Integrated use of model-based metrology and a process model

A method comprising:

• providing illumination radiation to a target structure fabricated on a semiconductor wafer, the illumination radiation provided by an illumination source of a metrology tool;
• detecting an amount of radiation from the target structure in response to the illumination radiation, the amount of radiation detected by a detector of the metrology tool;
• generating a measured response associated with the target structure based on the detected radiation, the measured response comprising an amount of measurement data;
• determining one or more process parameter values characterizing a process employed to generate the target structure based on the amount of measurement data and an integrated measurement model of the target structure, wherein the integrated measurement model is based on a process based target model that constrains values of one or more of the set of geometric parameters characterizing the target structure based on a range of achievable values of one or more fabrication process parameters of the process based target model and a metrology based target model that predicts the measured response based on a model of an interaction of the target structure with the metrology tool;
• and
• storing the one or more process parameter values in a memory.

A system comprising:

• an optical metrology tool including an illumination source providing illumination radiation to a target structure fabricated on a semiconductor wafer and a detector detecting an amount of radiation from the target structure in response to the illumination radiation, the optical metrology tool configured to generate a measured response associated with the target structure based on the detected radiation, the measured response comprising an amount of measurement data;
• and
• a non-transitory, computer-readable medium, storing instructions that, when executed by one or more processors, cause the one or more processors to:
• determine a set of parameter values characterizing the target structure based on a fitting of the amount of measurement data to an integrated measurement model of the target structure, wherein the integrated measurement model is based on a process based target model that constrains values of one or more of the set of geometric parameters characterizing the target structure based on one or more fabrication process parameters, of the process based target model by mathematically linking values of one or more parameters of the process based target model to values of one or more of the set of geometric parameters characterizing the target structure and a metrology based target model that predicts the measured response based on a model of an interaction of the target structure with the metrology tool;
• and
• store the set of parameter values in a memory.

A system comprising:

• an illumination source of a metrology tool that provides illumination radiation to a target structure fabricated on a semiconductor specimen;
• a detector of the metrology tool that detects light from the target structure in response to the illumination light and generates a measured spectral response, the measured spectral response comprising an amount of measurement data;
• a non-transitory, computer-readable medium, storing instructions that, when executed by one or more processors, cause the one or more processors to:
• determine one or more process parameter values characterizing a process employed to generate the target structure based on the amount of measurement data and an integrated measurement model of the target structure, wherein the integrated measurement model is based on a process based target model that constrains values of one or more of the set of geometric parameters characterizing the target structure based on a range of achievable values of one or more fabrication process parameters of the process based target model and a metrology based target model that predicts the measured response based on a model of an interaction of the target structure with the metrology tool;
• and
• store the one or more process parameter values in a memory.