Title:
BULK ACOUSTIC RESONATOR WITH ROUGH SURFACE, FILTER, AND ELECTRONIC DEVICE
Document Type and Number:
WIPO Patent Application WO/2020/098487
Kind Code:
A1
Abstract:
A bulk acoustic resonator, a filter comprising the resonator, and an electronic device comprising the filter The bulk acoustic resonator comprises: substrates (101, 201, 301, 401); acoustic mirrors (103, 203, 303, 403); bottom electrodes (105, 205, 305, 405) provided above the substrates (101, 201, 301, 401); top electrodes (109, 209, 309, 409) arranged opposite the bottom electrodes (105, 205, 305, 405); and piezoelectric layers (107, 207, 307, 407) provided above the bottom electrodes (105, 205, 305, 405) and between the bottom electrodes (105, 205, 305, 405) and the top electrodes (109, 209, 309, 409). The region where the acoustic mirrors (103, 203, 303, 403), the bottom electrodes (105, 205, 305, 405), the piezoelectric layers (107, 207, 307, 407), and the top electrodes (109, 209, 309, 409) are overlapped in the thickness direction of the substrates (101, 201, 301, 401) is an effective region (d2) of the resonator. The resonator is close to the border of the effective region (d2), and air gaps (113, 118, 214, 315, 317) are provided outside the border. At least one of surfaces corresponding to the air gaps (113, 118, 214, 315, 317) is a rough surface. The roughness of the rough surface is greater than that of the surface around the rough surface of the part where the rough surface is located. Rear-earth elements are doped in the piezoelectric layers.
Inventors:
ZHANG MENGLUN (CN)
PANG WEI (CN)
LIU BOHUA (CN)
YANG QINGRUI (CN)
PANG WEI (CN)
LIU BOHUA (CN)
YANG QINGRUI (CN)
Application Number:
PCT/CN2019/114035
Publication Date:
May 22, 2020
Filing Date:
October 29, 2019
Export Citation:
Assignee:
UNIV TIANJIN (CN)
ROFS MICROSYSTEM TIANJIN CO LTD (CN)
ROFS MICROSYSTEM TIANJIN CO LTD (CN)
International Classes:
H03H9/17; H03H3/02; H03H9/54
Domestic Patent References:
| WO2011105313A1 | 2011-09-01 |
Foreign References:
| US20160352308A1 | 2016-12-01 | |||
| US20160352308A1 | 2016-12-01 | |||
| CN1794572A | 2006-06-28 | |||
| CN107733396A | 2018-02-23 | |||
| CN103281050A | 2013-09-04 |
Attorney, Agent or Firm:
BEIJING JINCHENG TONGDA & NEAL LAW FIRM (CN)
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