摘要:
An inspection apparatus includes an illumination system that receives a first beam and produces second and third beams from the first beam and a catadioptric objective that directs the second beam to reflect from a wafer. A first sensor detects a first image created by the reflected second beam. A refractive objective directs the third beam to reflect from the wafer, and a second sensor detects a second image created by the reflected third beam. The first and second images can be used for CD measurements. The second beam can have a spectral range from about 200 nm to about 425 nm, and the third beam can have a spectral range from about 425 nm to about 850 nm. A third sensor may be provide that detects a third image created by the third beam reflected from the wafer. The third image can be used for OV measurements.