US 2014/0231382 A1Published application

Piezoelectric device and method for manufacturing piezoelectric device

AssigneeMurata Manufacturing Co., Ltd.

InventorKiyoto ARAKI

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Abstract

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.

Claims14

Dependent claims

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.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 14/259,369Filed 23 Apr 2014
Priority: JP 2010-0261359 Feb 2010
Published: 21 Aug 2014
Term ends: Not estimatedThe source records don’t support an estimate.

Classification17 codes

H10N 30/06
Manufacture or treatment: forming electrodes or interconnections, e.g. leads or terminals
H03H 3/02
For the manufacture of electromechanical resonators or networks: for the manufacture of piezoelectric or electrostrictive resonators or networks
H03H 9/02047
Of bulk acoustic wave devices: treatment of substrates
H03H 9/173
Means for mounting on a substrate, i.e. means constituting the material interface confining the waves to a volume: air-gaps

Family

Application13/568,157Division · filed 7 Aug 2012
Application14/259,369Division
Application13/568,157Continuation
US 2013/0193809 A1Published application
US 8,749,119 B2Related patent
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US 2014/0231382 A1This patent

From the US filing history. Foreign family members aren’t listed.