Process window based on defect probability

A computer product comprising a non-transitory computer-readable medium having instructions, the instructions, upon execution by a computer system, configured to cause the computer system to at least:

• obtain (i) a functional behavior of a parameter of a feature on a substrate defined as a function of the process variable based on measurements of the parameter and data related to a process variable of a patterning process used to generate the feature, (ii) measurements of a failure rate of the feature, and (iii) a probability density function of the process variable for a setting of the process variable;
• convert the probability density function of the process variable for the setting to a probability density function of the parameter for the setting based on a conversion function, wherein the conversion function is determined based on the function of the process variable;
• and
• determine a parameter limit of the parameter based on the probability density function of the parameter for the setting and the measurements of the failure rate of the feature.