Title:
PRODUCTION METHOD FOR PIEZOELECTRIC BULK-ACOUSTIC WAVE ELEMENT, AND PIEZOELECTRIC BULK-ACOUSTIC WAVE ELEMENT
Document Type and Number:
WIPO Patent Application WO/2013/125371
Kind Code:
A1
Abstract:
Provided is a method with which a piezoelectric bulk-acoustic wave element exhibiting excellent properties can be produced. A sacrificial layer (21) is formed above one section of a main surface (10a) of a substrate (10). A piezoelectric film (11a) which is sandwiched between a pair of electrodes (11b, 11c), and which comprises scandium-containing aluminium nitride having a concentration (number of scandium atoms/(number of scandium atoms+number of aluminium atoms)) of scandium atoms relative to the total number of scandium atoms and aluminium atoms of more than 24 at.%, is formed above the main surface (10a) of the substrate (10) such that the sacrificial layer (21) is covered. An etching step, in which the sacrificial layer (21) is removed by etching, is performed. Prior to the etching step, a protective layer (13) comprising either aluminium nitride or scandium-containing aluminium nitride having a concentration of scandium atoms which is less than that of the piezoelectric film (11a) is provided so as to cover at least one section located in the area in which the sacrificial layer (21) for the piezoelectric film (11a) is provided.
Inventors:
ARAKI KIYOTO (JP)
UMEDA KEIICHI (JP)
UMEDA KEIICHI (JP)
Application Number:
PCT/JP2013/053042
Publication Date:
August 29, 2013
Filing Date:
February 08, 2013
Export Citation:
Assignee:
MURATA MANUFACTURING CO (JP)
International Classes:
H03H3/02; H01L41/09; H01L41/18; H01L41/22; H03H9/17
Foreign References:
| JP2008172713A | 2008-07-24 | |||
| JP2009010926A | 2009-01-15 | |||
| JP2011015148A | 2011-01-20 | |||
| JP2008160322A | 2008-07-10 | |||
| JP2008022305A | 2008-01-31 |
Attorney, Agent or Firm:
MIYAZAKI & METSUGI (JP)
Patent business corporation Miyazaki and table-of-contents patent firm (JP)
Patent business corporation Miyazaki and table-of-contents patent firm (JP)
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Claims:
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