3D FEM Analysis of High-Frequency AlN-Based PMUT Arrays on Cavity SOI
Wenjuan Liu,
Leming He,
Xubo Wang,
Jia Zhou,
Weijiang Xu,
Nikolay Smagin,
Malika Toubal,
Hao Yu,
Yuandong Gu,
Jinghui Xu,
Denis Remiens,
Junyan Ren
Affiliations
Wenjuan Liu
State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 201203, China
Leming He
State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 201203, China
Xubo Wang
State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 201203, China
Jia Zhou
State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 201203, China
Weijiang Xu
Université Polytechnique Hauts-de-France, CNRS, Université Lille, ISEN. Centrale Lille, UMR 8520–IEMN—Institut d’Électronique de Microélectronique et de Nanotechnologie, DOAE—Département d’Opto-Acousto- Électronique, F-59313 Valenciennes CEDEX 9, France
Nikolay Smagin
Université Polytechnique Hauts-de-France, CNRS, Université Lille, ISEN. Centrale Lille, UMR 8520–IEMN—Institut d’Électronique de Microélectronique et de Nanotechnologie, DOAE—Département d’Opto-Acousto- Électronique, F-59313 Valenciennes CEDEX 9, France
Malika Toubal
Université Polytechnique Hauts-de-France, CNRS, Université Lille, ISEN. Centrale Lille, UMR 8520–IEMN—Institut d’Électronique de Microélectronique et de Nanotechnologie, DOAE—Département d’Opto-Acousto- Électronique, F-59313 Valenciennes CEDEX 9, France
Hao Yu
School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore
Yuandong Gu
Institute of Microelectronics, Agency for Science, Technology and Research (A*STAR), Singapore 138634, Singapore
Jinghui Xu
Institute of Microelectronics, Agency for Science, Technology and Research (A*STAR), Singapore 138634, Singapore
Denis Remiens
Université Polytechnique Hauts-de-France, CNRS, Université Lille, ISEN. Centrale Lille, UMR 8520–IEMN—Institut d’Électronique de Microélectronique et de Nanotechnologie, DOAE—Département d’Opto-Acousto- Électronique, F-59313 Valenciennes CEDEX 9, France
Junyan Ren
State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai 201203, China
This paper presents three-dimensional (3D) models of high-frequency piezoelectric micromachined ultrasonic transducers (PMUTs) based on the finite element method (FEM). These models are verified with fabricated aluminum nitride (AlN)-based PMUT arrays. The 3D numerical model consists of a sandwiched piezoelectric structure, a silicon passive layer, and a silicon substrate with a cavity. Two types of parameters are simulated with periodic boundary conditions: (1) the resonant frequencies and mode shapes of PMUT, and (2) the electrical impedance and acoustic field of PMUT loaded with air and water. The resonant frequencies and mode shapes of an electrically connected PMUT array are obtained with a laser Doppler vibrometer (LDV). The first resonant frequency difference between 3D FEM simulation and the measurement for a 16-MHz PMUT is reasonably within 6%, which is just one-third of that between the analytical method and the measurement. The electrical impedance of the PMUT array measured in air and water is consistent with the simulation results. The 3D model is suitable for predicting electrical and acoustic performance and, thus, optimizing the structure of high-frequency PMUTs. It also has good potential to analyze the transmission and reception performances of a PMUT array for future compact ultrasonic systems.
