DETERMINING PROFILE PARAMETERS OF A STRUCTURE USING APPROXIMATION AND FINE DIFFRACTION MODELS IN OPTICAL METROLOGY

摘要

A method for determining profile parameters of structure is provided to accurately determine the profile of structure by using the profile model which accurately characterizes structure. The simulated approximation diffraction signal is generated based on the approximation diffraction model of structure. The approximation diffraction signal simulated from simulated precision diffraction signals is subtracted and the set of differential diffraction signals is obtained(710). Differential diffraction signals are coupled with profile parameters and then produce the library. The measured diffraction signal which is adjusted by the simulated approximation diffraction signal is matched to the library to determine one or more profile parameters of structure(724).