SPECTROGRAPHIC METROLOGY OF PATTERNED WAFERS

摘要

Light reflected from respective image elements of a workpiece is channeled through respective light channeling elements to respective locations of a spectrographic light disperser. Spectral distributions of the respective image elements produced by the spectrographic light disperser are recorded. A processor groups similar spectral distributions into respective groups of mutually similar distributions, and classifies the groups by the number of distributions contained in each group.