Films were deposited onto unheated, Ti/Pt coated Si substrates by reactive sputtering in an argon-oxygen atmosphere from a sintered PZT target, and subsequently crystallized at temperatures between 550 and 650 °C. Pt/PZT/Pt capacitors were formed by ion beam sputtering of top electrodes through a shadow mask. Electrical properties were found to depend on gas pressure during deposition. This effect is interpreted in terms of variations in film stoichiometry (particularly Pb content). Films with large excesses of Pb were found to exhibit high leakage currents and poor ferroelectric behavior, whereas films with lower excesses of Pb had low leakage currents, and good ferroelectric properties. Films with the largest Pb excess had a random orientation, while the film with the lowest Pb excess had a preferred (111) orientation. With 550 °C crystallization temperatures the films consist of a mixture of ferroelectric perovskite phase and either PZT pyrochlore or PbO. At higher crystallization temperatures no pyrochlore is detected.

The fatigue behavior of ferroelectric PZT capacitors with Ru and RuOx electrodes was studied. These capacitors show no sign of fatigue out to 1 X 1011 cycles, in sharp contrast to the degradation typically observed with Pt electrodes. Compared to Pt electrodes, the initial polarization was lower, but after fatiguing the polarization was comparable to or larger than that for Pt electrodes. Differences in polarization in response to switching and nonswitching pulses greater than 10 μC/cm2 were observed at 1 X 1011 cycles.

The effects of excess Pb and Zr/Ti ratio on crystallization behavior and ferroelectric properties of sol-gel derived films were studied. Excess Pb was found to reduce the crystallization temperature. Films with good ferroelectric properties (remanent polarization greater than 8 μC/cm2 ) were achieved after 550 °C, 5 minute crystallization. The difference in the magnitude of the charge in response to switching and non-switching pulses was greater than 1 μC/cm2 after 1011 fatigue cycles for many of the films. The arnount of charge remaining after fatigue was found to be dependent on the initial charge. Reducing the partial pressure of oxygen during crystallization affected both the remanent polarization and fatigue behavior. The fatigue rate was relatively independent of composition and crystallization temperature.