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:
Aug. 23, 2005
Filed:
Aug. 01, 2003
Satoshi Takahashi, Kawasaki, JP;
Minoru Yamashita, Kawasaki, JP;
Satoshi Takahashi, Kawasaki, JP;
Minoru Yamashita, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A nonvolatile memory has a plurality of memory cells, each of the memory cells having a first and a second source/drain areas, a control gate, and an insulating trap layer disposed between the control gate and a channel area lying between the first and the second source/drain areas. The trap layer includes a use bit area in proximity to the first source/drain area, for storing data depending on the presence or absence of electric charge to be trapped, and a non-use bit area in proximity to the second source/drain area, in which the electric charge is trapped while data is held in the use bit area. Preferably, in the state where erasing operation is completed, the non-use bit area is brought into a state where electric charge is trapped therein.