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. 01, 2007
Filed:
Apr. 07, 2004
Susumu Kurosawa, Kanagawa, JP;
Yuki Fujimoto, Kanagawa, JP;
Yasutaka Nakashiba, Kanagawa, JP;
NEC Electronics Corporation, Kanagawa, JP;
Abstract
An N well is disposed in the upper surface of a P type substrate, a gate insulating film and a gate electrode are disposed thereon, and the gate electrode is connected to a gate terminal. Two pdiffusion regions are placed in two areas in the surface of the N well sandwiching the gate electrode, and the pdiffusion regions are connected to a ground potential wiring. Further, an ndiffusion region is disposed in the surface of the N well, and is connected to a well terminal. Accordingly, capacitance is generated between the gate electrode and the N well of a varactor element. When the potential of the gate terminal is decreased, the two pdiffusion regions absorb positive holes serving as minority carriers from a channel region.