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:
Feb. 21, 1989
Filed:
Jul. 15, 1988
Farrokh Mohammadi, Mountain View, CA (US);
Chan S Pang, Sunnyvale, CA (US);
National Semiconductor Corp., Santa Clara, CA (US);
Abstract
The present invention provides a single-poly electrically erasable programmable read only memory device which is formed in a semiconductor substrate of a first conductivity type. The memory device includes a pass cell comprising first and second regions of a second conductivity type, opposite to that of the first conductivity type, formed in the substrate. The first and second regions are separated by a first channel region formed by the substrate. A first conductive portion is formed over the first channel region and is separated from the first channel region by a dielectric material. A control cell comprising third and forth regions of the second conductivity type is also formed in the substrate. The third and forth regions are separated by a second channel region formed by the substrate. The first conductive portion extends over the second channel region and is separated from the second channel region by the dielectric material. The device also includes a memory cell comprising a second region and a fifth region of the second conductivity type formed in the substrate. The second and the fifth regions are separated by a third channel region formed by the substrates. A second conductive portion is formed over the third channel region and overlaps the second region. The second conductive portion is separated from the second region and the third channel region by the dielectric material.