Patent ID: 11967943
Assignee: MURATA MANUFACTURING CO., LTD.
Field: Basic communication processes (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 16:
17. A filter device, comprising:
a substrate having a front surface;
at least one piezoelectric plate supported by the front surface of the substrate;
a plurality of interdigital transducers (IDTs) of a respective plurality of acoustic resonators including at least one shunt resonator and at least series resonator, interleaved fingers of each of the plurality of IDTs disposed on a respective diaphragm of one or more diaphragms spanning respective cavities; and
an etch-stop layer on the at least one piezoelectric plate and between interleaved fingers of the plurality of IDTs,
wherein the etch-stop layer is a material configured to be impervious to at least one etch process capable of etching the interleaved fingers.