Patent Document ID: 20020072003
Application ID: 09984640
Patent Flag: 0

Claim One:
1. A method of controlling a process to be applied to a patterned structure in a production run, the method comprising the steps of: (i) providing reference data including data representative of diffraction signatures corresponding to a group of different fields in a structure similar to said patterned structure in the production line, and data representative of a control window for the process parameters corresponding to a signature representative of desired process results, said group of different fields being characterized by different process parameters used in the manufacture of these fields; (ii) providing an expert system trained to be responsive to input data representative of a diffraction signature to provide output data representative of corresponding effective parameters of the process; (iii) applying optical measurements to at least one site on said patterned structure in the production line to obtain at least one diffraction signature of said patterned structure in the production line and generate data representative thereof; (iv) supplying the generated data to said expert system, which analyses the data to thereby determine effective parameters of the process applied to said patterned structure in the production line; and (v) analyzing said effective process parameters to determine deviation thereof from corresponding nominal values to thereby enable the process control.