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. 08, 1994
Filed:
Sep. 11, 1992
Manabu Ando, Tokyo, JP;
Hiroshi Furuta, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A static memory device has memory cells each having a pair of driver MOSFETs, two load resistors each connected between a power source and a drain of each of the driver MOSFETs, two access MOSFETs each of which is connected between the drain of each of the driver MOSFETs and each of bit lines and gates of which are connected to a word line. In the memory cell, the thickness of a gate oxide film of the access MOSFET is made thicker than that of the gate oxide film of the driver MOSFET. The operation stability of the memory cell is enhanced, without the need of increasing a chip size, by increasing a ratio between the driver MOSFETs and the access MOSFETs of the memory cell (the ratio of current supplying capabilities of the two transistors) without making a gate size large or without making it so small as to cause process variations.