Patent ID: 7099005
Filing Date: 2006-08-29
Classification: G01N,G02B

Abstract:
1. A method for finding a value of one or more parameters of a diffracting structure wherein a measurement is carried out by directing a polychromatic beam of electromagnetic radiation at said diffracting structure and detecting corresponding changes in polarization state of a diffraction of said beam at a number of wavelengths from said structure, comprising: carrying out a measurement of the structure to obtain measured changes in polarization state of a diffraction from the structure; providing a set of change in polarization state data of the diffraction at the wavelengths corresponding to a first set of values of said one or more parameters; and performing an optimized estimation within a neighborhood of the set of change in polarization state data using said measured changes in polarization state to arrive at a second set of values of the one or more parameters.