Novel In-Plane Polarized PZT Film Based Ultrasonic Micro-Acoustic Device
This paper presents the design, fabrication and testing results of a novel in-plane polarized PZT film based micro-acoustic device for ultrasonic applications. The proposed micro-acoustic device with Pt/PZT/TiO2/SiO2 structure can be used for both microphone and microspeaker due to the piezoelectric effect and converse piezoelectric effect of PZT film. The PZT film is polarized along in-plane direction by top square ring shaped interdigitated (IDT) electrodes and works in d33 mode. The fabricated d33-mode micro-acoustic devices have good ultrasonic receiving and transmitting performance, and the resonance frequency is around 44 kHz.