Chan Sui Pang

US Patent:

48070033, Feb 21, 1989

Filed:

Jul 15, 1988

Appl. No.:

7/220927

Inventors:

Farrokh Mohammadi - Mountain View CA
Chan S. Pang - Sunnyvale CA

Assignee:

National Semiconductor Corp. - Santa Clara CA

International Classification:

H01L 2978

US Classification:

357 235

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.