Inspection apparatus, lithographic apparatus, and device manufacturing method

A method of determining substrate parameters, the method comprising:

• directing a first beam through a catadioptric objective onto the substrate such that the first beam reflects from the substrate;
• forming a first image of the substrate using the reflected first beam;
• determining a first parameter of the substrate using the first image;
• directing a second beam through a refractive objective onto the substrate such that the second beam reflects from the substrate;
• forming a second image of the substrate using the reflected second beam;
• and
• determining a second parameter of the substrate using the second image,
• wherein the first beam has a first spectral range and the second beam has a second spectral range, the second spectral range being different than the first spectral range.

An inspection apparatus for optically determining dimensional parameters of a wafer, the inspection apparatus comprising:

• an illumination system configured to receive a first beam and to produce second and third beams therefrom;
• a catadioptric objective configured to direct the second beam to reflect from the wafer;
• a first sensor configured to detect a first image created by the reflected second beam;
• a refractive objective configured to direct the third beam to reflect from the wafer;
• a second sensor configured to detect a second image created by the reflected third beam;
• and
• in order from a radiation source:
• a lens doublet configured to be adjustable along an optical axis;
• a rotatable prism polarizer;
• a pupil-defining aperture;
• and
• a mirror relay optical system configured to image the pupil-defining aperture into a plane of an entrance pupil of the catadioptric objective and into a plane of an entrance pupil of the refractive objective.

An inspection apparatus for optically determining dimensional parameters of a wafer, the inspection apparatus comprising:

• an illumination system configured to receive a first beam and to produce second and third beams therefrom;
• a catadioptric objective configured to direct the second beam to reflect from the wafer;
• a first sensor configured to detect a first image created by the reflected second beam;
• a refractive objective configured to direct the third beam to reflect from the wafer and comprising:
• a front lens group having front and back meniscus lenses,
• a middle lens group having a first doublet, a second doublet, a triplet, and a doublet in order from a front to a back of the refractive objective, and
• a back lens group having a negative doublet;
• and
• a second sensor configured to detect a second image created by the reflected third beam.