Patent ID: 8643842

Claim:
A method for characterizing properties of an article having a multi-layer structure comprising a multiplicity of sites comprising different periodic patterns, the method comprising: providing a theoretical model of prediction indicative of optical properties of different stacks defined by geometrical and material parameters of corresponding sites, said sites being common in at least one of geometrical parameter and material parameter; selecting one or more parameters of the article to be used for optimizing said theoretical model, the selecting comprising analyzing sensitivity of said theoretical model to variation of each of the selected parameters, analyzing correlation between said selected parameters, and upon identifying that the correlation does not satisfy a predetermined condition, changing at least one of the geometrical parameters of one of the stacks; performing optical measurements on at least two different stacks of the article and generating optical measured data indicative of the geometrical parameters and material composition parameters for each of the measured stacks; processing the optical measured data, said processing comprising simultaneously fitting said optical measured data for the multiple measured stacks with said theoretical model and extracting said at least one common parameter, thereby enabling to characterize the properties of the multi-layer structure within the single article; wherein any of said providing, performing, and processing are implemented in a machine.