Inspection apparatus, lithographic apparatus, and device manufacturing method

摘要

An inspection apparatus includes an illumination system configured to receive a first beam and to produce second and third beams from the first beam, and a catadioptric objective configured to direct the second beam to reflect from a wafer. The inspection apparatus includes a first sensor configured to detect a first image created by the reflected second beam. The inspection apparatus also includes a refractive objective configured to direct the third beam to reflect from the wafer, and a second sensor configured to detect a second image created by the reflected third beam. In one embodiment, the first and second images can be used for CD measurements. In one embodiment, the second beam has a spectral range from about 200 nm to about 425 nm, and the third beam has a spectral range from about 425 nm to about 850 nm. The inspection apparatus can also include a third sensor configured to detect a third image created by the third beam reflected from the wafer. The third image can be used for OV measurements.