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. 09, 1995
Filed:
Feb. 28, 1994
Applicant:
Inventors:
Teruyuki Shimura, Itami, JP;
Naohito Yoshida, Itami, JP;
Assignee:
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ; H01L / ; H01L / ;
U.S. Cl.
CPC ...
257 17 ; 257 23 ; 257197 ;
Abstract
A heterojunction bipolar transistor includes a multiquantum barrier structure as part of the collector and contacting the base. The MQB has an energy band structure in which the height of the effective potential barrier of the MQB increases in steps from the base into the collector. Therefore, an electric field in the collector in the vicinity of the base-collector interface is relaxed and intervalley scattering of electrons is suppressed whereby a reduction in electron mobility due to the intervalley scattering is suppressed, reducing transit time of electrons in the collector.