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:
Oct. 05, 1999
Filed:
Apr. 30, 1997
Shinichi Sato, Nara, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A non-volatile semiconductor memory in which a plurality of flash memory cells are arranged in a matrix, each flash memory cell including source and drain regions formed on a silicon substrate, a floating gate formed on at least a part of the source and drain regions with a dielectric film provided therebetween, and a control gate formed on the floating gate with a dielectric layer provided therebetween, wherein a writing operation is performed by applying a positive voltage to the drain region and a negative voltage to the control gate and extracting electrons from the floating gate to the drain region by an FN tunnel current, a common source line for connecting the source region of the flash memory cells includes a diffusion layer formed in the silicon substrate and a silicide formed on the diffusion layer, and impurity concentration of the source region and the common source line are set lower than the impurity concentration of the drain region.