Contaminant identification metrology system, lithographic apparatus, and methods thereof

An inspection method comprising:

• irradiating an object simultaneously with a first illumination beam at a first wavelength and a second illumination beam at a second wavelength, the first wavelength being different from the second wavelength;
• receiving scattered radiation by a particle present at a surface of the object at the first wavelength;
• generating a detection signal based on the received scattered radiation;
• analyzing the detection signal;
• and
• determining a characteristic of the particle based on the detection signal.

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 including:
• an illumination system configured to generate a first illumination beam at a first wavelength and a second illumination beam at a second wavelength, the first wavelength being different from the second wavelength, and to irradiate an object simultaneously with the first illumination beam and the second illumination beam,
• a detection system configured to receive radiation scattered by a particle present at a surface of the object at the first wavelength and to generate a detection signal, and
• processing circuitry configured to determine a characteristic of the particle based on the detection signal.