Optical metrology of lithographic processes using asymmetric sub-resolution features to improve measurement

摘要

A process for calibrating a model is provided. This process obtains training data including scattered radiation information from multiple structures, each piece of the scattered radiation information associated with a separate process condition that is characteristic of the patterning process of each structure. And using one or more processors to calibrate the model using the training data by determining a first ratio that relates a change in one of the process characteristics to a corresponding change in the scattered radiation information; Including. [Selection] Figure 4