METROLOGY METHODS AND APPRATUSES

摘要

Disclosed is a method of determining a performance parameter or a parameter derived therefrom, the performance parameter being associated with a performance of a lithographic process for forming one or more structures on a substrate subject to the lithographic process. The method comprises obtaining a probability description distribution comprising a plurality of probability descriptions of the performance parameter, each probability description corresponding to a different position on the substrate and decomposing each probability description into a plurality of component probability descriptions to obtain a plurality of component probability description distributions. A component across-substrate-area model is determined for each of said plurality of component probability descriptions, which models its respective component probability description across a substrate area; and a value for said performance parameter or parameter derived therefrom is determined based on the component across-substrate-area models.