Device comprising an acoustic layer and via interconnect

A method for fabricating an acoustic device, comprising:

• providing a lid layer;
• coupling an acoustic layer to the lid layer, wherein the acoustic layer comprises:
• a piezoelectric layer;
• a dielectric layer;
• at least one material layer located in the dielectric layer;
• and
• a plurality of interconnects coupled to the piezoelectric layer,
• wherein the acoustic layer is coupled to the lid layer such that a cavity is located between the lid layer and the piezoelectric layer;
• coupling a substrate to the dielectric layer of the acoustic layer;
• and
• forming at least one via interconnect that is coupled to the piezoelectric layer through the plurality of interconnects, wherein the at least one via interconnect extends through the dielectric layer and the substrate.