Preparation method of film bulk acoustic resonator with electrodes provided with double-ring and bridge-shaped structures

Abstract

The invention discloses a preparation method of a film bulk acoustic resonator with electrodes provided with double ring-shaped and bridge-shaped structures, and the method specifically comprises the following steps: sequentially depositing a stripping layer, a piezoelectric layer and a lower electrode on a substrate, and depositing an inner ring-shaped bulge, an outer ring-shaped bulge and a lower sacrificial layer wrapping the two bulges on the lower electrode, depositing a lower protection layer wrapping the lower sacrificial layer and a to-be-bonded layer II wrapping the lower protection layer on the piezoelectric layer; bonding the to-be-bonded layer I and the to-be-bonded layer II on the substrate, and removing the stripping layer and the substrate; depositing two long-strip-shaped upper sacrificial layers on the piezoelectric layer, depositing two bridge-type structures on the two long-strip-shaped upper sacrificial layers, depositing an upper electrode with the two sides connected with the two bridge-type structures respectively on the surface of the piezoelectric layer, and depositing an upper protection layer on the upper electrode and the two bridge-type structures; and forming a through hole in the piezoelectric layer, and removing the strip-shaped upper sacrificial layer and the strip-shaped lower sacrificial layer. The surface of the lower electrode of the resonator is provided with the inner annular protrusion and the outer annular protrusion, and the two side walls of the upper electrode are each provided with a bridge-type structure, so that the film bulk acoustic wave resonator has a higher Q value.

Description

technical field [0001] The invention relates to a thin-film bulk acoustic wave resonator, in particular to a method for preparing a thin-film bulk acoustic wave resonator whose electrodes are provided with double ring and bridge structures. Background technique [0002] The electrode structure of the thin film bulk acoustic resonator has an important influence on the frequency and Q value of the thin film bulk acoustic resonator. The existing electrode structure design is often only carried out on the upper and lower surfaces of the electrode, and it has been difficult to further break through the thin film body with higher frequency and Q value. Acoustic resonator design. Moreover, most of the existing electrode structure designs are only carried out on the surface of the upper electrode, ignoring the influence of the lower electrode structure design on the frequency and Q value of the thin film bulk acoustic resonator. It can be seen that if the structural design of the u...

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Problems solved by technology

[0002] The electrode structure of the thin film bulk acoustic resonator has an important influence on the frequency and Q value of the thin film bulk acoustic resonator. The existing electrode structure design is often only carried out on the upper and lower surfaces of the electrode, and it has been difficult to further break through the thin film body with higher frequency and Q value. Acoustic Resonator Design

Moreover, most of the existing electrode structure designs are only carried out on the surface of the upper electrode, ignoring the influence of the lower electrode structure design on the frequency and Q value of the thin film bulk acoustic resonator

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