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. 15, 1999
Filed:
Jun. 06, 1997
Yuukoh Katoh, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A non-volatile ferroelectric memory cell includes a ferroelectric capacitor polarized in either direction representative of one of the logic levels of a data bit and a field effect transistor connected between a bit line and a ground line and having a gate electrode connected to one of the electrodes of the ferroelectric capacitor, and the polarization in the ferroelectric capacitor induces movable electric charge in the gate electrode so as to change the threshold of the field effect transistor between a high level and a low level; when the movable electric charge is undesirably leaked from the gate electrode, a data restoring circuit checks the ferroelectric capacitor to see whether the polarization is directed in one direction or the other direction, and a driving circuit makes up the movable electric charge so as to enhance the reliability of the data bit stored therein.