Apparatus and method for process-window characterization

A tangible, non-transitory, machine readable media storing instructions that when executed by a data processing apparatus effectuate operations comprising:

• obtaining, with one or more computers, a set of inspection locations for a pattern, the pattern defining features to be applied to a substrate with a patterning process, the set of inspection locations corresponding to a subset of the features, the subset of features being selected from among the features according to sensitivity of the respective features to variation in one or more process characteristics of the patterning process;
• simulating, with one or more computers, a patterning process with a plurality of different simulations, each under different process characteristics, and each with at least some of the same features in a pattern;
• determining, for each of the variations in the process characteristics, whether at least some of the subset of features yielded unacceptable patterned structures on the one or more substrates at corresponding inspection locations.