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. 09, 1988
Filed:
Dec. 12, 1986
Hiroji Ozaki, Hyogo, JP;
Shinichi Sato, Hyogo, JP;
Akira Tokui, Hyogo, JP;
Akira Kawai, Hyogo, JP;
Masayuki Nakajima, Hyogo, JP;
Masao Nagatomo, Hyogo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A semiconductor memory device comprises a first conductivity type semiconductor substrate (1) formed thereon with a charge storage region (5) and a second conductivity type region (6) serving as a bit line, and first conductivity type highly concentrated regions (8, 11) higher in concentration than the semiconductor substrate (1) at least by one digit are formed to enclose the charge storage region (5) and the bit line region (6) respectively. Thus, potential barriers against electrons can be defined in interfaces between the highly concentrated region (8) and the charge storage region (5) and between the highly concentrated region (11) and the bit line region (6), thereby to prevent malfunction caused by incidence of radioactive rays such as alpha rays.