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:
Feb. 03, 2009
Filed:
May. 15, 2006
Takanori Matsumoto, Mie, JP;
Masahito Shinohe, Mie, JP;
Takanori Matsumoto, Mie, JP;
Masahito Shinohe, Mie, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A semiconductor device includes a semiconductor substrate formed with a trench having a sidewall including a middle point. The trench includes a first part extending from a surface of the semiconductor substrate to the middle point of the trench and having a diameter that is gradually reduced as the first part extends deeper from the surface of the semiconductor substrate to the middle point of the trench. The trench includes a second part that is deeper than the middle point of the sidewall and that has a larger diameter than the middle point of the sidewall. An electrically conductive film is formed in an interior of the trench so as to be located lower than the middle point of the sidewall, the conductive film having a planarized upper surface, and a collar insulating film is formed on the conductive film and the sidewall of the trench so as to extend through the middle point of the sidewall along the sidewall.