Development of Mechanically-Robust Piezoelectric Micromachined Ultrasonic Transducer (pMUT) with Island-Shaped PZT Monocrystalline Thin Film

摘要

thin film (Mono-PZT). Mono-PZT has a high value of figure of merit (FOM) for pMUT. However, the mechanical fracture is often caused for a conventional-design pMUT during the resonant driving with a large displacement. That is perhaps due to its brittle property. For overcoming this problem, we proposed a new design: island-shaped Mono-PZT structure covered with a ring-shaped polyimide thin film. The fracture test proved that this design is effective for enhancing the mechanical robustness. This achievement has a great potential to create not only a higher-performance but also highly-reliable pMUT.