Patent ID: 6621568
Filing Date: 2003-09-16
Classification: G01N

Abstract:
A defect inspecting apparatus for macroscopically inspecting a defect of an object having a periodic fine pattern, said apparatus comprising:a dark field illumination optical system that illuminates a region of the object with substantially parallel illumination light in a direction having a predetermined first inclined angle relative to an inspection surface of the object, the region being larger than a size of one fine pattern; an imaging optical system that images the region of the object illuminated with the illumination light, the imaging optical system having an imaging lens and an imaging element having a lower resolution in comparison to the fine pattern imaged by the imaging lens; and defect detecting means that detects the defect by processing image data thus imaged; wherein an optical axis direction of the imaging optical system is set between a direction of zero-order diffraction light of the illumination light and a direction of 1st-order diffraction light that is formed, with respect to the direction of the zero-order diffraction light, at a minimal diffraction angle &agr; min defined by a maximum period n (max) of the fine pattern to be inspected and a minimal wavelength &lgr; (min) of the illumination light; and wherein a sum of an aperture angle &ggr; of the illumination light and an aperture angle &egr; of the imaging lens is set to be smaller than a diffraction angle &agr;.