Development of Fabrication Processes for Stepper-Based AlN Acoustic Resonators

Speaker：Yuhan Tang

Location:  SIST 2-215

Time：     20th July. 2026 15:30

Host:         Prof. Tao Wu

Abstract:

Aluminum Nitride (AlN)-based bulk acoustic wave resonators serve as core components in radio frequency (RF) front-ends for 5G/6G communications. Their performance enhancement faces two critical challenges: the intrinsically limited electromechanical coupling coefficient of piezoelectric materials, and the demand for nanoscale patterning of interdigital transducer (IDT) features to achieve higher frequencies. Addressing these challenges, this thesis systematically investigates scandium-doped aluminum nitride (AlScN) thin film materials and stepper-based nanoscale patterning processes, aiming to establish a high-precision fabrication platform for high-frequency acoustic resonators. This work integrates two complementary research directions: the development of AlScN piezoelectric thin films with controlled doping and stress properties, and the establishment of a stepper-based nanolithography platform for high-precision IDT patterning. Key fabrication modules, including etching and release processes, are systematically developed to enable complete device integration. The overall goal is to build a scalable and reliable process platform that bridges material engineering with device fabrication for high-frequency piezoelectric resonators.

Biography:

Yuhan Tang received his bachelor's degree in Materials Science and Engineering from Wuhan University of Technology in Wuhan in 2023. He is currently pursuing a master's degree at ShanghaiTech University in Shanghai, where his research primarily focuses on the process development of stepper-based acoustic resonators.