Bulk acoustic wave resonator having piezoelectric layer with insertion structure, filter, and electronic device

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; and a piezoelectric layer, wherein anoverlapped 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; a composite insertion structure arranged along the edge of the effective area is arranged in the piezoelectric layer; a composite insertion structure including a first insertion layer and a second insertion layer, at least a portion of the first insertion layer overlapping the active region in a plan view of the resonator, and at least a portion of the first insertion layer overlapping the second insertion layer in a plan view of the resonator; 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. 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

However, the above traditional composite structure or single-layer insertion structure has limited improvement on the energy leakage problem at the edge of the effective area of ​​the resonator, so the degree of improvement in Rp is also limited

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