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. 10, 1995
Filed:
Feb. 14, 1994
Shozo Nishimoto, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A semiconductor memory device having a memory cell including a transistor having, as source and drain regions, impurity-diffused regions formed selectively in the active area isolated by field insulating film formed selectively at the surface of a semiconductor substrate and a capacitor comprising a lower electrode including a bottom electrode and a cylindrical electrode. The bottom electrode is formed on an interlayer insulating film formed over the substrate and is connected to one of the impurity-diffused regions through a first hole opened in said interlayer insulating film. The cylindrical electrode is formed at the edge portion of said bottom electrode and a plurality of second holes formed in the interlayer insulating film on said field insulating film. The first hole and the second holes have substantially the same dimensions except for a depth thereof. The second holes are arranged to be a mark representing characters to assist the process control. In addition, a check element fabricated by forming the lower electrodes covering a plurality of second holes and cylindrical electrodes so that these electrodes assume a loop toothed at a certain pitch can be prevented from being broken down even if the dimensions are large.