Title:
BULK ACOUSTIC WAVE FILTER AND MANUFACTURING METHOD THEREFOR
Document Type and Number:
WIPO Patent Application WO/2021/003699
Kind Code:
A1
Abstract:
A manufacturing method for a bulk acoustic wave filter, comprising: sequentially forming acoustic reflection air chambers (2), seed layers (3), lower electrode layers (4), and piezoelectric layers (5, 5-1, 5-2, 5-3) of n resonators (201-1, 201-2, 201-3) on a substrate (1), n being greater than or equal to 2; setting N as 1 to n in turn and separately repeating the following process: forming N-th metal hard mask layers (6-1, 6-2, 6-3), defining effective areas of the first resonator (201-1) to the N-th resonators (201-2, 201-3) by using a photoetching process, removing the N-th metal hard mask layers (6-1, 6-2, 6-3) outside the effective areas of the first resonator (201-1) to the N-th resonators (201-2, 201-3), performing oxidation treatment on the piezoelectric layers (5, 5-1, 5-2, 5-3) outside the effective areas of the first resonator (201-1) to the N-th resonators (201-2, 201-3) to form N-th piezoelectric layer oxidized portions, etching the N-th piezoelectric layer oxidized portions, and removing the metal hard mask layers (6-1, 6-2, 6-3) of the effective areas of the first resonator (201-1) to the N-th resonators (201-2, 201-3), so as to form the piezoelectric layers (5, 5-1, 5-2, 5-3) of the first resonator (201-1) to the N-th resonators (201-2, 201-3) having different thicknesses; and forming upper electrode layers (7) on the piezoelectric layers (5, 5-1, 5-2, 5-3) of the first resonator (201-1) to the N-th resonators (201-2, 201-3) having different thicknesses.
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Inventors:
WANG WEI (CN)
LI PING (CN)
HU NIANCHU (CN)
JIA BIN (CN)
LI PING (CN)
HU NIANCHU (CN)
JIA BIN (CN)
Application Number:
PCT/CN2019/095424
Publication Date:
January 14, 2021
Filing Date:
July 10, 2019
Export Citation:
Assignee:
EPICMEMS XIAMEN CO LTD (CN)
International Classes:
H03H9/58; H03H9/205; H03H9/54
Foreign References:
| US20020089395A1 | 2002-07-11 | |||
| CN208143193U | 2018-11-23 | |||
| CN107094004A | 2017-08-25 | |||
| US20080129412A1 | 2008-06-05 | |||
| US5920242A | 1999-07-06 |
Attorney, Agent or Firm:
CHINA SCIENCE PATENT & TRADEMARK AGENT LTD. (CN)
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