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:
Jun. 21, 2011
Filed:
Aug. 24, 2007
Kazuki Iwashita, Ube, JP;
Keigo Nagao, Ube, JP;
Shinji Fukuda, Ube, JP;
UBE Industries, Ltd., Yamaguchi, JP;
Abstract
A thin film piezoelectric resonator suppresses deterioration of impedance at antiresonant frequency and has a high Q value. The thin film piezoelectric resonator is provided with a semiconductor substrate (); an insulating layer () formed on the semiconductor substrate () in contact with the surface of the semiconductor substrate; and a piezoelectric resonator stack () formed above the insulating layer and having a lower electrode (), a piezoelectric layer () and an upper electrode () in this order from the insulating layer side. An oscillation space () is formed corresponding to an oscillation region where the lower electrode () and the upper electrode () of the piezoelectric resonator stack () overlap each other in the thickness direction. The fixed charge density in the insulating layer () is 1×10cmor less. At the time of manufacturing the thin film piezoelectric resonator, the insulating layer is formed in contact with the semiconductor substrate and then, heat treatment at 300° C. or higher is performed under non-oxygenated atmosphere.