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. 22, 1991
Filed:
Oct. 25, 1989
Hideaki Shimizu, Inagi, JP;
Nobuyuki Yamamura, Hanno, JP;
Hiroyasu Yamada, Fussa, JP;
Haruo Wakai, Hamura, JP;
Hiroshi Matsumoto, Tachikawa, JP;
Casio Computer Co., Ltd., Tokyo, JP;
Abstract
A memory device includes a memory element composed of a first thin film transistor having a memory function, and a select element composed of a second thin film transistor for selecting the memory element. A gate insulation film of the first thin film transistor has a charge storage function. A gate insulation film of the second thin film transistor does not have any charge storage function. If a plurality of the memory devices are arranged in matrix form, this configuration can be used as E.sup.2 PROM. By forming the first and second thin film transistors simultaneously, it is possible to form the first and second thin film transistors easily in the simple manufacturing steps.