Methodology for extracting effective lens aberrations using a neural network

摘要

A method (250) of extracting effective imaging system aberrations from test data collected from test structures (220) constructed from a lithography system having an imaging system associated therewith includes inputting (264) experimental critical dimension data corresponding to fabricated features (220) on a substrate (212) to a neural network (208). The method (250) also includes inputting (266) nominal critical dimension data corresponding to the fabricated features on the substrate (212) to the neural network (208) and determining (268) the effective aberrations of the imaging system associated with the lithography system used to fabricate the features (220) using the neural network (208).