US 11,705,885 B2
Transversely-excited film bulk acoustic resonator with lateral etch stop
Patrick Turner, San Bruno, CA (US); Carolyn Bianco, San Francisco, CA (US); and Charles Chung, San Francisco, CA (US)
Assigned to Murata Manufacturing Co., Ltd., Nagaokakyo (JP)
Filed by Murata Manufacturing Co., Ltd., Nagaokakyo (JP)
Filed on Dec. 2, 2020, as Appl. No. 17/109,827.
Application 17/109,827 is a continuation of application No. 16/913,417, filed on Jun. 26, 2020, granted, now 10,911,021.
Claims priority of provisional application 62/867,685, filed on Jun. 27, 2019.
Claims priority of provisional application 62/904,407, filed on Sep. 23, 2019.
Prior Publication US 2021/0091747 A1, Mar. 25, 2021
Int. Cl. H03H 9/17 (2006.01); H03H 9/02 (2006.01); H03H 3/02 (2006.01); H03H 9/13 (2006.01); H10N 30/06 (2023.01)
CPC H03H 9/17 (2013.01) [H03H 3/02 (2013.01); H03H 9/02015 (2013.01); H03H 9/13 (2013.01); H10N 30/06 (2023.02)] 18 Claims
OG exemplary drawing
 
1. An acoustic resonator device comprising:
a substrate having a cavity and comprising a substrate material;
a lateral etch-stop that defines a perimeter of the cavity, the lateral etch-stop comprising a lateral etch-stop material different from the substrate material;
a single-crystal piezoelectric plate attached to the substrate except for a portion of the piezoelectric plate forming a diaphragm that spans the cavity; and
an interdigital transducer (IDT) at the piezoelectric plate such that interleaved fingers of the IDT are at the diaphragm,
wherein the piezoelectric plate and the IDT are configured such that a radio frequency signal applied to the IDT excites a primary shear acoustic mode in the diaphragm.