US 12,334,901 B2
Elastic wave element, ladder filter, demultiplexer, and communication apparatus
Toshiya Kimura, Kyotanabe (JP); and Shigeyuki Kikuchi, Omiyahata (JP)
Assigned to KYOCERA Corporation, Kyoto (JP)
Appl. No. 18/017,786
Filed by KYOCERA Corporation, Kyoto (JP)
PCT Filed Jul. 30, 2021, PCT No. PCT/JP2021/028287
§ 371(c)(1), (2) Date Jan. 24, 2023,
PCT Pub. No. WO2022/025235, PCT Pub. Date Feb. 3, 2022.
Claims priority of application No. 2020-129433 (JP), filed on Jul. 30, 2020.
Prior Publication US 2023/0291384 A1, Sep. 14, 2023
Int. Cl. H03H 9/02 (2006.01); H03H 9/25 (2006.01); H03H 9/64 (2006.01); H04B 1/00 (2006.01)
CPC H03H 9/02574 (2013.01) [H03H 9/25 (2013.01); H03H 9/6483 (2013.01); H04B 1/0057 (2013.01)] 10 Claims
OG exemplary drawing
 
1. An elastic wave element comprising:
a piezoelectric substrate comprising a piezoelectric body and an interdigital transducer (IDT) electrode with a plurality of electrode fingers arranged at predetermined pitches on the piezoelectric body;
a support substrate located on a side opposite to the IDT electrode with respect to the piezoelectric substrate;
a first intermediate layer located between the piezoelectric substrate and the support substrate;
a second intermediate layer located between the first intermediate layer and the support substrate and comprising a constituent element substantially the same to a constituent element of the support substrate, wherein
in the first intermediate layer, a constituent element is substantially the same as a constituent element of the piezoelectric body, an atomic ratio of a metal element is larger than an atomic ratio of a metal element in the piezoelectric body, and an atomic ratio of oxygen is smaller than an atomic ratio of oxygen in the piezoelectric body,
a thickness of the piezoelectric body is equal to or less than five times a maximum pitch among the predetermined pitches, and
a thickness of the second intermediate layer is larger than a thickness of the first intermediate layer.