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. 07, 2005
Filed:
Dec. 23, 2003
Ichiro Hase, Kanagawa, JP;
Ichiro Hase, Kanagawa, JP;
Sony Corporation, , JP;
Abstract
A semiconductor device having a heterojunction bipolar transistor capable of suppressing the deterioration of basic transistor characteristics, such as a decline of an injection efficiency from an emitter layer to a base layer due to the rising of emitter resistance, a decline of breakdown strength between the base layer and a collector layer, or a decline of reliability due to an introduction of a defect; configured to comprise a heterojunction bipolar transistor having an emitter layer, base layer and a collector layer, wherein an electron affinity of the base layer is smaller than that of the emitter layer and that of the collector layer, an interlayer is formed at least either between the emitter layer and the base layer or between the base layer and the collector layer, and the electron affinity of the interlayer has a value between the electron affinities of the two layers sandwiching the interlayer.