Patent ID: 9360662
Filing Date: 2016-06-07
CPC Classification: B82Y,G02B,G03F,H04N,Y10S

Claim Text:
1. An optical measurement system for measuring a critical dimension of a nanostructured surface, the optical measurement system comprising: an image recording module comprising a microscope optical system which records a defocused image having a nonuniform degree of defocusing with respect to the nanostructured surface; an optical scheme parameter control module which sets and outputs to the microscope optical system optical scheme parameters for the microscope optical system; an image calculation module which receives the optical scheme parameters and calculates an image of the nanostructured surface; and a comparison module which compares the defocused image recorded by the image recording module and the image calculated by the image calculation module; wherein the microscope optical system comprises an objective lens, wherein a normal of the nanostructured surface of the sample is inclined by an angle θwith respect to an optical axis of the objective lens; and wherein the predetermined angle θsatisfies a condition: wherein α≈d