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:
Jan. 02, 1996
Filed:
May. 20, 1993
Applicant:
Inventor:
Toshiaki Ogawa, Hyogo, JP;
Assignee:
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ; H01L / ;
U.S. Cl.
CPC ...
257308 ; 257532 ; 257401 ;
Abstract
In a semiconductor device with improved lifetime of a capacitor insulating film, a standing wall portion forming a capacitor lower electrode has a substantially round tip end and a side surface, of which roughness is not more than 200 .ANG.. This suppresses concentration of electric field at the tip end of the standing wall portion, and also suppresses irregularity in electric field at its side surface. Thereby, the lifetime of the capacitor insulating film is improved.