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:
Nov. 04, 2003
Filed:
Feb. 04, 2002
Teruhito Ohnishi, Hirakata, JP;
Takeshi Takagi, Kyoto, JP;
Akira Asai, Osaka, JP;
Taizo Fujii, Kyoto, JP;
Mitsuo Sugiura, Kanzaki-gun, JP;
Yoshihisa Minami, Otsu, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A variable capacitor includes an N layer including a variable capacitance region, a P layer epitaxially grown on the N layer and formed from a SiGe film and a Si film, and a P-type electrode. An NPN-HBT (Hetero-junction Bipolar Transistor) includes a collector diffusion layer formed simultaneously with the N layer of the variable capacitor, a collector layer, and a Si/SiGe layer epitaxially grown simultaneously with the P layer of the variable capacitor. Since a depletion layer formed in a PN junction of the variable capacitor can extend entirely across the N layer, reduction in variation range of the capacitance can be suppressed.