US 12,136,907 B2
Composite substrate for surface acoustic wave device and manufacturing method thereof
Masayuki Tanno, Gunma (JP); and Shoji Akiyama, Gunma (JP)
Assigned to Shin-Etsu Chemical Co., Ltd., Tokyo (JP)
Filed by Shin-Etsu Chemical Co., Ltd., Tokyo (JP)
Filed on May 5, 2021, as Appl. No. 17/308,422.
Claims priority of application No. 2020-086299 (JP), filed on May 15, 2020.
Prior Publication US 2021/0359660 A1, Nov. 18, 2021
Int. Cl. H03H 9/02 (2006.01); H03H 3/08 (2006.01); H03H 9/64 (2006.01); H10N 30/00 (2023.01); H10N 30/072 (2023.01)
CPC H03H 9/02551 (2013.01) [H03H 3/08 (2013.01); H03H 9/02574 (2013.01); H03H 9/6483 (2013.01); H10N 30/072 (2023.02); H10N 30/706 (2024.05)] 16 Claims
OG exemplary drawing
 
1. A composite substrate for a surface acoustic wave device, comprising a piezoelectric single crystal thin film, a support substrate, and a first intervening layer between the piezoelectric single crystal thin film and the support substrate, wherein:
the first intervening layer is in contact with the piezoelectric single crystal thin film; and
an acoustic velocity of a transverse wave of the first intervening layer is faster than an acoustic velocity of a fast transverse wave of the piezoelectric single crystal thin film,
wherein:
a second intervening layer is provided between the first intervening layer and the support substrate; and
an acoustic velocity of a transverse wave of the second intervening layer is slower than an acoustic velocity of a fast transverse wave of the piezoelectric single crystal thin film.