Preparation of Pb(Zr0.53Ti0.47)O3 Thick Films by an Interfacial Polymerization Method on Silicon Substrates and Their Electric and Piezoelectric Properties

Pb(Zr0.53Ti0.47)O3 (PZT) films of 10 to 50 µm in thickness were prepared by a new sol-gel process using an interfacial polymerization technique. The interfacial polymerization process is that an alkoxide precursor solution is poured on the surface of water in a container to form a gel film at the interface between the two immiscible liquids. The precursor solution was prepared by adding PZT alkoxide solution, PZT powders coated with Pb5Ge3O11 (PG), and a surfactant into hexane solvent. After the polymerization at the interface, the gel films were gently placed on a silicon substrate by draining the water in the container. The gel films containing PZT powders were sintered at 950°C for 10 min to obtain crystallized PZT films. The remanent polarization of a PZT thick film was 33.1 µC/cm2. The piezoelectric d 33 constant measured with a Mach-Zehnder interferometer was 225 pm/V and was independent of frequency from 0.2 to 3 kHz. A process to create patterns of PZT thick films was developed. The resonance frequencies of four square patterns of 2×2 mm2 in size were consistent, which indicated that the interfacial polymerization process enables the fabrication of uniform thick films in a large area.