Thin-Film Bulk Acoustic Resonators Having Reduced Susceptibility to Process-Induced Material Thickness Variations

摘要

Thin-film bulk acoustic resonators include a resonator body (e.g., silicon body), a bottom electrode on the resonator body and a piezoelectric layer on the bottom electrode. At least one top electrode is also provided on the piezoelectric layer. In order to inhibit process-induced variations in material layer thicknesses from significantly affecting a desired resonant frequency of the resonator, the top and bottom electrodes are fabricated to have a combined thickness that is proportional to a target thickness of the piezoelectric layer extending between the top and bottom electrodes.