US 11,936,367 B2
Acoustic wave device with velocity reduction cover
Hironori Fukuhara, Ibaraki (JP); and Rei Goto, Osaka (JP)
Assigned to Skyworks Solutions, Inc., Irvine, CA (US)
Filed by Skyworks Solutions, Inc., Irvine, CA (US)
Filed on Oct. 27, 2020, as Appl. No. 17/081,573.
Claims priority of provisional application 62/928,741, filed on Oct. 31, 2019.
Claims priority of provisional application 62/928,792, filed on Oct. 31, 2019.
Prior Publication US 2021/0135654 A1, May 6, 2021
Int. Cl. H03H 9/02 (2006.01); H03H 9/25 (2006.01); H03H 9/64 (2006.01)
CPC H03H 9/25 (2013.01) [H03H 9/02574 (2013.01); H03H 9/02834 (2013.01); H03H 9/6406 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An acoustic wave resonator comprising:
a piezoelectric layer;
an interdigital transducer electrode over the piezoelectric layer, the interdigital transducer electrode having a central region and first and second edge regions on opposing sides of the central region;
a temperature compensation layer over the interdigital transducer electrode; and
a velocity reduction cover extending over at least a portion of the central region of the interdigital transducer electrode and over at least a portion of the temperature compensation layer, the velocity reduction cover arranged to cause a velocity of an acoustic wave generated by the acoustic wave resonator to be reduced, the velocity reduction cover having a multilayer structure including a first sublayer at least partially located over the central region and disposed over the first and second edge regions, and a second sublayer that extends parallel to the first sublayer and is located only over the first and second edge regions of the interdigital transducer electrode.