A novel method for fabricating 2-D array piezoelectric micromachined ultrasonic transducers for medical imaging

Piezoelectric micromachined ultrasonic transducer (pMUT) is a new approach for the construction of 2-D arrays for real-time 3-D medical imaging. In this work, 6×6 pMUT arrays with element pitch down to 150µm were successfully fabricated and characterized. The devices consist of 2µm PZT film on a 3µm Si/SiO2 supporting layer, and the multilayered membrane was released by a two-step process to ensure high elements density. The resonance frequency and dielectric properties were also investigated and the results show its potential for the application in 3-D imaging probes.