PIEZOELECTRIC DEVICE AND METHOD FOR MANUFACTURING 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 method for manufacturing a piezoelectric device including a piezoelectric thin film, a support member bonded to a rear surface of the piezoelectric thin film, a first electrode formed on the rear surface of the piezoelectric thin film, and a cavity formed at a support member side of the first electrode between the piezoelectric thin film and the support member, the method comprising the steps of:
a sacrificial layer formation step of forming a sacrificial layer in an area to be the cavity; an adjustment layer formation step of forming an etching adjustment layer which adjusts progress of etching in a region where the first electrode is exposed to the side of the piezoelectric thin film; an exposure step of simultaneously forming a through hole through which a portion of the sacrificial layer is exposed to a side of the piezoelectric thin film and an opening portion which the first electrode is exposed to a side of the piezoelectric thin film by etching the piezoelectric thin film and the etching adjustment layer; and a sacrificial layer removal step of removing the sacrificial layer through the through hole.