METHOD AND SYSTEM OF SELECTING A HYPOTHETICAL PROFILE TO USE IN OPTICAL METROLOGY, AND COMPUTER READABLE STORAGE MEDIUM THEREFOR

摘要

A hypothetical profile is used to model the profile of a structure formed on a semiconductor wafer to use in determining the profile of the structure using optical metrology. To select a hypothetical profile, sample diffraction signals are obtained from measured diffraction signals of structures formed on the wafer, where the sample diffraction signals are a representative sampling of the measured diffraction signals. A hypothetical profile is defined and evaluated using a sample diffraction signal from the obtained sample diffraction signals.