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. 18, 2010
Filed:
Jul. 06, 2004
Tohru Saitoh, Ibaraki, JP;
Takahiro Kawashima, Osaka, JP;
Ken Idota, Moriguchi, JP;
Yoshihiko Kanzawa, Yawata, JP;
Teruhito Ohnishi, Hirakata, JP;
Tohru Saitoh, Ibaraki, JP;
Takahiro Kawashima, Osaka, JP;
Ken Idota, Moriguchi, JP;
Yoshihiko Kanzawa, Yawata, JP;
Teruhito Ohnishi, Hirakata, JP;
Panasonic Corporation, Osaka, JP;
Abstract
A bipolar transistorcomprises a substrate, a intrinsic base regionand an extrinsic base region. The intrinsic base regioncomprises a silicon buffer layercomprised of silicon which is formed on the substrate, and a composition-ratio graded base layerwhich is formed on the silicon buffer layer and comprises silicon and at least germanium and where a composition ratio of the germanium to the silicon varies in a thickness direction of the composition-ratio graded base layer. The extrinsic base regioncomprises an extrinsic base formation layercomprised of silicon which is formed on the substrate and adjacent to the silicon buffer layer. And the thickness of the extrinsic base formation layeris not less than 40 nm.