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:
Jul. 10, 1979
Filed:
Oct. 25, 1977
Narasipur G Anantha, Hopewell Junction, NY (US);
Harsaran S Bhatia, Wappingers Falls, NY (US);
James L Walsh, Hyde Park, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method for manufacturing a high performance bipolar device and the resulting structure which has a very small emitter-base spacing is described. The small emitter-base spacing, reduces the base resistance compared to earlier device spacing and thereby improves the performance of the bipolar device. The method involves providing a silicon semiconductor body having regions of monocrystalline silicon isolated from one another by isolation regions and a buried subcollector therein. A base region is formed in the isolated monocrystalline silicon. A mask is formed on the surface of the silicon body covering those regions designated to be the emitter and collector reach-through regions. A doped polycrystalline silicon layer is then formed through the mask covering the base region and making ohmic contact thereto. An insulating layer is formed over the polysilicon layer. The mask is removed from those regions designated to be the emitter and collector reach-through regions. The emitter junction is then formed in the base region and the collector reach-through formed to contact the buried subcollector. Electrical contacts are made to the emitter and collector. The doped polycrystalline silicon layer is the electrical contact to the base regions.