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:
Oct. 24, 2006
Filed:
Nov. 24, 2004
John Kevin Twynam, Yamatokooriyama, JP;
John Kevin Twynam, Yamatokooriyama, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
A bipolar transistor of the present invention comprises a collector layer made of an n-type semiconductor and an emitter layer made of an n-type semiconductor provided on this collector layer. A gate layer for injecting p-type carriers (holes) into the emitter layer is provided on the emitter layer. A p-type carrier retaining layer is formed between the collector layer and the emitter layer. The p-type carrier retaining layer temporarily retains the p-type carriers that are injected from the gate layer into the emitter layer and diffused in the emitter layer and reach the p-type carrier retaining layer. The bipolar transistor has a structure whose performance is not influenced by sheet resistance of the base layer, and is able to exhibit a high current gain even in a high-frequency region.