Patent ID: 7221989

Claim:
A method of evaluating the adequacy of a profile model of a wafer structure to be used for process control of a fabrication process to fabricate the wafer structure, the profile modal including profile model parameters, the method comprising: a) selecting one or more types of process control to be used in controlling the fabrication process; b) selecting one or more profile model parameters to be measured in implementing the one or more selected types of process control; c) setting one or more statistical metric criteria that define an acceptable amount of variation ha measurements obtained using a first metrology tool and a second metrology tool, wherein the first metrology tool is a scatterometer; d) selecting a profile model to be used with the first metrology tool; e) obtaining a measurement of the one or more profile model parameters selected in b) using the first metrology tool and the profile model selected in d); f) obtaining a measurement of the one or more profile model parameters selected in b) using the second metrology tool; g) calculating the one or more statistical metric criteria based on the measurements of the one or more profile modal parameters obtained using the first and second metrology tools in e) and f); and h) comparing the one or more calculated statistical metric criteria to the one or more statistical metric criteria set in c) to evaluate the adequacy of the profile model selected in d).