Patent ID: 7187456

Claim:
A method of optical measurements on a patterned structure having an array of spaced-apart metal-containing regions located within at least one substantially transparent layer, the method comprising: a) providing an optical model, based on features of a structure having an array of spaced-apart metal-containing regions located within at least one substantially transparent layer, which features are defined by a certain process of the structure manufacturing, the optical model being configured for determining theoretical data representative of spectral characteristics of light returned from the structure and for calculating a thickness of the metal-containing region of the structure; b) applying optical measurements to said patterned structure, by illuminating it with incident radiation of a preset substantially wide wavelength range, detecting light returned from the patterned structure, and obtaining measured data representative of spectral characteristics of the returned light within said wavelength range; c) processing and analyzing the measured data using said theoretical data, to determine a thickness of the metal-containing region of the patterned structure under measurements.