Design and Optimization of Piezoelectric MEMS Resonator Electrodes using Finite Element Methods and Image Processing

Abstract:
This work focuses on the design and optimization of piezoelectric microelectromechanical system (MEMS) resonator electrodes. A systematic workflow is implemented to design and model the optimal top aluminum nitride (AlN) electrodes corresponding to mode 5 of a 5 µm thick silicon membrane with a diameter of 1550 µm. The electrode outlines are based on the stress transition zones determined by modal analysis. The resulting optimal electrode has roughly a triangular form and an area of 0.31 mm². The harmonic analysis yields the frequency response for different electrode and the amplitude of optimized electrodes is 65.2% higher than the amplitude of the next-best electrode analyzed. The image processing workflow presented here facilitates the easy transfer of optimal electrode layouts onto a wafer for manufacturing.