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:
May. 25, 2010
Filed:
Nov. 21, 2007
Eiji Hasunuma, Tokyo, JP;
Eiji Hasunuma, Tokyo, JP;
Elpida Memory, Inc., Chuo-ku, Tokyo, JP;
Abstract
A semiconductor device is provided which is suitable for a DRAM with word lines and configured to have a trench gate transistor and suppress an increase in the capacitance of a word line without affecting the transistor characteristics. The semiconductor device includes a trench gate transistor which is provided with: a trench which is provided with vertical sides and is formed in a semiconductor substrate; a gate electrode which is formed inside the trench via a gate dielectric film; and a source and a drain which are provided at the semiconductor substrate in the vicinity of the gate electrode via the gate dielectric film, wherein at least one of the thickness of the gate dielectric film in a region contacting the source and the thickness of the gate dielectric film in a region contacting the drain are larger than the thickness of the gate dielectric film formed inside the trench.