N-polar rare-earth iii-nitride bulk acoustic wave resonator

Abstract

A bulk acoustic wave (BAW) resonator includes a piezoelectric layer oriented so that an N-polar surface forms a frontside surface that faces away from the substrate while a metal-polar surface forms the backside surface and faces toward the substrate. A process for the manufacture of a bulk acoustic wave (BAW) resonator includes orienting a piezoelectric layer on a substrate so that an N-polar surface forms a frontside surface that faces away from the substrate while a metal-polar surface forms the backside surface and faces toward the substrate; etching a via though the backside of the substrate to the metal-polar surface of the piezoelectric layer; and removing etch residue from a sidewall of the resonator cavity.

Dependencies are inferred from the claim text.