Title:
NOVEL FBAR FILTER AND PREPARATION METHOD THEREFOR
Document Type and Number:
WIPO Patent Application WO/2022/134860
Kind Code:
A1
Abstract:
Disclosed are a novel FBAR filter and a preparation method therefor. The method comprises: etching a groove in a preparation substrate; preparing a piezoelectric material and a bottom electrode in the groove, and first preparing a thin seed layer before the bottom electrode is prepared; preparing an air cavity supporting layer; taking a supporting substrate, and bonding the supporting substrate to the preparation substrate and the air cavity supporting layer; removing the preparation substrate, and exposing the piezoelectric material; preparing a top electrode on the piezoelectric material, and leading out the bottom electrode to obtain a filter formed by cascading a plurality of resonators. According to the present invention, by means of the method of forming the groove in the preparation substrate and then growing the piezoelectric material, the problem of cracks caused by excessive stress due to growth of the whole piezoelectric film layer is effectively avoided, and the stress of the piezoelectric film is reduced; moreover, the problem of energy loss caused by transverse transmission of energy is effectively avoided due to discontinuity of the piezoelectric film of each resonance unit; furthermore, clutters can also be effectively suppressed, and the preparation yield and performance of the filter are improved.
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Inventors:
LI GUOQIANG (CN)
YI XINYAN (CN)
ZHAO LISHUAI (CN)
OUYANG PEIDONG (CN)
LIU HONGBIN (CN)
ZHANG TIELIN (CN)
YI XINYAN (CN)
ZHAO LISHUAI (CN)
OUYANG PEIDONG (CN)
LIU HONGBIN (CN)
ZHANG TIELIN (CN)
Application Number:
PCT/CN2021/127793
Publication Date:
June 30, 2022
Filing Date:
October 31, 2021
Export Citation:
Assignee:
UNIV SOUTH CHINA TECH (CN)
International Classes:
H03H9/17; H03H9/54
Domestic Patent References:
| WO2020040376A1 | 2020-02-27 |
Foreign References:
| CN112671367A | 2021-04-16 | |||
| CN109309483A | 2019-02-05 | |||
| CN110474616A | 2019-11-19 | |||
| CN103916100A | 2014-07-09 | |||
| CN107947750A | 2018-04-20 |
Attorney, Agent or Firm:
YOGO PATENT & TRADEMARK AGENCY LIMITED COMPANY (CN)
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