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:
Apr. 17, 2001
Filed:
Nov. 12, 1998
Shuji Fujiwara, Tokyo, JP;
Toshiyuki Hirota, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A first amorphous silicon layer is formed to connect to a portion of a capacitor contact plug, and then a second amorphous silicon layer and a third amorphous silicon layer are formed thereon. The first and the third amorphous silicon layers are formed so that they have a lower impurity concentration than that in the second amorphous silicon layer. HSG (hemispherical grain) is grown on surfaces of the first and the third amorphous silicon layers, and subsequently an impurity is diffused from the second amorphous silicon layer to the HSG. In such a method for producing a capacitor, the size of the HSG can be appropriately and uniformly controlled, and depletion in the HSG is prevented.