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:
Sep. 05, 2017
Filed:
Dec. 12, 2011
Lin Cheng, Chapel Hill, NC (US);
Anant K. Agarwal, Chapel Hill, NC (US);
Sei-hyung Ryu, Cary, NC (US);
Lin Cheng, Chapel Hill, NC (US);
Anant K. Agarwal, Chapel Hill, NC (US);
Sei-Hyung Ryu, Cary, NC (US);
Cree, Inc., Durham, NC (US);
Abstract
The present disclosure relates to a bipolar junction transistor (BJT) structure that significantly reduces current crowding while improving the current gain relative to conventional BJTs. The BJT includes a collector, a base region, and an emitter. The base region is formed over the collector and includes at least one extrinsic base region and an intrinsic base region that extends above the at least one extrinsic base region to provide a mesa. The emitter is formed over the mesa. The BJT may be formed from various material systems, such as the silicon carbide (SiC) material system. In one embodiment, the emitter is formed over the mesa such that essentially none of the emitter is formed over the extrinsic base regions. Typically, but not necessarily, the intrinsic base region is directly laterally adjacent the at least one extrinsic base region.