Design of High-Q Film Bulk Acoustic Resonator for 5G Applications

This research represents the design of an optimized film bulk acoustic resonator (FBAR) with minimum spurious resonances which retains high-quality factor $(Q)$ and efficient electromechanical coupling $({k}_{eff}^{2})$ . Using the finite element method (FEM) simulation, we have developed the design with a three-step frame structure by parametric optimization. The membrane over an air gap device architecture is employed by the utilization of molybdenum for the top as well as the bottom electrode, aluminum nitride as a piezoelectric film, and silicon nitride as a support layer. The operating frequency of our designed resonator is 4.04 GHz, whereas the $Q_{s},Q_{p}$ and $\check{k}_{eff}^{2}$ are 8197, 3981, and 5.81%,respectively. The equivalent electrical modified Butterworth-Van Dyke (mBVD) model of the FBAR based on admittance response is also presented. Paving the way towards its final application in the high-frequency communication system