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. 16, 1994
Filed:
May. 27, 1993
Applicant:
Inventor:
Takeshi Kasahara, Tsurugashima, JP;
Assignee:
Toko Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
257597 ; 257595 ; 257596 ;
Abstract
There is provided a variable capacitance diode device. The device comprises a semiconductor substrate of a first conductive type, an epitaxial layer of the first conductive type with a high specific resistance formed on the semiconductor substrate, a first diffusion layer of the first conductive type, in which impurities are more diffused than the epitaxial layer, formed in the epitaxial layer and a second diffusion layer of a second conductive type which forms a junction with the first diffusion layer. The first diffusion layer is formed in a hollow cylindrical body or a hollow square pole body, etc., so as to enlarge an outer peripheral area thereof.