Title:
METHOD FOR RAPIDLY FORMING CAVITY STRUCTURE OF MICRO-ACOUSTIC FILM RESONATOR
Document Type and Number:
WIPO Patent Application WO/2023/082521
Kind Code:
A1
Abstract:
The present invention belongs to the technical field of film bulk acoustic resonators. Disclosed is a method for rapidly forming a cavity structure of a micro-acoustic film resonator. The method comprises: etching a groove in a silicon substrate, forming a first sacrificial layer at the bottom of the groove, forming a second sacrificial layer on the first sacrificial layer and on an inner wall of the groove, forming a third sacrificial layer in the center of the second sacrificial layer, and then forming a supporting layer on the third sacrificial layer; and then, forming a bottom electrode on the supporting layer, removing the second sacrificial layer first by means of wet etching, then removing the first sacrificial layer and the third sacrificial layer, and finally forming a piezoelectric layer and a top electrode on the bottom electrode, so as to form a cavity structure of a micro-acoustic film resonator. The supporting layer cannot completely cover the second sacrificial layer. A specific structure having three sacrificial layers is designed, and the middle sacrificial layer is then removed first by using wet etching, such that the contact area between an etching liquid and each of the upper sacrificial layer and the lower sacrificial layer is increased, thereby achieving the aim of rapidly forming a cavity structure.
Inventors:
WU XIUSHAN (CN)
XU LIN (CN)
CUI JIAMIN (CN)
YAO WEI (CN)
PENG TAO (CN)
YAN SHUBIN (CN)
ZHU ZHENYU (CN)
XU LIN (CN)
CUI JIAMIN (CN)
YAO WEI (CN)
PENG TAO (CN)
YAN SHUBIN (CN)
ZHU ZHENYU (CN)
Application Number:
PCT/CN2022/082143
Publication Date:
May 19, 2023
Filing Date:
March 22, 2022
Export Citation:
Assignee:
UNIV ZHEJIANG WATER RESOURCES & ELECTRIC POWER (CN)
International Classes:
H03H3/02; H03H9/02
Foreign References:
| CN114050800A | 2022-02-15 | |||
| CN112563878A | 2021-03-26 | |||
| JP2005109678A | 2005-04-21 | |||
| CN108288960A | 2018-07-17 | |||
| CN109981069A | 2019-07-05 | |||
| CN110690871A | 2020-01-14 | |||
| US20070228880A1 | 2007-10-04 |
Other References:
JIAO, XIANGQUAN: "Reseach on Cavity Structure of Film Bulk Acoustic Resonator", CHINA DOCTORAL DISSERTATIONS FULL-TEXT DATABASE, INFORMATION SCIENCE AND TECHNOLOGY, no. 03, 15 March 2016 (2016-03-15), ISSN: 1674-022X
Attorney, Agent or Firm:
BEIJING ZHUOSHENG BAIDA IP AGENT LTD. (CN)
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