Patent ID: 7747978

Claim:
A computer-implemented method for creating a focus-exposure model of a lithography process, comprising: selecting a set of process conditions within a predetermined process window of a lithography process, the set of process conditions being a subset of all possible process conditions within the process window, each process condition being an exposure value and a defocus value; selecting a model of the lithography process, the model including an optical model module, the model having a set of model parameters including focus, exposure, and a set of fitting parameters having variable values; simulating, using the computer, the lithography process at each of the set of process conditions using the model to produce simulated results, wherein values of the focus and exposure parameters are varied to correspond to the set of process conditions and the fitting parameter values are held constant; and calibrating, using the computer, the model by comparing the simulated results with actual results of the lithography process at all of the set of process conditions to produce a single focus-exposure model capable of simulating the lithography process at all possible process conditions within the predetermined process window.