Contaminant analyzing metrology system, lithographic apparatus, and methods thereof

An inspection method comprising:

• irradiating a surface of an object with a broadband illumination beam having a continuous spectral range;
• receiving scattered radiation at a detector, the scattered radiation including radiation scattered from the surface and radiation scattered by a structure near the surface;
• generating a detection signal representative of an optical response to the broadband illumination beam based on the received scattered radiation;
• analyzing the detection signal;
• and
• distinguishing, based on the analyzing, between a spurious signal corresponding to one or more internal reflections from the structure and a defect signal corresponding to a defect on the surface, wherein the spurious signal is diminished for at least a portion of the continuous spectral range.

A lithography apparatus comprising:

• an illumination apparatus configured to illuminate a pattern of a patterning device;
• a projection system configured to project an image of the pattern onto a substrate;
• and
• a metrology system comprising:
• an illumination system configured to generate a broadband illumination beam having a continuous spectral range and to illuminate a surface of an object with the broadband illumination beam,
• a detection system configured to receive radiation scattered at the surface and by a structure near the surface and to generate a detection signal based on an optical response to the broadband illumination beam, and
• processing circuitry configured for:
• analyzing the detection signal, and
• distinguishing, based on the analyzing, between a spurious signal corresponding to one or more internal reflections from the structure and a defect signal corresponding to a defect on the surface,
• wherein the spurious signal is diminished for at least a portion of the continuous spectral range.