11F-5 High-Frequency Piezoelectric PZT Film Micromachined Ultrasonic Transducers

This paper presents the latest development of MEMS high frequency ultrasound transducers with PZT piezoelectric thick films. Composite PZT solution was prepared and deposited on platinum-plated silicon wafers to fabricate active ferroelectrics thick-films. Particle size distribution (PSD) and powder of PZT-to-solution mass ratio effects of the composite solution were systematically studied to enhance electrical properties of PZT thick films. Improvements to the PZT film deposition process have yielded high quality, crack-free PZT films up to 18 mum in thickness. High-frequency (>80 MHz) transducers based on these thick PZT films have been successfully fabricated. The measured results show that these transducers possess much better sensitivity than previous PZT film transducers.