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:
Jul. 12, 2011
Filed:
Sep. 15, 2009
Koji Shimosako, Kawasaki, JP;
Koji Shimosako, Kawasaki, JP;
Fujitsu Semiconductor Limited, Yokohama, JP;
Abstract
Dummy memory cells are disposed on an outside of real memory cells positioned on a peripheral part of a matrix. First contacts coupling between two wiring layers laminated on a semiconductor substrate are disposed around each of the real and dummy memory cells, and are shared by an adjacent real or dummy memory cell. Number of the first contacts disposed in each of the dummy memory cells is set to be smaller than number of the first contacts disposed in each of the real memory cells. Accordingly, even when a well region is not formed normally due to a variation in manufacturing conditions, it is possible to prevent an abnormal power supply current from being flown into the dummy memory cells, and an occurrence of latch up can be prevented.