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. 21, 2007
Filed:
Jul. 23, 2004
Tadashi Kadowaki, Osaka, JP;
Hiroyuki Umimoto, Hyogo, JP;
Takato Handa, Shiga, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A semiconductor device comprises varactor regions Va and transistor regions Tr. An active region for a varactor is formed with a substrate contact impurity diffusion region obtained by doping an N well region with N-type impurity at a relatively high concentration. However, any extension region (or LDD region) as in a varactor of a known semiconductor device is not formed in the active region for a varactor. On the other hand, parts of a P well region located to both sides of the polysilicon gate electrode in the transistor region Tr are formed with high-concentration source/drain regions and extension regions. Therefore, the extendable range of a depletion layer is kept wide to extend the capacitance variable range of the varactor.