Hybrid acoustic wave resonator of bulk acoustic wave resonator and surface acoustic wave resonator

Abstract

The invention provides a hybrid acoustic wave resonator of a bulk acoustic wave resonator and a surface acoustic wave resonator, which comprises a base, a bottom electrode, a piezoelectric layer and atop electrode which are sequentially arranged from bottom to top; a first reflecting layer is formed between the substrate and the bottom electrode so as to form a bulk acoustic wave resonator; an interdigital electrode is formed on the same piezoelectric layer; and a second reflection layer is formed between the substrate and the piezoelectric layer so as to form a surface acoustic wave resonator. According to hybrid acoustic wave resonator in the invention, through an integration process, the top electrode of the bulk acoustic wave resonator and the interdigital electrode of the surface acoustic wave resonator are directly formed on the same piezoelectric layer; the process flow is reduced; the phenomenon that the piezoelectric substrate is broken or severely warped in the original process is avoided; meanwhile, the parameters of the surface acoustic wave resonator can be adjusted so that the effects of restraining the transverse parasitic mode of the bulk acoustic wave resonator and inhibiting sound wave frequency doubling are achieved.

Description

technical field [0001] The invention belongs to the field of resonators, in particular to a hybrid acoustic wave resonator of a bulk acoustic wave resonator and a surface acoustic wave resonator. Background technique [0002] With the evolution of the communication frequency band, the required frequency is getting higher and higher. Under the high frequency requirement, the resonator needs to provide a better Q value to reduce the loss of the filter and obtain a higher quality filter response. . [0003] There are many ways to suppress lateral parasitic modes. The traditional process of integrating thin-film bulk acoustic wave resonators (BAW for short) and surface acoustic wave resonators (SAW for short) uses the acoustic wave substrate as the piezoelectric layer of the BAW device and integrates the SAW device. On the same substrate, but often due to the high temperature environment in the process, the piezoelectric substrate (for example: LiTaO 3 ) cracks or severe warpi...

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Problems solved by technology

[0003] There are many ways to suppress lateral parasitic modes. The traditional process of integrating thin-film bulk acoustic wave resonators (BAW for short) and surface acoustic wave resonators (SAW for short) uses the acoustic wave substrate as the piezoelectric layer of the BAW device and integrates the SAW device. On the same substrate, but often due to the high temperature environment in the process, the piezoelectric substrate (for example: LiTaO 3 ) cracking or severe warping

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