Metrology mark characterization device and optical metrology system

摘要

PROBLEM TO BE SOLVED: To improve an optical measurement error caused by distortion of a metrology mark.;SOLUTION: A measuring system 12 configured to irradiate the metrology mark 10 and record a portion of a reflected, a transmitted, or both, electromagnetic field, and a characterization device 20 configured to determine a mark shape parameter indicative of the structure of the metrology mark 10 from the recorded field, are provided. The characterization device 20 comprises: a field derivative calculation unit 16 configured to calculate a first order derivative, a higher order derivative, or both, of an expected field with respect to the mark shape parameter; and an optimization unit 18 configured to use the outputs from a field calculation unit 14 and the field derivative calculation unit 16 to determine an optimized mark shape parameter for which the expected field substantially matches the recorded field.;COPYRIGHT: (C)2007,JPO&INPIT