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:
Jun. 27, 2000
Filed:
Dec. 04, 1997
Applicant:
Inventors:
Shinichi Miyakuni, Tokyo, JP;
Teruyuki Shimura, Tokyo, JP;
Assignee:
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ; H01L / ; H01L / ;
U.S. Cl.
CPC ...
257197 ; 257198 ; 257582 ; 438312 ;
Abstract
A heterojunction bipolar transistor is provided with a ballast resistor layer in an emitter layer which prevents the current amplification factor .beta. from decreasing. The n-GaAs carrier supply layer having a specified carrier concentration is formed between the ballast resistor layer and the n-AlGaAs layer.