Patent ID: 6657736
Filing Date: 2003-12-02
Classification: G01B,G01N,G03F

Abstract:
A method of determining a line profile in a patterned structure for controlling a process of manufacture thereof, wherein the patterned structure comprises a plurality of different layers, the pattern in the structure being formed by patterned regions and un-patterned regions, the method comprising:providing reference data in the form of a library of multiple spectra of different possible profiles of structures similar to the structure under measurement and their corresponding sets of structure parameters, said library being obtained by sparsely sampling an entire multi-dimensional space of possible profiles; carrying out at least two measurements, each of the measurements utilizing illumination of the structure with a broad wavelengths band of incident light which is directed on the structure at a certain angle of incidence, detection of spectral characteristics of light returned from the structure, and generation of measured data indicative of the structure line profile which is a function of a plurality of parameters of the structure; analyzing the measured data obtained with one of the measurements and determining at least one parameter of the structure; and analyzing the measured data obtained with the other measurement by fitting this measured data with said reference data to determine a sub-space of some parameters of the structure, and utilizing said at least one parameter and said sub-space of the parameters for fitting this measured data to results of a multi-parameter model describing the profile of a patterned structure and thereby determining the profile of the structure under measurement.