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. 23, 2004
Filed:
Aug. 21, 2002
Applicant:
Inventors:
Takeshi Takagi, Kyoto, JP;
Koichiro Yuki, Osaka, JP;
Kenji Toyoda, Osaka, JP;
Yoshihiko Kanzawa, Osaka, JP;
Assignee:
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L 2/122 ;
U.S. Cl.
CPC ...
H01L 2/122 ;
Abstract
A heterojunction bipolar transistor is fabricated by stacking a Si collector layer, a SiGeC base layer and a Si emitter layer in this order. By making the amount of a lattice strain in the SiGeC base layer on the Si collector layer 1.0% or less, the band gap can be narrower than the band gap of the conventional practical SiGe (the Ge content is about 10%), and good crystalline can be maintained after a heat treatment. As a result, a narrow band gap base with no practical inconvenience can be realized.