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:
Feb. 14, 1995
Filed:
Feb. 08, 1994
Applicant:
Inventor:
S Noor Mohammad, Hopewell Junction, NY (US);
Assignee:
International Business Machines Corporation, Armonk, NY (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
437 31 ; 437133 ;
Abstract
A Double Heterojunction Bipolar Transistor (DHBT) and the method of fabrication therefor. First a layered wafer is prepared on a semi-insulating GaAs substrate. The bottom wafer layer is n.sup.+ GaAs, followed by n.sub.- AlGaAs, a thin layer of n AlGaAs (which form the DHBT's collector) and a base layer of p.sup.+ GaAS. A layered plug fills a trench etched in the base layer. The bottom two plug layers are AlGaAs and the top plug layer is GaAs. Next, an emitter is ion-implanted into the plug core and an extrinsic base region is ion-implanted. Finally, base, emitter and collector contacts are formed.