Patent Document ID: 20090063077
Application ID: 11848214
Patent Flag: 0

Claim One:
1. A method of controlling a fabrication cluster using a library developed using an optical metrology model, the optical metrology model comprising a profile model, an approximation diffraction model, and a fine diffraction model, the method comprising: (a) developing a metrology model of a structure, the metrology model including a profile model, the profile model having profile parameters; (b) optimizing the metrology model, the optimized metrology model including an optimized profile model, (c) calculating a simulated approximation diffraction signal based on the approximation diffraction model of the structure; (d) generating a set of simulated fine diffraction signals from a set of profile parameters, the simulated fine diffraction signals generated using the optimized profile model of the structure; (e) generating a library of difference diffraction signals and corresponding profile parameters, the difference diffraction signal calculated by subtracting the simulated approximation diffraction signal from each of the simulated fine diffraction signal of the set of simulated fine diffraction signals; (f) determining a best match of a measured diffraction signal adjusted by the simulated approximation diffraction signal against the library of difference diffraction signals; (g) if one or more matching criteria are met, determining at least one profile parameter of the structure, else modifying the approximation diffraction model and iterating steps (c) through (g) until the one or more matching criteria are met; (h) transmitting the at least one profile parameter to a fabrication cluster wherein the fabrication cluster was used to create the structure, the fabrication cluster having process parameters and equipment settings; and (i) adjusting one or more process parameters or equipment settings of the fabrication cluster based on the at least one profile parameter.