Patent ID: 8720023
Filing Date: 2014-05-13
Classification: H03H,Y10T

Abstract:
1. A method of fabricating a monolithic duplexer comprising: depositing an insulation layer on an upper surface of a substrate; depositing and patterning a lower electrode on an upper surface of the insulation layer, so as to expose a first part of the insulation layer; depositing a piezoelectric layer on an upper surface of the exposed insulation layer and the lower electrode; depositing a metal on the upper part of the piezoelectric layer and patterning the metal to form an upper electrode and a metal layer, wherein the upper electrode forms a resonance part together with the lower electrode and the piezoelectric layer, the metal layer forms a trimming inductor, and the lower electrode electrically couples the resonance part and the trimming inductor; fabricating air gap type FBARs (film bulk acoustic resonances) by forming a cavity by etching the substrate under the resonance part; and bonding a packaging substrate on the substrate, the packaging substrate having a phase shifting part which substantially prevents inflow of signal between the air gap type FBARs.