High-frequency acoustic wave resonator and preparation method thereof

A high-frequency acoustic wave and resonator technology, applied in electrical components, impedance networks, etc., can solve the problems of low resonance frequency, low electromechanical coupling coefficient, and temperature drift of acoustic wave resonators, so as to improve temperature stability and reduce temperature. Drift and reduce the effect of leakage

CN111416590AActive Publication Date: 2020-07-14SHANGHAI INST OF MICROSYSTEM & INFORMATION TECH CHINESE ACAD OF SCI
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2020-07-14

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Abstract

The invention provides a high-frequency acoustic wave resonator and a preparation method thereof. The high-frequency acoustic wave resonator comprises a high-acoustic-velocity support substrate, an insulating dielectric layer which is located on the upper surface of the high-sound-velocity supporting substrate, a piezoelectric film which is located on the upper surface of the insulating dielectriclayer, and an interdigital electrode which is located on the upper surface of the piezoelectric film. By arranging the high-sound-velocity supporting substrate below the piezoelectric film, the soundvelocity of target elastic waves excited and propagated in the piezoelectric film can be increased, propagation of the target elastic waves can be effectively restrained, and the resonant frequency of the high-frequency sound wave resonator is improved; the insulating dielectric layer is arranged between the piezoelectric film and the high-sound-velocity supporting substrate, the leakage of electric field energy in the piezoelectric film can be effectively reduced, and the electromechanical coupling coefficient of the high-frequency sound wave resonator can be enhanced; by selecting the appropriate insulating dielectric layer, temperature compensation can be carried out on the high-frequency acoustic wave resonator, temperature drift of the high-frequency acoustic wave resonator is reduced, and temperature stability of the high-frequency acoustic wave resonator is improved.
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Description

technical field

[0001] The present application relates to the technical field of semiconductor preparation, in particular to a high-frequency acoustic wave resonator and a preparation method thereof. Background technique

[0002] With the development of Internet and 5G technology, the market demand for radio frequency devices continues to grow. Surface acoustic wave filters are widely used in RF front-ends, and their operating frequency is mainly determined by the period of the interdigital electrodes and the velocity of elastic waves excited in piezoelectric materials. The operating frequency of existing surface acoustic wave filters is generally lower than 3GHz, while the FR1 frequency band in 5G communication can reach up to 6GHz. Existing surface acoustic wave filters have problems such as low resonance frequency, low electromechanical coupling coefficient, and temperature drift. However, it cannot fully meet the needs of 5G communication. Although reducing the period ...

Examples

preparation example Construction

[0053] On the other hand, the embodiment of the present application discloses a method for preparing the above-mentioned high-frequency acoustic wave resonator, figure 2 It is a schematic flow chart of a method for preparing a high-frequency acoustic resonator according to an embodiment of the present application. The method includes the following steps:

[0054] S1: Obtain a high-sonic support substrate 1;

[0055] S2: Prepare and form an insulating dielectric layer 2 on the upper surface of the high-sonic support substrate 1; the formation method of the insulating dielectric layer includes a deposition method, an epitaxy method or a thermal oxidation method;

[0056] S3: Prepare and form the piezoelectric film 3 on the upper surface of the insulating medium layer 2; the forming method of the piezoelectric film 3 includes deposition method, epitaxy method, ion beam stripping method or bonding method.

[0057] S4: prepare and form the interdigital electrode 4 on the upper surf...

Embodiment 1

[0072] Embodiment 1 of the present application provides a high-frequency acoustic wave resonator on the one hand, including:

[0073] A high-sonic support substrate 1; the high-sonic support substrate 1 is a SiC substrate;

[0074] An insulating dielectric layer 2, the insulating dielectric layer 2 is located on the upper surface of the high-sonic supporting substrate 1; the insulating dielectric layer 2 is SiO 2 insulating dielectric layer;

[0075] Piezoelectric film 3, the piezoelectric film 3 is located on the upper surface of the insulating medium layer 2; the piezoelectric film 3 is LiNbO 3 single crystal thin film;

[0076] The interdigital electrodes 4 are located on the upper surface of the piezoelectric film 3 .

[0077] Embodiment 1 of the present application provides a method for preparing a high-frequency acoustic wave resonator on the other hand, comprising the following steps:

[0078] Obtain SiC high-sonic support substrate;

[0079] Preparation and format...