Resonator and preparation method thereof

A resonator and Bragg reflection technology, applied in the field of resonators, can solve problems such as phase fluctuations, increase in filter band ripple, and affect resonator performance, so as to achieve the effects of reducing filtering, improving overall performance, and improving frequency response curves

CN110324022AActive Publication Date: 2019-10-11AAC TECH PTE LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2019-10-11

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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.
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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, ...

Examples

Embodiment Construction

[0039] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0040] Such as Figure 5 As shown, an embodiment of the present invention provides a resonator, including a silicon substrate 1, a bottom electrode 3 stacked on part of the silicon substrate 1, a piezoelectric layer 4 covering the bottom electrode 3 and part of the silicon substrate 1, The top electrode 5 and the Bragg reflection ring 6 stacked on the piezoelectric layer 4 .

[0041] The material of the piezoelectric layer 4 is aluminum nitride, which is an excellent piezoelectric material because of its high temperature resistance, stable chemical properties and good insulation performance. Moreover, the aluminum nitride film has a large electromechanical coupling coefficient, a high sound velocity, and good high-frequency performance, and is suitable for making surface acoustic wave devices.

[0042] The Bragg reflection ring 6 is disposed on the si...