Acoustic resonator and preparation method thereof

Abstract

The invention relates to an acoustic resonator and a preparation method thereof. The preparation method comprises the following steps of acquiring a support substrate; forming a single crystal thin film layer on the supporting substrate through an ion beam stripping and bonding method; epitaxially forming a high-sound-velocity layer on the single crystal thin film layer; forming a piezoelectric layer on the high sound velocity layer; forming a patterned electrode on the piezoelectric layer; wherein the sound velocity of the body wave propagated in the high sound velocity layer is greater thanthe sound velocity of the target elastic wave propagated in the piezoelectric layer. According to the preparation method, the high-sound-velocity layer is arranged below the piezoelectric layer, so the working frequency and the quality factor of the device can be effectively improved, the single crystal thin film layer which is expensive or cannot be directly obtained on the substrate in an epitaxial mode can be repeatedly transferred by utilizing an ion beam stripping and bonding technology, so preparation cost can be reduced, and meanwhile, the high-sound-velocity layer is deposited on the single crystal thin film layer by using an epitaxial technology to obtain the high-sound-velocity layer with the optimal thickness for constraining the sound wave energy, so the bandwidth and the quality factor of the sound wave resonator can be improved.

Description

technical field [0001] The present application relates to the field of semiconductor technology, in particular to an acoustic wave resonator and a preparation method thereof. Background technique [0002] Acoustic resonators are widely used in the field of communication as electronic components of acoustic filters. High-performance acoustic wave resonators can improve the quality of acoustic wave filters and broaden their application fields. [0003] In the era of high-speed communication, the operating frequency band of the acoustic wave filter is required to be higher and higher, and at the same time, a good bandwidth and quality factor (Q value) performance are required. However, the general working frequency of the surface acoustic wave (Surface Acoustic Wave, SAW) filter in the current acoustic wave filter is lower than 2 GHz. This is because the intrinsic target elastic wave sound velocity of the piezoelectric material of the acoustic resonator is not high; and altho...

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Problems solved by technology

[0004] The embodiment of the present application provides an acoustic wave resonator and its preparation method, which can solve the problem of low operating frequency of the surface acoustic wave filter, and the process is simple, the manufacturing cost is low, and it is conducive to large-scale production and use

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