The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 01, 2009
Filed:
Aug. 10, 2007
Yasuo Osone, Kasumigaura, JP;
Chiko Yorita, Fujisawa, JP;
Yuji Shirai, Hamura, JP;
Seiichi Tomoi, Saku, JP;
Yasuo Osone, Kasumigaura, JP;
Chiko Yorita, Fujisawa, JP;
Yuji Shirai, Hamura, JP;
Seiichi Tomoi, Saku, JP;
Renesas Technology Corp., Tokyo, JP;
Abstract
A technique capable of integrally forming SMR type acoustic wave filters corresponding to multiple bands on the same chip at low cost is provided. In SMR type acoustic wave filters including multiple bandpass filters corresponding to multiple bands formed over the same die (substrate), acoustic multilayer films are formed without or with a minimum number of masks and piezoelectric thin films having different thicknesses for respective bands are collectively formed. For example, after the acoustic multilayer films (low acoustic impedance layers and high acoustic impedance layers) are formed in a deep groove in a terrace paddy field shape over the die in a maskless manner, the piezoelectric thin films are c-axis-oriented and grown, and are polished by CMP method or the like to be adjusted in a thickness for respective bands, and therefore, the SMR type acoustic wave filters for multiple bands are formed over the same chip.