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:
Nov. 13, 1979
Filed:
Jul. 26, 1978
Henry Kressel, Elizabeth, NJ (US);
Mark A Spak, Edison, NJ (US);
RCA Corporation, New York, NY (US);
Abstract
A p-n junction silicon semiconductor device passivated with a first layer of oxygen-doped polycrystalline silicon and a second layer of silicon nitride, is treated to provide contact openings through to the silicon substrate by first depositing an undoped polycrystalline silicon layer over the silicon nitride layer, coating with photoresist, exposing and developing the photoresist to provide an opening to the polycrystalline silicon layer, etching through said latter layer with a particular etchant solution that etches large diameter openings at a faster rate than small diameter openings, and etching through the passivating layers whereby the desired contact opening is etched through to the substrate but pinhole openings less than about 2 microns in diameter in the photoresist layer are not propagated through the passivating layers.