Patent ID: 11949399
Assignee: MURATA MANUFACTURING CO., LTD.
Field: Basic communication processes (Electrical engineering)
Classification: CPC H | IPC H

Claim 17:
18. A method of fabricating a filter device, the method comprising:
forming an acoustic Bragg reflector by depositing material layers on one or both of a surface of a substrate and a first surface of at least one piezoelectric layer having a surface attached to a sacrificial substrate;
bonding the at least one piezoelectric layer attached to the sacrificial substrate to the substrate such that the layers of the acoustic Bragg reflector are sandwiched between the at least one piezoelectric layer and the surface of the substrate;
removing the sacrificial substrate to expose the surface of the at least one piezoelectric layer; and
forming a conductor pattern at the at least one piezoelectric layer, the conductor pattern including a plurality of interdigital transducers (IDTs) of a respective plurality of acoustic resonators including a shunt resonator,
wherein the acoustic Bragg reflector comprises alternating SiO2 and diamond layers and is configured to reflect a resonant frequency of the respective plurality of acoustic resonators, and
wherein an electric field of the resonance frequency is predominantly lateral while a direction of acoustic energy flow of a primary shear acoustic mode of the plurality of acoustic resonators is substantially orthogonal to the electric field.