Patent ID: 8531679

Claim:
An optical system for determining one or more parameters of at least one via-hole in an structure, the optical system comprising: an illumination system for producing at least one light beam and directing it on a sample in a region of the structure containing at least one via-hole; a detection system configured and operable to collect a pattern of light reflected from the illuminated region, the light pattern being indicative of one or more parameters of said via-hole; and, a control system connected to the detection system, the control system comprising a memory utility for storing a predetermined theoretical model comprising data representative of a set of parameters describing via-holes reflected pattern, an image generation utility configured and operable to generate model images using said predetermined theoretical model, and a data processing and analyzing utility configured and operable to receive and analyze an image received from said detection system and being indicative of the detected light pattern and the generated model image, fit the received image to the generated model image, and determine one or more parameters of said via-hole from the set of parameters of the theoretical model that corresponds to the model image with a predefined fitting range.