US 12,249,971 B2
Transversely-excited film bulk acoustic resonators with solidly mounted resonator (SMR) pedestals
Ventsislav Yantchev, Sofia (BG)
Assigned to MURATA MANUFACTURING CO., LTD., Nagaokakyo (JP)
Filed by Murata Manufacturing Co., Ltd., Nagaokakyo (JP)
Filed on Feb. 17, 2022, as Appl. No. 17/674,783.
Application 17/674,783 is a continuation in part of application No. 17/494,657, filed on Oct. 5, 2021.
Claims priority of provisional application 63/169,874, filed on Apr. 2, 2021.
Prior Publication US 2022/0321082 A1, Oct. 6, 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 3/02 (2013.01) [H03H 9/02228 (2013.01); H03H 9/132 (2013.01); H03H 9/174 (2013.01); H03H 9/175 (2013.01); H03H 2003/023 (2013.01); H03H 2003/025 (2013.01)] 21 Claims
OG exemplary drawing
 
1. A method of fabricating an acoustic resonator with a Bragg reflector having pedestals and configured to reflect shear acoustic waves at a resonance frequency of the acoustic resonator, comprising:
forming plural Bragg reflector layers on a top surface of a silicon substrate;
masking over the plural Bragg reflector layers at a plurality of pedestal locations for the pedestals of the Bragg reflector;
removing one or more top layers of the Bragg reflector layers from between the pedestal locations to form the pedestals and to form a cavity with a cavity top surface perimeter;
bonding a top surface of the pedestals and the cavity top surface perimeter to a plate front surface of a piezoelectric plate having the plate front surface, a plate back surface, and a sacrificial substrate bonded to the plate back surface;
removing the sacrificial substrate from the plate back surface to leave the piezoelectric plate bonded to the pedestals and standing over the cavity; and
forming at least one conductor pattern on the plate front surface.