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. 04, 1997
Filed:
Sep. 29, 1995
Natsuo Ajika, Hyogo, JP;
Masahiro Hatanaka, Hyogo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
An object of the present invention is to achieve an improved flash memory which enables to simultaneously obtain high performance and reliability even with voltage V.sub.CC of 3.3 V or below. The device includes a memory cell 6, a V.sub.CC type transistor 7 and a V.sub.PP type transistor 8. Memory cell 6 includes a tunnel oxide film 2, a floating gate 3 and a control gate 4. A V.sub.CC type transistor 7 includes a first gate insulating film 9 and a first gate 10. A V.sub.PP type transistor 8 includes a second gate insulating film 11 and a second gate 12. An inequality, t(V.sub.CC)<t(TN)<t(V.sub.PP), is satisfied where t(TN) is the thickness of the tunnel oxide film, t(V.sub.CC) is the thickness of the first gate insulating film, and t(V.sub.PP) is the thickness of the second gate insulating film.