METHOD FOR DETERMINING THE COMPLETE ELIMINATION OF A THIN LAYER ON A NON PLANAR SUBSTRATE

摘要

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.