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:
Mar. 25, 1997
Filed:
Mar. 27, 1996
Koji Kimura, Chigasaki, JP;
Hiroshi Naruse, Yokohama, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
An N type diffusion layer as a collector is formed on a P type silicon substrate, and a field oxide film is formed on this diffusion layer. An MoSi.sub.2 film is formed on this field oxide film and a first opening is formed on those field oxide film and MoSi.sub.2 film to expose the diffusion layer. An N type layer is selectively epitaxially grown only on the bottom of the first opening. A base layer is formed on the N type layer, the side wall of the first opening and the MoSi.sub.2 film. The base layer on the N type layer is formed by epitaxial growth, while the base layer on the side wall of the first opening and the MoSi.sub.2 film is formed in a polycrystalline state. A first silicon oxide film is formed on this based layer. The first silicon oxide film is thinner on the polycrystalline base layer than on the epitaxially grown base layer. The first silicon oxide film is subjected to anisotropic etching to expose only the surface of the epitaxially grown base layer. An N type silicon film as an emitter is selectively grown only on this exposed base layer.