How to determine information about the patterning process, how to reduce errors in measurement data, how to calibrate the measurement process, and how to select measurement targets

摘要

This specification relates to the determination of information regarding the patterning process. In one method, measurement data is obtained from a measurement process applied to each of a plurality of measurement targets on a substrate. Measurement data for each metrology target includes at least a first contribution and a second contribution. The first contribution comes from the parameters of interest of the patterning process used to form the metrology target. The second contribution comes from errors in the measurement process. Such a method includes: obtaining information about an error in a measurement process using measurement data obtained from all of a plurality of measurement targets; And extracting the value of the parameter of interest for each metrology target using the obtained information about the error in the metrology process.