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:
Nov. 10, 1992
Filed:
Aug. 24, 1990
Applicant:
Inventor:
Shuichi Ohya, Tokyo, JP;
Assignee:
NEC Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ; H01L / ; H01L / ;
U.S. Cl.
CPC ...
257309 ; 257634 ; 257758 ;
Abstract
A semiconductor memory device is fabricated on a semiconductor substrate and comprises a memory cell array having a plurality of memory cells and located in a predetermined cell area of the semiconductor substrate, a rampart structure formed outside the memory cell array and having an outer wall gently sloping down, an upper insulating layer convering the memory cells and the rampart structure, and at least one wiring layer formed on the upper insulating layer and extending over at least one of the memory cells and the rampart structure, whereby the wiring layer is prevented from non-conformal step coverage and any disconnection.