Patent ID: 7398508
Filing Date: 2008-07-08
Classification: G03F

Abstract:
1. A method for modeling a photolithography process comprising the steps of: receiving parameters indicative of a target pattern and characteristics of a partially coherent imaging system utilized to image said target pattern; decomposing said partially coherent imaging system into a series of coherent imaging systems, said series of coherent imaging systems being defined utilizing a plurality of eigen functions; determining an aerial image intensity distribution expected to be produced on a resist by the target pattern using said plurality of eigen functions and a function representing said target pattern; and determining an imaging model based on the aerial image, wherein said imaging model comprises a system pseudo intensity function (SPIF), said method further comprising the steps of: applying a constant threshold to the SPIF to generate contours; comparing the generated contours with expected contours; and adjusting weights of each term associated with each eigen function and generating a new SPIF if the generated contours are not within a predetermined tolerance of the expected contours.