Title:
BULK ACOUSTIC RESONATOR AND MANUFACTURING METHOD THEREFOR, FILTER AND ELECTRONIC DEVICE
Document Type and Number:
WIPO Patent Application WO/2021/248866
Kind Code:
A1
Abstract:
A bulk acoustic resonator and a manufacturing method therefor, a filter and an electronic device. The manufacturing method comprises: providing a substrate (100), a groove (110) being formed in the substrate (100); forming a sacrificial layer (130) located in the groove (110); forming a bottom electrode (140) located on the sacrificial layer (130), part of the boundary of the bottom electrode (140) being located above the groove (110), and part thereof extending onto the substrate (100) on the periphery of the groove (110); forming a planarization layer (500) that is located on the substrate (100) exposed from the bottom electrode (140) and is in contact with the side wall of the bottom electrode (140), the top face of the planarization layer (500) being flush with the top face of the bottom electrode (140); forming a piezoelectric layer (170) that covers the bottom electrode (140) and the planarization layer (500); forming a top electrode (180) on the piezoelectric layer (170), a piezoelectric acoustic resonance lamination layer (550) comprising the bottom electrode (140), the piezoelectric layer (170) and the top electrode (180); forming release holes (190) penetrating through the piezoelectric acoustic resonance lamination layer (550); and removing the sacrificial layer (130) via the release holes (190), so as to form a cavity (200). The bottom electrode (140) and the planarization layer (500) are formed to provide a flat face for the formation of the piezoelectric layer (170), such that the piezoelectric layer (170) can be kept flat, thereby eliminating boundary standing waves and clutters, and thus improving the quality factor of the resonator.
Inventors:
HUANG HERB HE (CN)
Application Number:
PCT/CN2020/137219
Publication Date:
December 16, 2021
Filing Date:
December 17, 2020
Export Citation:
Assignee:
NINGBO SEMICONDUCTOR INT CORPORATION SHANGHAI BRANCH (CN)
International Classes:
H03H9/17; H03H3/02; H03H9/02
Foreign References:
| CN109714016A | 2019-05-03 | |||
| CN104883153A | 2015-09-02 | |||
| US20140111288A1 | 2014-04-24 | |||
| US20140159548A1 | 2014-06-12 | |||
| CN1864326A | 2006-11-15 |
Attorney, Agent or Firm:
INTEBRIGHT LLP (CN)
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