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. 11, 1983
Filed:
Sep. 28, 1982
Applicant:
Inventor:
Tadashi Kiriseko, Kanagawa, JP;
Assignee:
Fujitsu Limited, Kawasaki, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ;
U.S. Cl.
CPC ...
2957 / ; 2957 / ; 29578 ; 29587 ; 148-15 ; 148175 ; 148187 ; 156628 ; 156653 ; 156657 ; 357 34 ; 357 50 ; 357 54 ; 357 59 ;
Abstract
A method for producing a bipolar transistor which has no emitter-base short and which attains a high density of integration. The method comprises the steps of forming a polycrystalline silicon layer on an anti-oxidation masking layer formed on a base region, selectively etching the polycrystalline silicon layer to form an opening, introducing impurities into the base region to form an emitter region, converting the polycrystalline silicon layer into an oxide layer whereby the size of the opening is reduced, selectively etching the anti-oxidation masking layer to form an emitter electrode opening, and forming electrodes.