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. 05, 1999
Filed:
Nov. 24, 1997
Applicant:
Inventors:
Assignee:
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ; H01L / ; H01L / ;
U.S. Cl.
CPC ...
257309 ; 257307 ; 257308 ; 438239 ; 438241 ; 438251 ; 438252 ; 438254 ; 438255 ; 438256 ; 438394 ; 438398 ;
Abstract
In the semiconductor device according to the invention, a tubular storage node is formed, then slanting rotation implantation of impurity phosphorus ions is executed for changing the phosphorus concentration and the etching rate at the thermal phosphoric acid treatment time is changed for roughening the surface under good control. Since the surface roughening does not extend to the center of the film of the storage node, the strength of the storage node can be held sufficient. Therefore, the capacitance can be increased.