Patent ID: 6407649
Filing Date: 2002-06-18
Classification: H03H,Y10T

Abstract:
A method of fabricating a monolithic bulk acoustic wave (BAW) 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, the method comprising the steps of:a) depositing and patterning bottom electrode material for use as the bottom electrode of each of the resonators of the duplexer; b) depositing and patterning piezoelectric material for use as the piezolayer of each of the resonators of the duplexer; c) depositing and patterning top electrode material for use as the top electrode of each of the resonators of the duplexer; d) providing a tuning layer for the shunt resonator of each of the two component duplexer filters; and e) providing a tuning layer for both the series and shunt resonators of one of the two component duplexer filters.