| 摘要 |
The subject invention relates to broadband optical metrology tools for performing measurements of patterned thin films on semiconductor integrated circuits. Particularly a family of optical designs for broadband, multi-wavelength, DUV-IR (185<lambd<900 nm) all-refractive optical systems. The designs have net focusing power and this is achieved by combining at least one positively powered optical element with one negatively powered optical element. The designs have small spot-size over the wavelength range spanning 185-900 nm with substantially reduced spherical aberration, axial color, sphero-chromatism and zonal spherical aberration. The refractive optical systems are broadly applicable to a large class of broadband optical wafer metrology tools including spectrophotometers, spectroscopic reflectometers, spectroscopic ellipsometers and spectroscopic scatterometers.
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