High-frequency piezoelectric PZT film micromachined ultrasonic arrays

This paper presents the latest development of high-frequency PZT film ultrasonic linear arrays. A PZT thick film of 22 mum in thickness was fabricated with a spin-coating method. The film was found to have a remnant polarization of 30 muC/cm
²
and a coercive field Ec of 70 KV/cm. A high-frequency linear array was successfully fabricated with the film. The array shows a center frequency of 80 MHz and a bandwidth (-6 dB) of 80% with a layer of parylene as the matching. Measured results also show that the array has an insertion loss of -41 dB and a cross-talk of -25 dB at the center frequency.