Patent ID: 7860686

Claim:
A process of geometrical characterisation of a structure, wherein the structure is illuminated, this structure then providing an optical response, this process enabling a two-dimensional or three-dimensional image of the structure to be obtained starting from the optical response of this structure, this process being characterised in that it comprises the following successive steps: (1) acquiring the optical response of the structure, (2) defining an elementary geometrical structure, as a base element capable of enabling decomposition of the structure to be characterised into one or more base elements, (3) determining at least one geometrical parameter of the base element and attributing a value to each geometrical parameter, (4) implementing a regression of the values of the geometrical parameter(s) of the base element starting from a regression algorithm capable of determining modified values of said geometrical parameter(s) in order to make a difference between a theoretical optical response of the base element, whose geometrical parameter(s) has (have) been determined, and the acquired optical response of the structure at most equal to a determined threshold value, and (5) if the difference between the theoretical optical response and the acquired optical response is greater than this threshold value, making a new subdivision of one or more base elements into at least two other base elements, and for each base element recommencing the process starting from step (3) thereof; if the difference is less than or equal to the threshold value, assembling a set of base elements with the determined values of their geometrical parameters to obtain an image of the structure, and if the difference is greater than the threshold value, recommencing the process at step (5).