Resonator and preparation method thereof

Abstract

The invention provides a resonator and a preparation method thereof. The resonator comprises a silicon substrate, a bottom electrode stacked on part of the silicon substrate, a piezoelectric layer covering the bottom electrode and part of the silicon substrate, and a top electrode and a Bragg reflection ring stacked on the piezoelectric layer. The Bragg reflection ring is arranged on the face, connected with the top electrode, of the piezoelectric layer, the Bragg reflection ring is arranged around the top electrode, the Bragg reflection ring comprises Bragg high-resistance layers and Bragg low-resistance layers which are alternately arranged in the radial direction of the Bragg reflection ring, and the acoustic impedance of the Bragg high-resistance layers is larger than that of the Bragglow-resistance layers. The Bragg high-resistance layer and the Bragg low-resistance layer have different acoustic impedances. The Bragg reflection ring with high acoustic impedance and low acoustic impedance can generate a plurality of reflection surfaces, transversely-propagated clutters can be partially reflected on the reflection surfaces, and the reflected clutters cancel each other out, so that a parasitic mode on a working interval is inhibited, a frequency response curve of the resonator is improved, filtering is reduced, and the overall performance of the resonator is improved.

Description

【Technical field】 [0001] The invention relates to the technical field of resonators, in particular to a resonator and a preparation method thereof. 【Background technique】 [0002] A resonator refers to an electronic component that generates a resonant frequency. Commonly divided into quartz crystal resonators and ceramic resonators. The function of the frequency generated by the resonator has the characteristics of stability and good anti-interference performance, and it is widely used in various electronic products. [0003] With the development of technology, quartz crystal resonators and ceramic resonators are no longer suitable for high-frequency and miniaturized products due to defects such as large volume and low frequency. The film bulk acoustic resonator manufactured by using the longitudinal wave resonance excited by the piezoelectric film material in its thickness direction has high frequency band, low power consumption, low temperature drift, low insertion loss, ...

AI Technical Summary

Problems solved by technology

like image 3 and Figure 4 As shown in the figure, the sound waves propagating laterally will be reflected when they propagate to the edge of the top electrode, and some clutter resonance points will be generated in the impedance curve of the resonator, especially in the working frequency band between the two resonant peaks, forming spurious modes and causing work The phase fluctuation in the frequency band affects the performance of the resonator, which in turn increases the ripple in the filter band

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