Patent ID: 8072591

Claim:
An inspection system comprising: optics; an object support for mounting an object in a region of an object plane of the optics; a dark-field illumination light source; and an image detector having a radiation sensitive substrate disposed in a region of an image plane of the optics; wherein the optics provide an imaging beam path and a dark-field illumination beam path and comprise an objective lens, and a projection lens arranged such that the following elements are arranged in the imaging beam path in the following order; the object plane, the objective lens, and the radiation sensitive substrate, and such that the following elements are arranged in the dark-field illumination beam path in the following order: the dark-field light source, the projection lens and the object plane, wherein an orientation of chief rays of the illumination beam path varies across an object field imaged onto the radiation sensitive substrate by less than 5Â°; wherein an orientation of chief rays of the imaging beam path varies across the object field by less than 5Â°; wherein a numerical aperture of the imaging beam path on a side of the object plane is less than 0.1; wherein a numerical aperture of the illumination beam path on a side of the object plane is less than 0.1; and wherein at least one of the following relations is fulfilled: i) an object field diameter is greater than 200 mm and a total extension of the imaging beam path from the object plane to the image plane is less than 1100 mm; ii) the total extension of the imaging beam path from the object plane to the image plane divided by the object field diameter is less than 6.0; and iii) the diameter of the object field is greater than 0.6 times a diameter of the object.