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:
Jul. 26, 1994
Filed:
Apr. 23, 1993
Tetsuro Nozu, Tokyo, JP;
Norio Iizuka, Yokohama, JP;
Junko Akagi, Kawasaki, JP;
Torakiti Kobayashi, Yokohama, JP;
Masao Obara, Tokyo, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A heterojunction bipolar transistor comprises n.sup.+ -type GaAs collector contact region, an n-type GaAs collector region, a p.sup.+ -type GaAs base region, an n-type AlGaAs emitter region, and an n.sup.+ -type InGaAs emitter contact region, all of which are formed on a semiinsulative GaAs substrate. A heterojunction is formed by the base region and the emitter region. The emitter region is formed in mesa shape by dry etching. Around this mesa, B.sup.+ ion-implanted high-resistance region is formed. The base-emitter Junction is isolated from the ion-implanted region. The heterojunction bipolar transistor therefore has little on-voltage changes.