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. 01, 2010
Filed:
Dec. 21, 2006
Keiichi Murayama, Toyama, JP;
Akiyoshi Tamura, Osaka, JP;
Hirotaka Miyamoto, Toyama, JP;
Kenichi Miyajima, Toyama, JP;
Keiichi Murayama, Toyama, JP;
Akiyoshi Tamura, Osaka, JP;
Hirotaka Miyamoto, Toyama, JP;
Kenichi Miyajima, Toyama, JP;
Panasonic Corporation, Osaka, JP;
Abstract
The object of the present invention is to provide a heterojunction bipolar transistor with high breakdown tolerance which can be manufactured at a high reproducibility and a high yield, the heterojunction bipolar transistor includes: a sub-collector layer; a collector layer formed on the sub-collector layer; a base layer formed on the collector layer; and an emitter layer, which is formed on the base layer and is made of a semiconductor that has a larger bandgap than a semiconductor of the base layer, in which the collector layer includes: a first collector layer formed on the sub-collector layer; a second collector layer formed on the first collector layer; and a third collector layer formed between the second collector layer and the base layer, a semiconductor of the first collector layer differs from semiconductors of the third collector layer and the second collector layer, and an impurity concentration of the second collector layer is lower than an impurity concentration of the sub-collector layer and higher than an impurity concentration of the third collector layer.