Key issues and challenges in device level fabrication of MEMS acoustic sensors using piezo thin films doped with strontium and lanthanum

The article delves into the intricate challenges faced during the fabrication of MEMS acoustic sensors using Sr and La co-doped PSLZT thin films. It begins by highlighting the necessity of high-performance acoustic sensors in underwater systems and the role of MEMS-based sensors in this context. The authors discuss the critical issues related to the selection, deposition, and patterning of bottom electrodes, particularly the challenges with Pt/TiOx electrodes. They also explore the problems associated with the preparation of sputtering targets, including target density, composition, and the formation of cracks. The article further examines the challenges in the sputtering process itself, such as the optimization of deposition parameters and the prevention of target failure. Additionally, it addresses the difficulties in patterning PSLZT thin films, including the undercutting issues during wet etching. The narrative offers valuable insights into the optimization strategies and solutions to overcome these fabrication challenges, making it a comprehensive resource for researchers and engineers in the field.