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. 22, 2011
Filed:
Nov. 29, 2007
Haruhiko Koyama, Yokohama, JP;
Haruhiko Koyama, Yokohama, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A semiconductor memory device includes a well layer having a first conductivity type and formed in a semiconductor substrate, a block layer formed in a trench and formed of an insulating layer, a gate electrode formed on the semiconductor substrate apart from the block layer, a first diffusion layer having a second conductivity type, formed on a surface of the semiconductor substrate, and having a high impurity concentration region to a first depth from the surface of the semiconductor substrate, a second diffusion layer having the second conductivity type, formed on the surface of the semiconductor substrate on a side of the block layer away from the gate electrode, having a high impurity concentration region to a second depth greater than the first depth from the surface of the semiconductor substrate, and electrically connected to the first diffusion layer, and a contact connected to the second diffusion layer.