Improved methods of forming PZT thin films that are compatible with industry-standard chemical vapor deposition production techniques are described. These methods enable PZT thin films having thicknesses of 70 nm or less to be fabricated with high within-wafer uniformity, high throughput and at a relatively low deposition temperature. In one aspect, a source reagent solution comprising a mixture of a lead precursor, a titanium precursor and a zirconium precursor in a solvent medium is provided. The source reagent solution is vaporized to form a precursor vapor. The precursor vapor is introduced into a chemical vapor deposition chamber containing the substrate. In another aspect, before deposition, the substrate is preheated during a preheating period. After the preheating period, the substrate is disposed on a heated susceptor during a heating period, after which a PZT film is formed on the heated substrate.
An actuator 1 in which a displacement element 7 has a piezoelectric ceramic layer 4 and a pair of electrodes 5, 6 interposing therebetween the piezoelectric ceramic layer 4. The entire thickness of the actuator 1 is 100 .mu.m or less. The piezoelectric ceramic layer 4 and the substrate 2 have as their principal component a perovskite crystal containing at least Pb; Zr and Ti, and, the maximum difference in a composition ratio Pb/(Ti+Zr) between the surface of the piezoelectric ceramic layer 4 and the inside of the substrate 2 is 0.02 or less. This reduces characteristic variation.
A ferroelectric memory device includes a lower interlayer dielectric on a semiconductor substrate, a plurality of ferroelectric capacitors, and a plate line. The ferroelectric capacitors are on the lower interlayer dielectric. The plate line extends across and electrically connects to surfaces of at least two adjacent ones of the plurality of ferroelectric capacitors.