The fabrication and characterization of PZT thin film Acoustic Devices for application in underwater robotic systems

Abstract

A high frequency spectrum lead zirconate titanate (PZT) thin film acoustic device was fabricated and studied for application using an underwater technique. The radio frequency (RF) planar magnetron sputtering method was used to deposit PZT thin film. The deposited PZT thin film IC (integrated circuits) fabrication processes were used to fabricate the acoustic devices. The optimized annealing conditions were 650°C and 20 min for PZT thin film deposited at 350°C for 2 h. The obtained PZT thin film had a dielectric constant of 869, a free dielectric constant ε(T)33 of about 893, a dielectric loss of 0.3, a concorcive electric field of 0.061 KV/cm, a piezoelectric constant d33 of 2.03 pm/V, a piezoelectric constant g33 = d33/ε(T)33 of 2.57 X 10-4 vm/N and a polarization level of 112.5 nC/cm. The fabricated PZT thin film acoustic devices can be used as transmitters on receivers. The highest levels of transmission sensitivity and receiving sensitivity, which can be obtained, are 76 dB and -75 dB, respectively. The acoustic device has better performance when poled PZT thin film is used.