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.

Date of Patent:
Jun. 30, 2009

Filed:

Jan. 25, 2006
Applicants:

Ryota Yamamoto, Kanagawa, JP;

Kuniko Kikuta, Kanagawa, JP;

Inventors:

Ryota Yamamoto, Kanagawa, JP;

Kuniko Kikuta, Kanagawa, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L 29/76 (2006.01);
U.S. Cl.
CPC ...
Abstract

An N-type deep well is used to protect a circuit from a noise. However, a noise with a high frequency propagates through the N-type deep well, and as a result, the circuit that should be protected malfunctions. To reduce the area of the N-type deep well. For instance, in the present invention, a semiconductor device comprises a semiconductor substrate of a first conductivity type, a digital circuit part and an analog circuit part provided on the semiconductor substrate, a plurality of wells of the first conductivity type formed in either the analog circuit part or the digital circuit part, and a first deep well of a second conductivity type, which is the opposite conductivity type to the first conductivity type, isolating some of the plurality of wells from the semiconductor substrate.


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