Title:
FLATTENING METHOD
Document Type and Number:
WIPO Patent Application WO/2021/212547
Kind Code:
A1
Abstract:
Provided is a flattening method, capable of improving a local flatness uniformity of a product to be processed. The product is provided with a cavity filled with an oxide, and comprises a first electrode layer, a piezoelectric layer, and a second electrode layer that are stacked on the cavity. The first electrode covers the cavity, and comprises a first inclined surface portion located at a periphery of the first electrode layer. The piezoelectric layer covers the first electrode layer, and forms a second inclined surface portion at a surface thereof. The second electrode layer covers a portion of the piezoelectric layer, and comprises a third inclined surface portion located at a periphery of the second electrode layer. The flattening method comprises: depositing a passivation layer on the second electrode layer, wherein the passivation layer covers the second electrode layer and the piezoelectric layer, and has a first flat surface portion, a fourth inclined surface portion provided around the first flat surface portion, and a second flat surface portion extending from the fourth inclined surface portion, a projection of the first flat surface portion in a vertical direction covers the cavity, and an orthographic projection of the fourth inclined surface portion in the vertical direction falls outside of the cavity; and performing full-surface etching on the passivation layer until a thickness of the passivation layer is reduced to a desired thickness.
Inventors:
LOO LI ENG (SG)
LAI KAH KEEN (SG)
WU YILEI (CN)
LAI KAH KEEN (SG)
WU YILEI (CN)
Application Number:
PCT/CN2020/088780
Publication Date:
October 28, 2021
Filing Date:
May 06, 2020
Export Citation:
Assignee:
AAC ACOUSTIC TECH SHENZHEN CO LTD (CN)
International Classes:
H03H9/17
Foreign References:
| CN1472884A | 2004-02-04 | |||
| CN110912528A | 2020-03-24 | |||
| CN111554800A | 2020-08-18 | |||
| US20080174389A1 | 2008-07-24 | |||
| US20190199319A1 | 2019-06-27 | |||
| CN105262456A | 2016-01-20 | |||
| CN110957413A | 2020-04-03 |
Attorney, Agent or Firm:
GUANGZHOU YUEXIU JILY PATENT & TRADEMARK LAW OFFICE (CN)
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