Preparation method of FBAR duplexer and FBAR duplexer

Abstract

The invention provides a preparation method of an FBAR duplexer and the FBAR duplexer. The preparation method comprises the steps of S101 etching a cavity at one side of the first substrate, and forming a first bonding layer at the same side of the first substrate; S102 forming a piezoelectric layer on one side of the second substrate, and forming a bottom electrode partially covering the piezoelectric layer on the side, away from the second substrate, of the piezoelectric layer; S103 forming a second bonding layer in mirror symmetry with the first bonding layer on the piezoelectric layer andthe bottom electrode, and etching the piezoelectric layer to form a first through hole; and S104 bonding and connecting the first bonding layer and the second bonding layer, etching the second substrate to form a second through hole, removing the second substrate, and forming a top electrode on one side, far away from the bottom electrode, of the piezoelectric layer. According to the invention, the first bonding layer and the second bonding layer are used as grounding, and simultaneously, the first bonding layer and the second bonding layer are patterned to obtain equivalent inductance and capacitance, so that the occupied area is prevented from being increased, the device integration is realized, the electrical performance can be directly detected after tape-out, and the manufacturing process is convenient to control.

Description

Technical field [0001] The invention relates to the technical field of thin film bulk acoustic wave resonators, in particular to a preparation method of an FBAR duplexer and an FBAR duplexer. Background technique [0002] The FBAR duplexer is composed of two FBAR (Film Bulk Acoustic Resonator) filters of different frequency bands. In the existing manufacturing process, in order to achieve the effect of different frequency bands, the method adopted is one After the seed film is completed, continue to grow another film on it, and finally superimpose to form the structure required for resonance. However, this method will cause the surface of the film to be chemically or physically treated, and the roughness will increase the risk. [0003] In addition, in order to be able to test the performance of the FBAR duplexer in the product process form during the tapeout process, it needs to be testable before packaging. However, there is still a problem. In the two filter design optimizatio...

AI Technical Summary

Problems solved by technology

However, there is still a problem. In the design optimization of the two filters, inductance and band content adjustment may be used. If the introduction of these devices still needs to be integrated, it needs to be obtained by an equivalent method.

Generally, the space on the wafer is limited, and if the area occupied by the equivalent inductor or capacitor is larger than that of the external components, it is difficult to achieve the purpose of device integration, and thus the performance test of the FBAR duplexer cannot be performed during the tape-out process.

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