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:
Aug. 14, 2007
Filed:
Jan. 28, 2005
Tomoaki Shino, Kanagawa, JP;
Tomoaki Shino, Kanagawa, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A semiconductor memory device includes transistors, each including a first-conductivity-type semiconductor layer formed on a semiconductor substrate via a first insulating film, a second-conductivity-type source/drain regions formed in the semiconductor layer, a first-conductivity-type body region formed between the source region and the drain region in the semiconductor layer, the body region being electrically floating, and a gate electrode formed on a surface of a central portion of the body region via a second insulating film. In a section along a word line, which connects the gate electrodes together, a length of a boundary between the central portion of the body region and the second insulating film is smaller than a length of a boundary between the body region and the first insulating film. A second-conductivity-type counter impurity is doped in a surface portion of the central portion of the body region on which the second insulating film is formed.