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. 26, 1980
Filed:
Dec. 22, 1977
Arup Bhattacharyya, Essex Center, VT (US);
Francis W Wiedman, III, Stowe, VT (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A semiconductor structure, formed within a recessed oxide isolation region, includes a semiconductor substrate of a first conductivity type within which a collector of opposite conductivity type is formed below the surface of the substrate and extending in part to the surface of the substrate for ease of contact. A first layer of doped polycrystalline silicon or polysilicon is formed on a first portion of the surface of the substrate and in electrical contact with the substrate which acts as the base of a transistor. The first polysilicon layer is oxidized to form an outer insulating layer thereover. A second doped polysilicon layer is disposed over the outer insulating layer onto a second portion of the surface of the substrate so as to be spaced from the first portion by only the thickness of the outer insulating layer on the first polysilicon layer. The dopant in the second polysilicon layer is driven into the surface of the semiconductor substrate to form an emitter therein. Means, which may include a portion of the second polysilicon layer, are provided for electrically contacting the collector to thus form a completed compact bipolar transistor which has very high performance.