Structure-Size Optimization and Fabrication of 3.7 GHz Film Bulk Acoustic Resonator Based on AlN Thin Film

Abstract

Traditional radio frequency filters cannot meet the demands of miniaturization, high frequency operation, integration, and broadband capacity in new-generation communication system owing to their larger volumes. A thin film bulk acoustic resonator (FBAR) is therefore suggested as an optimum solution because of its small volume and a good performance. In this study, the COMSOL multiphysics software was used to build 2 D and 3 D finite element models to analyze the harmonic characteristics of the FBAR. Based on the optimized structural parameters, the FBAR was fabricated with series resonant frequency, parallel resonant frequency, and effective coupling coefficient values of 3.705, and 3.82 GHz, and 7.4%, respectively. Compared with the simulated FBAR results, the effective coupling coefficient of the fabricated FBAR declined by only 0.1%, almost achieving the desired performance.

A review of piezoelectric MEMS sensors and actuators for gas detection application

“…Therefore, there is a new horizon that appears for FBAR in the high-frequency application. Additionally, there are some scholars extensively investigating the capability of the FBAR for several applications such as communication filters [314][315][316][317][318] and chemical detection [257,[319][320][321]. In addition, the researchers are still investigating the FBAR parameters for enhancing the device performance such as the quality factor, coupling coefficient, electromechanical coupling, device geometry, and the figure of merit [261,268,288,[322][323][324][325][326].…”