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. 23, 2003
Filed:
Oct. 30, 2001
Kiyoshi Ogata, Yokohama, JP;
Kazuhiko Horikoshi, Kawasaki, JP;
Kazufumi Suenaga, Yokohama, JP;
Hisayuki Kato, Kokubunji, JP;
Keiichi Yoshizumi, Kokubunji, JP;
Masahito Yamazaki, Hinode-machi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
Along life ferroelectric memory device using a thin ferroelectric film capacitor as a memory capacitor is obtained by disposing a plurality of degradation preventive layers on an upper protection electrode and an upper electrode and a degradation preventive layer at the boundary of ferroelectric layer /electrodes or providing a step of decreasing a modified layer at the boundary of ferroelectric layer /upper electrode . This provides a thin ferroelectric film capacitor which is subjected to less fatigue and imprinting and which has less degradation of ferroelectric characteristic to attain a long life ferroelectric memory device.