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. 19, 2006
Filed:
Apr. 01, 2004
Applicants:
Eiju Komuro, Tokyo, JP;
Hisatoshi Saitou, Tokyo, JP;
Yoshinari Yamashita, Tokyo, JP;
Inventors:
Assignee:
TDK Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L 41/04 (2006.01); H03H 9/15 (2006.01);
U.S. Cl.
CPC ...
Abstract
A thin-film bulk acoustic oscillator comprises: a base; a barrier layer disposed on the base; a lower electrode disposed on the barrier layer; a piezoelectric thin film disposed on the lower electrode; and an upper electrode disposed on the piezoelectric thin film. The piezoelectric thin film includes a columnar crystal that extends in the direction intersecting the film surface. The top surface of the piezoelectric thin film is flattened by polishing so as to have a root mean square roughness of 2 nm or smaller.