US 11,800,805 B2
Composite substrate, surface acoustic wave device, and method for manufacturing composite substrate
Shoji Akiyama, Gunma (JP); and Masayuki Tanno, Gunma (JP)
Assigned to SHIN-ETSU CHEMICAL CO., LTD., Tokyo (JP)
Appl. No. 16/348,344
Filed by SHIN-ETSU CHEMICAL CO., LTD., Tokyo (JP)
PCT Filed Oct. 10, 2017, PCT No. PCT/JP2017/036707
§ 371(c)(1), (2) Date May 8, 2019,
PCT Pub. No. WO2018/088093, PCT Pub. Date May 17, 2018.
Claims priority of application No. 2016-220238 (JP), filed on Nov. 11, 2016; and application No. 2017-089666 (JP), filed on Apr. 28, 2017.
Prior Publication US 2020/0058842 A1, Feb. 20, 2020
Int. Cl. H03H 9/02 (2006.01); H10N 30/00 (2023.01); H03H 3/08 (2006.01); H03H 9/25 (2006.01); H10N 30/072 (2023.01); H10N 30/079 (2023.01); H10N 30/086 (2023.01)
CPC H10N 30/10516 (2023.02) [H03H 3/08 (2013.01); H03H 9/02559 (2013.01); H03H 9/02834 (2013.01); H03H 9/02897 (2013.01); H03H 9/25 (2013.01); H10N 30/072 (2023.02); H10N 30/079 (2023.02); H10N 30/086 (2023.02)] 15 Claims
OG exemplary drawing
 
1. A composite substrate comprising:
a piezoelectric single crystal substrate;
a support substrate; and
an intermediate layer provided between the piezoelectric single crystal substrate and the support substrate, wherein
the intermediate layer is a film formed of an inorganic material, and the intermediate layer is separated into at least three layers along a bonding surface of the composite substrate, and the intermediate layer includes:
a first intermediate layer containing a thermally synthesized silica, the first intermediate layer being in contact with the support substrate;
a second intermediate layer provided on the piezoelectric single crystal substrate side of the piezoelectric single crystal substrate; and
a third intermediate layer formed of amorphous silicon,
wherein the first intermediate layer is joined to the second intermediate layer as the third intermediate layer is sandwiched between the first intermediate layer and the second intermediate layer.