Bulk acoustic wave resonator, method for manufacturing bulk acoustic wave resonator, bulk acoustic wave resonator unit, filter, and electronic device

Abstract

The present invention relates to a single crystal thin film bulk acoustic resonator, comprising: a substrate; an acoustic mirror; a bottom electrode, connected with the bottom electrode pin; a top electrode, connected with the top electrode pin; a piezoelectric layer, arranged between the bottom electrode and the top electrode, wherein the piezoelectric layer is a single crystal film piezoelectriclayer, and an overlapping region of the acoustic mirror, the bottom electrode, the top electrode and the single crystal film piezoelectric layer in the thickness direction of the resonator forms an effective region of the resonator. The projections of the non-pin end of the top electrode and the non-pin end of the bottom electrode in the thickness direction of the resonator can be spaced apart from the edge of the acoustic mirror. The invention further relates to a manufacturing method of the single-crystal film bulk acoustic resonator, a single-crystal film bulk acoustic resonator unit withthe single-crystal film resonator 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 with the resonator, a bulk acoustic wave resonator unit, and an electronic device with the resonator or the filter . Background technique [0002] With the increasing development of 5G communication technology, the requirements for communication frequency bands are getting higher and higher. Due to the limitation of structure and performance, traditional radio frequency filters cannot meet the requirements of high frequency communication. Film Bulk Acoustic Resonator (FBAR), as a new type of MEMS device, is well adapted to the upgrading of wireless communication systems, making FBAR technology one of the research hotspots in the field of communication. Compared with traditional bulk acoustic resonators, FBAR thin film bulk acoustic resonators, which have the advantages of small size, light weight, low insertion los...

AI Technical Summary

Problems solved by technology

[0004] At present, most of the piezoelectric thin film materials used in traditional thin film bulk acoustic resonators are polycrystalline nitride thin films prepared by physical or chemical deposition techniques such as magnetron sputtering, and the piezoelectric properties are poor (mainly reflected in the low electromechanical coupling coefficient of the resonator. ), the defect density is high (mainly reflected in the low quality factor of the resonator), the heat dissipation is not good (mainly reflected in the low power capacity of the resonator), and there are etched oblique end faces at both ends of the bottom electrode of the resonator as shown in the figure As shown in 06 in 1, since the surface is generally rough, the defects in the piezoelectric layer deposited on the inclined end faces of the bottom electrode as shown in the region d in Figure 1 will be further enlarged

The existence of these defects will lead to acoustic loss, which will reduce the Q factor of the resonator, and cannot meet the technical indicators such as lower insertion loss and higher bandwidth required by future mobile communication technology.

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