Bulk acoustic wave resonator with electrode having gap layer and protruding 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 disposed between the bottom electrode and the top electrode, wherein an overlapping region of the top electrode, the bottom electrode, the acoustic mirror, and the piezoelectric layer in a thickness direction ofthe resonator defines an effective region of the resonator; the top electrode comprises a gap layer, a first top electrode and a second top electrode, wherein the gap layer is formed between the first top electrode and the second top electrode in the thickness direction of the resonator, and the first top electrode is in surface contact with the piezoelectric layer; the first top electrode is provided with a protruding structure at the edge of the effective area in the effective area, and the top surface of the protruding structure is higher than the upper surface of the first top electrode in the effective area. The invention further relates to a filter with the resonator and electronic equipment with the filter or the resonator.

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 with the resonator, and an electronic device with the resonator or the filter. Background technique [0002] As the basic elements of electronic equipment, electronic devices have been widely used, including mobile phones, automobiles, home appliances, etc. In addition, technologies such as artificial intelligence, the Internet of Things, and 5G communications that will change the world in the future still need to rely on electronic devices as the basis. [0003] Electronic devices can exert different characteristics and advantages according to different working principles. Among all electronic devices, devices that use the piezoelectric effect (or inverse piezoelectric effect) are one of the most important categories. Piezoelectric devices have a very wide range of application scenarios . Film Bulk Acoustic Resona...

AI Technical Summary

Problems solved by technology

For bulk acoustic wave resonators and filters, high operating frequency means that the film thickness, especially that of the electrode, needs to be further reduced; however, the main negative effect brought about by the reduction of the electrode film thickness is the resonator Q due to the increase in electrical loss. value decreases, especially the Q value at the series resonance point and its frequency vicinity; correspondingly, the performance of high operating frequency bulk acoustic wave filter is also greatly deteriorated with the decrease of the Q value of the bulk acoustic wave resonator

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