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:
Jun. 29, 2010
Filed:
Jul. 26, 2006
Hirohisa Yamamoto, Tokyo, JP;
Hirohisa Yamamoto, Tokyo, JP;
Elpida Memory Inc., Tokyo, JP;
Abstract
The present invention provides a method of manufacturing a trench with a rounded corner portion and a broadened opening. Anisotropic oxidation is carried out using a halogen oxidation method using dichloroethylene (DCE) to form an anisotropic oxide film such that the film thickness in a shoulder portion of the trench is thick and gradually decreases nearer the bottom, the anisotropic oxide film is removed, and the shoulder portion of the trench is preferentially backed off, thereby rounding the shoulder portion sufficiently to broaden the opening. Then, an insulating member is embedded in the trench. The rounded portion of the shoulder portion of the trench and vicinity thereof is used as a channel of a MOS transistor.