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:
Sep. 29, 2009
Filed:
Nov. 29, 2006
Satoru Isogai, Tokyo, JP;
Satoru Isogai, Tokyo, JP;
Elpida Memory, Inc., Tokyo, JP;
Abstract
A short circuit with an adjacent hole is prevented. By enlarging a hole diameter in the lower part of the hole, a stable storage node is formed without causing a decrease in capacitance. Provided is a method for production of a semiconductor device, comprising the steps of: forming the second hole in the second insulating film to a depth at which a bowing shape does not occur by carrying out anisotropic etching; forming the fourth film on the side surfaces of the first and the second holes; forming the second hole of an aspect ratio greater than 12 by extending the second hole until the first insulating film is exposed by carrying out anisotropic etching; and extending by isotropic etching a side surface portion of the second hole on which the fourth film is not formed.