Monolithic FBAR duplexer and method of making the same

Abstract

A monolithic bulk acoustic wave (BAW) duplexer, and a method for fabricating same, the duplexer having a, transmitter section as a first component filter and a receiver section as a second component filter, both component filters fabricated on a single substrate and both including at least one shunt BAW resonator and one series BAW resonator, each BAW resonator including a resonator section atop an isolation structure provided so as to separate the resonator section from the substrate, including: a patterned bottom electrode material for use as the bottom electrode of each of the resonators of the duplexer; a patterned piezoelectric material for use as the piezolayer of each of the resonators of the duplexer; a patterned top electrode material for use as the top electrode of each of the resonators of the duplexer; a tuning layer for the shunt resonator of each of the two component duplexer filters; and a tuning layer for both the series and shunt resonators of one of the two component duplexer filters. In some applications, each isolation structure is an acoustic mirror. Also in some applications, the duplexer further includes at least one planar spiral inductor provided in the course of depositing one or another layer of material in building up the duplexer, the planar spiral inductor having coils spiraling outward substantially in a plane from an innermost coil to an outermost coil.

Dependencies are inferred from the claim text.