| 摘要 |
<p>The invention relates to a method for measuring thickness variations in a layer of a multilayer semiconductor structure, characterised in that it comprises: acquiring, via an image acquisition system, at least one image of the surface of said structure, said image being obtained by reflecting an almost monochromatic light flux from the surface of said structure; and processing said at least one acquired image in order to determine, from variations in the intensity of the light reflected from said surface, variations in the thickness of said layer to be measured, and in that the wavelength of said almost monochromatic light flux is chosen to correspond to a minimum of the sensitivity of the reflectivity of a layer of the structure other than the layer the thickness variations of which must be measured, said sensitivity of the reflectivity of a layer being equal to the ratio of: the difference between the reflectivities of two multilayer structures for which the layer in question has a given thickness difference; to said given thickness difference, the thicknesses of the other layers being for their part identical in the two multilayer structures. The invention also relates to a measuring system implementing said method.</p> |
