Bulk acoustic wave resonator provided with insertion structure and temperature compensation layer, filter and electronic equipment

Abstract

The present invention relates to a bulk acoustic wave resonator, and the resonator comprises a substrate; an acoustic mirror; a bottom electrode; a top electrode; wherein an overlapped area of the acoustic mirror, the bottom electrode, the piezoelectric layer and the top electrode in the thickness direction of the substrate is an effective area of the resonator; wherein a composite insertion structure arranged along the edge of the effective region is arranged in the piezoelectric layer, the composite insertion structure comprises a first insertion layer and a second insertion layer, at leastone part of the first insertion layer is overlapped with the effective region in a top view of the resonator, and the first insertion layer is at least partially overlapped with the second insertion layer in the top view of the resonator, wherein the first insertion layer is made of a metal material and the second insertion layer is made of air or a dielectric material, or the first insertion layer is made of a dielectric material and the second insertion layer is made of air, in a top view of the resonator, at least one part of the temperature compensation layer is located in the effective area, and the temperature compensation layer is made of a material opposite to the piezoelectric layer in frequency temperature coefficient. The invention also relates to a filter and an electronic device.

Description

technical field [0001] Embodiments of the present invention relate to the field of semiconductors, and in particular to a bulk acoustic wave resonator, a filter, and an electronic device having one of the above components. Background technique [0002] Bulk acoustic wave filters have the advantages of low insertion loss, high square factor, and high power capacity. Therefore, they are widely used in contemporary wireless communication systems and are important components that determine the quality of radio frequency signals entering and leaving the communication system. The performance of a bulk acoustic wave filter is determined by the bulk acoustic wave resonator that constitutes it. For example, the resonant frequency of the bulk acoustic wave resonator determines the operating frequency of the filter, the effective electromechanical coupling coefficient determines the bandwidth of the filter, and the quality factor determines the filter insertion. loss. When the filter ...

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Problems solved by technology

[0004] However, as the operating temperature changes, figure 1 The resonant frequency of the shown resonator drifts, and this temperature drift limits the practical application of composite insertion resonators

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