Patent ID: 11876498
Assignee: MURATA MANUFACTURING CO., LTD.
Field: Basic communication processes (Electrical engineering)
Classification: CPC H | IPC H

Claim 9:
10. A method of fabricating a filter device, comprising:
attaching a back surface of at least one piezoelectric layer having a first thickness to a substrate or one or more intermediate material layers on the substrate;
selectively forming a recess in a front surface of the piezoelectric layer to thin a portion of the piezoelectric layer from the first thickness to a second thickness less than the first thickness;
forming a plurality of cavities in at least one of the substrate and the one or more intermediate material layers, such that portions of the at least one piezoelectric layer form a plurality of diaphragms spanning respective cavities; and
forming a conductor pattern at the at least one piezoelectric layer, the conductor pattern comprising
a first interdigital transducer (IDT) with interleaved fingers on a first diaphragm having the first thickness, and
a second IDT with interleaved fingers on a second diaphragm having the second thickness.