Piezoelectric device

摘要

A piezoelectric device prevents damage to a piezoelectric thin film caused by etching and the manufacturing cost of the piezoelectric device is reduced. On a surface of a support layer formed on a support substrate, an etching adjustment layer is formed. An etchant flows through etching windows to simultaneously form a through hole through which a portion of a sacrificial layer is exposed to a side of a piezoelectric thin film and an opening through which the etching adjustment layer, which is conductive with a lower electrode, is exposed to the side of the piezoelectric thin film. By making an etchant flow through the through hole, the sacrificial layer is removed. A lead-out wiring is formed between an upper electrode and a bump pad and a lead-out wiring is formed between the conductive etching adjustment layer, which is conductive with the lower electrode, and a bump pad.

主权项

1. A piezoelectric device, comprising:
a piezoelectric thin film; a support member bonded to a rear surface of the piezoelectric thin film; a first electrode located on the rear surface of the piezoelectric thin film; a cavity located at a support member side of the first electrode between the piezoelectric thin film and the support member; a conductive etching adjustment layer arranged to adjust progress of etching, the etching adjustment layer being disposed on a piezoelectric thin film side of the support member, directly or so as to electrically connect through the first electrode; a through hole extending through the piezoelectric thin film and communicating with the cavity; and an opening portion through which the etching adjustment layer is exposed to a side of the piezoelectric thin film.