Patent ID: 7382447

Claim:
A method for determining optical aberrations of a photolithographic system, the method comprising: correlating values of a first set of two or more shape parameters with values of a first set of one or more process parameters to produce dependencies, the values of the first set of two or more shape parameters being determined via scatterometry measurement techniques; determining values of a second set of two or more shape parameters associated with multiple structures in a lithographic field via scatterometry measurement techniques; determining values of a second set of one or more process parameters associated with forming the multiple structures by comparing the second set of two or more shape parameters with the correlated dependencies; determining optical aberrations from lithographic process parameters determined for multiple scatterometry measurement sites in the lithographic field; and using the determined optical aberrations to determine corrections to one or more optical elements of the photolithographic system in order to optimize the photolithographic system and to minimize negative effects of the optical aberrations.