The present invention is generally directed to a method and a structure for
calibrating a scatterometry-based metrology tool used to measure
dimensions of features on a semiconductor device. In one illustrative
embodiment, the method comprises measuring a critical dimension of at
least one production feature formed above a wafer using a scatterometry
tool, measuring at least one of a plurality of grating structures formed
above the wafer using the scatterometry tool, each of the grating
structures having a different critical dimension, and correcting the
measured critical dimension of the at least one production feature based
upon the measurement of the at least one grating structure. In further
embodiments, the method comprises forming a plurality of production
features above a wafer, forming a plurality of grating structures above
the wafer, each of the grating structures comprised of a plurality of
features each having a target critical dimension that thereby defines a
critical dimension of the grating structure, each of the grating
structures having a different critical dimension, measuring a critical
dimension of at least one of the production features using a scatterometry
tool, measuring at least one of the grating structures using the
scatterometry tool to determine a measured critical dimension of at least
one feature of the at least one grating structure, and correcting the
measured critical dimension of the at least one production feature based
upon a comparison between the measured critical dimension of the at least
one feature on the at least one grating structure and the target critical
dimension of the feature on the at least one grating structure.
