US 12,456,961 B2
Acoustic wave device and wafer with support substrate having an uneven surface, and manufacturing method of wafer
Shinji Yamamoto, Tokyo (JP); and Michio Miura, Tokyo (JP)
Assigned to TAIYO YUDEN CO., LTD., Tokyo (JP)
Filed by TAIYO YUDEN CO., LTD., Tokyo (JP)
Filed on Aug. 31, 2021, as Appl. No. 17/462,543.
Claims priority of application No. 2020-158550 (JP), filed on Sep. 23, 2020.
Prior Publication US 2022/0094330 A1, Mar. 24, 2022
Int. Cl. H03H 3/02 (2006.01); H03H 9/02 (2006.01); H03H 9/13 (2006.01); H03H 9/17 (2006.01)
CPC H03H 9/173 (2013.01) [H03H 3/02 (2013.01); H03H 9/02015 (2013.01); H03H 9/02157 (2013.01); H03H 9/131 (2013.01); H03H 9/132 (2013.01)] 13 Claims
OG exemplary drawing
 
1. An acoustic wave device comprising:
a support substrate having an uneven surface;
a piezoelectric layer provided on the uneven surface of the support substrate;
an electrode that excites an acoustic wave in the piezoelectric layer; and
an insulating layer that is provided between the uneven surface of the support substrate and the piezoelectric layer, and has an air gap located in a recess part of the uneven surface, an upper portion of the air gap being covered with the insulating layer and a side portion of the air gap being surrounded by the insulating layer.