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:
Feb. 15, 2005
Filed:
Sep. 19, 2002
Takuya Otabe, Fukuyama, JP;
Masaya Nagata, Yokohama, JP;
Takuya Otabe, Fukuyama, JP;
Masaya Nagata, Yokohama, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
On a silicon substrate, there are formed a silicon oxide, an adhesion layerconsisting of TiO, a lower electrodeconsisting of Pt, a ferroelectric thin film, and an upper electrodeconsisting of Pt. A portion of the ferroelectric thin film adjacent to the upper electrodeis formed from a compound with a composition formula of SrBi(TaNb)Owhere x=0.7. A compound with a value x in the composition formula being greater than 0.7 is used for the portion of the ferroelectric thin film adjacent to the upper electrode, so as to generate an appropriate number of grain boundaries on the surface of the ferroelectric film, the grain boundaries enabling implementation of anchoring effect between the ferroelectric filmand the upper electrode, thereby achieving prevention of exfoliation of the upper electrodefrom the ferroelectric film. Therefore, the semiconductor memory device is free from exfoliation of the upper electrode film from the dielectric film and has a good yield.