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. 16, 1993
Filed:
Jul. 19, 1991
Jean Galvier, Saint Martin D'Heres, FR;
Philippe Gayet, Saint Vincent De Mercuze, FR;
Annie Tissier, Saint Ismier, FR;
France Telecom (CNET), Paris, FR;
Abstract
A method for determining the complete elimination of a thin layer (3) deposited on a substrate (1) includes the steps of providing on an area of the substrate (1) an optical diffraction grating (2, 2'), the thin layer deposited on the substrate also covering this diffraction grating, and the etching of the thin layer being also carried out in the area of the diffraction grating; illuminating the grating (2, 2') with a monochromatic light beam; and observing the evolution of the diffracted light during the etching of the thin layer, in order to determine the moment when the material of the thin layer is entirely removed.