characteristics of Pb(Zr,Ti)O-3 (PZT) thin-film capacitors with Pt and IrO2 top electrodes by conducting electrical measurements ex situ in air and in situ in an 80% N-2/20% O-2 atmosphere with controlled humidity ranging from <0.1% to 95.5% relative humidity at 20degreesC. The results show that the leakage characteristics of PZT thin-film capacitors are strongly sensitive to H2O vapor in the atmosphere. The onset to H2O-induced leakage degradation depended on the relative humidity and on the quantity of charge passed through the capacitor. A degradation mechanism based on the electrolysis of H2O that has adsorbed on the capacitor from the atmosphere and the role of the electrode material in the degradation process are discussed. (C) 2002 American Institute of Physics.