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. 17, 1979
Filed:
Apr. 29, 1977
Francisco H De La Moneda, Reston, VA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method is disclosed to fabricate a Merged Transistor Logic (MTL) cell having vertical devices with higher beta and f.sub.T, and a lateral device with higher beta than available from conventionally fabricated cells. Features which contribute to these results include a p-type epitaxial layer, highly doped emitter and collector regions for the lateral PNP transistor, a contour for the base region of the lateral PNP which reinforces its transistor action in the bulk rather than at the surface of the epitaxial layer, a highly doped emitter for the vertical device, a uniform doping profile for the base region of the vertical device, dielectric isolation, and the use of heavily doped base regions to reduce injection of emitter current into inactive regions of the cell.