Piezoelectric Properties and Acoustic Wave Detection of Pb(Zr0.52Ti0.48)O₃ Thin Films for Microelectromechanical Systems Sensor

Ferroelectric Pb(Zr 0.52 Ti 0.48 )O 3 thin films were deposited on Pt/TiO 2 /SiO 2 /Si substrates by the sol-gel technique. It was found that above 550°C the film transforms completely to the perovskite and forms a typical ferroelectric polarization-electric field (P-E) hysteresis loop. The effective d 33 of piezoelectric PZT films was measured using a Michelson interferometer. The piezoelectric hysteresis loop was measured according to dc bias voltage and the maximum piezoelectric coefficient for the 0.48-µm-thick poled film was about 130 pm/V at -3 V. Acoustic emission (AE) wave propagation through PZT films connected to a charge amplifier was observed. These properties suggested that PZT film is a very promising material for integrated AE sensor applications, with promise for improved reliability.