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:
Mar. 12, 2002
Filed:
Sep. 27, 1996
Hisayoshi Yamoto, Kanagawa, JP;
Akihiko Ochiai, Kanagawa, JP;
Sony Corporation, Tokyo, JP;
Abstract
A capacitor in a ferroelectric nonvolatile memory (FERAM) comprising a lower electrode formed on a semiconductor substrate; a ferroelectric thin film formed on the lower electrode; an upper electrode formed on the ferroelectric thin film; a first protective layer consisting of one or more layers formed between the semiconductor substrate and the lower electrode, and composed of a material selected from those of Group IVa transition metal, Group Va transition metal, Group IVa transition metal nitride, Group Va transition metal nitride, silicon nitride, nickel and palladium; and a second protective layer consisting of one or more layers formed on the upper electrode, and composed of a material selected from those of Group IVa transition metal, Group Va transition metal, Group IVa transition metal nitride, Group Va transition metal nitride, nickel and palladium. Since the ferroelectric capacitor is enclosed with composite films of such materials, it becomes possible to prevent diffusion of hydrogen and intrusion of water content therein to consequently avert deterioration of the characteristics.