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:
Apr. 28, 1992
Filed:
May. 21, 1991
Applicant:
Inventors:
Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ; H01L / ;
U.S. Cl.
CPC ...
437 31 ; 437101 ; 437937 ; 148D / ; 148D / ; 357-2 ; 357 16 ; 357 34 ;
Abstract
A bipolar hetero-junction transistor has an emitter formed which consists of doped and hydrogenated semiconductor material which is at least partly in amorphous form. A high current gain (.beta.) is obtained due to the wide bandgap in the emitter material. Preferably, the layer forming the emitter consists of microcrystalline silicon which is doped and hydrogenated. This yields a small base resistance which is preferable for high frequency purposes. The amorphous bipolar hetero-junction transistor can be produced by a CVD-technique, by using a plasma or by photodissociation. The transistor having a microcrystalline emitter layer can be produced by one of the above methods or by heating an amorphous emitter layer.