Title:
BULK ACOUSTIC WAVE (BAW) DEVICE WITH OPPOSITELY POLARIZED PIEZOELECTRIC LAYERS FOR HIGHER ORDER RESONANCE AND METHOD OF MANUFACTURE
Document Type and Number:
WIPO Patent Application WO/2024/063697
Kind Code:
A3
Abstract:
A bulk acoustic wave, BAW, device comprises a layer stack (102) including first electrode (104A) and a second electrode (104B), a first piezoelectric layer (106A) between the electrodes, and a second piezoelectric layer (106B) between the first piezoelectric layer and the second electrode. A polarization (P2) of a crystal structure of the second piezoelectric layer is opposite to a polarization (Pl) of a crystal structure of the first piezoelectric layer to achieve higher order resonant frequencies in the BAW device by means other than merely thinning layers in the layer stack. In some examples, the BAW device is a two-terminal device and does not include a metal layer configured to be a third electrode. In some examples, the BAW device includes at least one intermediate layer (120, 122, 124) between the first and second piezoelectric layers, and a total combined thickness of the at least one intermediate layer is less than 4% of a total thickness of the layer stack.
Inventors:
SCHIEK MAXIMILIAN (SG)
AIGNER WILLI (SG)
CERANSKI CHRISTIAN (SG)
AIGNER WILLI (SG)
CERANSKI CHRISTIAN (SG)
Application Number:
PCT/SG2023/050627
Publication Date:
May 16, 2024
Filing Date:
September 15, 2023
Export Citation:
Assignee:
RF360 SINGAPORE PTE LTD (SG)
International Classes:
H03H3/02; H03H9/02; H03H9/17
Domestic Patent References:
| WO2021241696A1 | 2021-12-02 |
Foreign References:
| US20050012568A1 | 2005-01-20 | |||
| JP2007036915A | 2007-02-08 | |||
| US20180085787A1 | 2018-03-29 | |||
| US20210036678A1 | 2021-02-04 | |||
| US20140246305A1 | 2014-09-04 | |||
| US20130193808A1 | 2013-08-01 |
Other References:
KAWASAKI O. ET AL: "Variable property crystal resonators by direct bonding techniques", 1996 IEEE ULTRASONICS SYMPOSIUM. PROCEEDINGS, vol. 2, 1 January 1996 (1996-01-01), pages 897 - 900, XP093034250, DOI: 10.1109/ULTSYM.1996.584137
Attorney, Agent or Firm:
DREW & NAPIER LLC (SG)
Download PDF: