Inspection method and apparatus for inspecting a particle, if any, on a substrate having a pattern

An inspection apparatus, comprising:

• first light producing means for producing first light having a first wavelength, and second light having a second wavelength, different from the first wavelength;
• second light producing means for producing third light having a third wavelength, and fourth light having a fourth wavelength, different from the third wavelength;
• light projecting means for projecting at least the first light and the third light to a position of inspection;
• first detecting means for detecting heterodyne interference light produced on the basis of the second light and light scattered at the inspection position as a result of irradiation by the first light;
• and
• second detecting means for detecting heterodyne interference light produced on the basis of the fourth light and light scattered at the inspection position as a result of irradiation by the third light.

An inspection apparatus for inspecting a particle, if any, on a substrate having a pattern, said apparatus comprising:

• light producing means for producing (i) first light having a first state of polarization and a first wavelength, and (ii) second light having a second state of polarization, different from the first state of polarization and a second wavelength, different from the first wavelength;
• light projecting means for projecting at least the first light to a position of inspection upon the substrate;
• first detecting means for detecting heterodyne interference light produced on the basis of the second light and light scattered in a first direction from the inspection position as a result of irradiation with the first light;
• second detecting means for detecting heterodyne interference light produced on the basis of the second light and light scattered in a second direction, different from the first direction, from the inspection position as a result of irradiation with the first light;
• and
• inspecting means for inspecting a particle, if any, on the substrate on the basis of outputs of said first and second detecting means.

An inspection method for inspecting a particle, if any, on a substrate having a pattern, said method comprising the steps of:

• producing (i) first light having a first state of polarization and a first wavelength, and (ii) second light having a second state of polarization, different from the first state of polarization, and a second wavelength, different from the first wavelength;
• projecting at least the first light to a position of inspection upon the substrate;
• detecting heterodyne interference light produced on the basis of the second light and light scattered at the inspection position and having its state of polarization changed, by the scattering, from the first state of polarization;
• and
• inspecting a particle, if any, on the substrate on the basis of the detection in said detecting step.