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:
Jan. 24, 2012
Filed:
Dec. 29, 2008
Yasuhiro Matsumoto, Tokyo, JP;
Yasuji Koshikawa, Tokyo, JP;
Yasuhiro Matsumoto, Tokyo, JP;
Yasuji Koshikawa, Tokyo, JP;
Elpida Memory, Inc., Tokyo, JP;
Abstract
A semiconductor device includes a plurality of memory cells and a sense amplifier circuit which further includes a plurality of elements such as MOS transistor formed in a well, wherein sensitive element, which are sensitive to dispersion of an impurity density in the well, is distanced from a boundary and are disposed in the center region of the well, while non-sensitive element is disposed in the peripheral region close to the boundary in the well. Since sensitive element requiring precise control of threshold voltage is disposed in the center region having uniform impurity density, and non-sensitive element allowing for less precise control of threshold voltage is disposed in the peripheral region suffering from uneven impurity density, it is possible to effectively use the overall area of the well and to thereby suppress an increase in the layout area of chips.