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:
Aug. 11, 1992
Filed:
Apr. 23, 1991
Richard J Murphy, Hopewell Junction, NY (US);
Jerome D Schick, LaGrangeville, NY (US);
Howard R Wilson, Poughkeepsie, NY (US);
International Business Machines Corp., Armonk, NY (US);
Abstract
A method and apparatus for determining the thickness of an interfacial oxide film intermediate to a polysilicon layer of a first conductivity type and a silicon substrate of a second conductivity type supporting a p-n junction. Radiant energy, preferably in the form of light, is directed on to the top surface of the polysilicon layer thereby stimulating carriers which concentrate at the interfacial oxide film, allowing the excited carriers to diffuse across the oxide film, and creating a short circuit, the magnitude of which is inversely related to the thickness of the interfacial oxide film.