Novel flexible FBAR on PET substrate

A novel flexible Film Bulk Acoustic Wave Resonators (FBARs) based on ZnO/PET structure was fabricated without back-etch. The PET layer is applied as acoustic reflector and substrate of FBAR. It has 1.14GHz parallel resonant frequency, 1.229GHz series resonant frequency and about 150 Q factors. The FBARs acoustic impedance is improved by using harden metal Au instead of Al as the bottom electrodes. The ZnO/PET structure FBAR is also simulated by COSMOL to confirm its working mechanism.