Patent ID: 11967946
Assignee: MURATA MANUFACTURING CO., LTD.
Field: Basic communication processes (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. An acoustic resonator device comprising:
a substrate having a surface;
a piezoelectric layer having front and back surfaces;
a bonding layer on the surface of the substrate;
an etch-stop layer sandwiched between the bonding layer and the back surface of the piezoelectric layer, wherein a portion of the piezoelectric layer and the etch-stop layer, but not the bonding layer, form a diaphragm spanning a cavity of the acoustic resonator device; and
an interdigital transducer (IDT) at the piezoelectric layer with interleaved fingers of the IDT disposed on the diaphragm,
wherein the etch-stop layer is impervious to an etch process used to form the cavity.